From 957e10758a4168c883b12edc2e9a6b537c32b5fe Mon Sep 17 00:00:00 2001
From: Guy Sartorelli <guy.sartorelli@gmail.com>
Date: Thu, 26 Sep 2024 16:16:04 +1200
Subject: [PATCH] API Refactor template layer into its own module

Includes the following large-scale changes:
- Impoved barrier between model and view layers
- Improved casting of scalar to relevant DBField types
- Improved capabilities for rendering arbitrary data in templates
---
 src/Control/RSS/RSSFeed_Entry.php             |  16 +-
 src/Core/CustomMethods.php                    |  45 +-
 src/Dev/Backtrace.php                         |   6 +-
 src/Forms/CheckboxSetField.php                |   4 +-
 src/Forms/ConfirmedPasswordField.php          |   4 +-
 src/Forms/CurrencyField_Disabled.php          |   2 +-
 src/Forms/CurrencyField_Readonly.php          |   2 +-
 src/Forms/DatalessField.php                   |   8 +-
 src/Forms/DateField_Disabled.php              |   2 +-
 src/Forms/DropdownField.php                   |   6 +-
 src/Forms/FieldGroup.php                      |   6 +-
 src/Forms/FieldList.php                       |   4 +-
 src/Forms/FileField.php                       |   4 +-
 src/Forms/Form.php                            |   4 +-
 src/Forms/FormAction.php                      |   8 +-
 src/Forms/FormField.php                       |  31 +-
 src/Forms/FormScaffolder.php                  |   4 +-
 src/Forms/GridField/GridField.php             |   8 +-
 src/Forms/GridField/GridFieldDeleteAction.php |   2 +-
 src/Forms/GridField/GridFieldExportButton.php |   2 +-
 src/Forms/GridField/GridFieldImportButton.php |   2 +-
 src/Forms/GridField/GridFieldPrintButton.php  |   2 +-
 src/Forms/GridField/GridState_Component.php   |   2 +-
 src/Forms/HTMLEditor/HTMLEditorField.php      |  25 +-
 src/Forms/HTMLReadonlyField.php               |   2 +-
 src/Forms/HiddenField.php                     |   8 +-
 src/Forms/ListboxField.php                    |   4 +-
 src/Forms/LiteralField.php                    |   8 +-
 src/Forms/LookupField.php                     |   4 +-
 src/Forms/NullableField.php                   |   6 +-
 src/Forms/OptionsetField.php                  |   4 +-
 src/Forms/PrintableTransformation_TabSet.php  |   4 +-
 src/Forms/SearchableDropdownTrait.php         |   2 +-
 src/Forms/SelectionGroup.php                  |   4 +-
 src/Forms/SingleLookupField.php               |   4 +-
 src/Forms/TabSet.php                          |   2 +-
 src/Forms/ToggleCompositeField.php            |   2 +-
 src/Forms/TreeDropdownField.php               |   8 +-
 src/Forms/TreeDropdownField_Readonly.php      |   4 +-
 src/Forms/TreeMultiselectField.php            |  12 +-
 src/Forms/TreeMultiselectField_Readonly.php   |   4 +-
 src/Model/List/ListDecorator.php              |   4 +-
 src/Model/ModelData.php                       | 239 +++------
 src/Model/ModelDataCustomised.php             |  13 +-
 src/ORM/DataList.php                          |   3 +-
 src/ORM/DataObject.php                        |  17 +-
 src/ORM/EagerLoadedList.php                   |   2 +-
 src/ORM/FieldType/DBComposite.php             |   4 +-
 src/ORM/FieldType/DBField.php                 |   5 -
 src/ORM/FieldType/DBVarchar.php               |   2 +-
 src/ORM/Filters/SearchFilter.php              |   2 +-
 src/ORM/Relation.php                          |   5 +-
 src/ORM/UnsavedRelationList.php               |   5 +-
 src/PolyExecution/PolyOutput.php              |   3 -
 src/Security/Member.php                       |   6 +-
 src/Security/PermissionCheckboxSetField.php   |  12 +-
 src/View/CastingService.php                   | 100 ++++
 src/View/SSTemplateParser.peg                 |  42 +-
 src/View/SSTemplateParser.php                 |  60 ++-
 src/View/SSViewer.php                         |  12 +-
 src/View/SSViewer_DataPresenter.php           | 449 ----------------
 src/View/SSViewer_FromString.php              |   1 +
 src/View/SSViewer_Scope.php                   | 504 ++++++++++++++----
 src/View/ViewLayerData.php                    | 195 +++++++
 templates/RightLabelledFieldHolder.ss         |   2 +-
 .../Forms/CheckboxField_holder.ss             |   2 +-
 .../Forms/CheckboxField_holder_small.ss       |   2 +-
 .../SilverStripe/Forms/CompositeField.ss      |   4 +-
 .../Forms/CompositeField_holder.ss            |   2 +-
 .../Forms/CompositeField_holder_small.ss      |   4 +-
 templates/SilverStripe/Forms/FieldGroup.ss    |   2 +-
 .../Forms/FieldGroup_DefaultFieldHolder.ss    |   2 +-
 .../SilverStripe/Forms/FieldGroup_holder.ss   |   2 +-
 .../SilverStripe/Forms/FormField_holder.ss    |   2 +-
 .../Forms/FormField_holder_small.ss           |   2 +-
 .../GridFieldAddExistingAutocompleter.ss      |   2 +-
 .../GridField/GridFieldFilterHeader_Row.ss    |   2 +-
 .../GridField/GridFieldSortableHeader_Row.ss  |   2 +-
 .../HTMLEditorField_Toolbar_viewfile.ss       |   2 +-
 templates/SilverStripe/Forms/Includes/Form.ss |   4 +-
 .../Forms/OptionsetField_holder.ss            |   2 +-
 .../Includes/CMSMemberLoginForm.ss            |   4 +-
 .../forms/HtmlEditorField_holder_small.ss     |   2 +-
 tests/php/Forms/CheckboxFieldTest.php         |   6 +-
 tests/php/Forms/CheckboxSetFieldTest.php      |   4 +-
 tests/php/Forms/CompositeFieldTest.php        |  10 +-
 .../php/Forms/ConfirmedPasswordFieldTest.php  |   6 +-
 tests/php/Forms/CurrencyFieldDisabledTest.php |   4 +-
 tests/php/Forms/CurrencyFieldReadonlyTest.php |   6 +-
 tests/php/Forms/DatalessFieldTest.php         |   8 +-
 tests/php/Forms/DateFieldDisabledTest.php     |  14 +-
 tests/php/Forms/DropdownFieldTest.php         |  44 +-
 tests/php/Forms/FieldListTest.php             |   4 +-
 .../GridField/GridFieldActionMenuTest.php     |   4 +-
 .../GridField/GridFieldDeleteActionTest.php   |   4 +-
 .../GridField/GridFieldEditButtonTest.php     |   4 +-
 .../GridField/GridFieldPaginatorTest.php      |   4 +-
 tests/php/Forms/GridField/GridFieldTest.php   |  12 +-
 tests/php/Forms/GroupedDropdownFieldTest.php  |  10 +-
 .../Forms/HTMLEditor/HTMLEditorFieldTest.php  |   8 +-
 tests/php/Forms/ListboxFieldTest.php          |  12 +-
 tests/php/Forms/LookupFieldTest.php           |  16 +-
 tests/php/Forms/NullableFieldTests.php        |   6 +-
 tests/php/Forms/NumericFieldTest.php          |   4 +-
 tests/php/Forms/OptionsetFieldTest.php        |   6 +-
 .../PrintableTransformationTabSetTest.php     |   4 +-
 .../php/Forms/SearchableDropdownTraitTest.php |   2 +-
 tests/php/Forms/SelectionGroupTest.php        |   8 +-
 tests/php/Forms/SingleLookupFieldTest.php     |   4 +-
 tests/php/Forms/TextareaFieldTest.php         |   8 +-
 tests/php/Forms/TreeDropdownFieldTest.php     |   4 +-
 tests/php/Forms/TreeMultiselectFieldTest.php  |   8 +-
 tests/php/Model/ModelDataTest.php             |  21 +-
 tests/php/Model/ModelDataTest/NotCached.php   |   2 +-
 tests/php/ORM/Filters/EndsWithFilterTest.php  |  14 -
 .../ORM/Filters/PartialMatchFilterTest.php    |  14 -
 .../php/ORM/Filters/StartsWithFilterTest.php  |  14 -
 tests/php/ORM/LabelFieldTest.php              |   2 +-
 .../PermissionCheckboxSetFieldTest.php        |   4 +-
 tests/php/Security/PermissionTest.php         |   6 +-
 tests/php/View/SSViewerTest.php               | 142 +++--
 tests/php/View/SSViewerTest/TestFixture.php   |  93 ++--
 tests/php/i18n/i18nTestManifest.php           |   6 +-
 123 files changed, 1336 insertions(+), 1228 deletions(-)
 create mode 100644 src/View/CastingService.php
 delete mode 100644 src/View/SSViewer_DataPresenter.php
 create mode 100644 src/View/ViewLayerData.php

diff --git a/src/Control/RSS/RSSFeed_Entry.php b/src/Control/RSS/RSSFeed_Entry.php
index 1ebaae7e7de..810f2589649 100644
--- a/src/Control/RSS/RSSFeed_Entry.php
+++ b/src/Control/RSS/RSSFeed_Entry.php
@@ -47,7 +47,7 @@ class RSSFeed_Entry extends ModelData
      */
     public function __construct($entry, $titleField, $descriptionField, $authorField)
     {
-        $this->failover = $entry;
+        $this->setFailover($entry);
         $this->titleField = $titleField;
         $this->descriptionField = $descriptionField;
         $this->authorField = $authorField;
@@ -58,9 +58,9 @@ public function __construct($entry, $titleField, $descriptionField, $authorField
     /**
      * Get the description of this entry
      *
-     * @return DBField Returns the description of the entry.
+     * @return DBField|null Returns the description of the entry.
      */
-    public function Title()
+    public function getTitle()
     {
         return $this->rssField($this->titleField);
     }
@@ -68,9 +68,9 @@ public function Title()
     /**
      * Get the description of this entry
      *
-     * @return DBField Returns the description of the entry.
+     * @return DBField|null Returns the description of the entry.
      */
-    public function Description()
+    public function getDescription()
     {
         $description = $this->rssField($this->descriptionField);
 
@@ -85,9 +85,9 @@ public function Description()
     /**
      * Get the author of this entry
      *
-     * @return DBField Returns the author of the entry.
+     * @return DBField|null Returns the author of the entry.
      */
-    public function Author()
+    public function getAuthor()
     {
         return $this->rssField($this->authorField);
     }
@@ -96,7 +96,7 @@ public function Author()
      * Return the safely casted field
      *
      * @param string $fieldName Name of field
-     * @return DBField
+     * @return DBField|null
      */
     public function rssField($fieldName)
     {
diff --git a/src/Core/CustomMethods.php b/src/Core/CustomMethods.php
index 97f84f07d64..e6edc573894 100644
--- a/src/Core/CustomMethods.php
+++ b/src/Core/CustomMethods.php
@@ -36,6 +36,8 @@ trait CustomMethods
      */
     protected static $built_in_methods = [];
 
+    protected array $extraMethodsForInstance = [];
+
     /**
      * Attempts to locate and call a method dynamically added to a class at runtime if a default cannot be located
      *
@@ -175,7 +177,7 @@ protected function getExtraMethodConfig($method)
             $this->defineMethods();
         }
 
-        return self::class::$extra_methods[$lowerClass][strtolower($method)] ?? null;
+        return $this->extraMethodsForInstance[strtolower($method)] ?? self::class::$extra_methods[$lowerClass][strtolower($method)] ?? null;
     }
 
     /**
@@ -190,6 +192,9 @@ public function allMethodNames($custom = false)
 
         // Query extra methods
         $lowerClass = strtolower(static::class);
+        if ($custom && !empty($this->extraMethodsForInstance)) {
+            $methods = array_merge($this->extraMethodsForInstance, $methods);
+        }
         if ($custom && isset(self::class::$extra_methods[$lowerClass])) {
             $methods = array_merge(self::class::$extra_methods[$lowerClass], $methods);
         }
@@ -256,7 +261,7 @@ protected function findMethodsFrom($object)
      * @param string|int $index an index to use if the property is an array
      * @throws InvalidArgumentException
      */
-    protected function addMethodsFrom($property, $index = null)
+    protected function addMethodsFrom($property, $index = null, bool $static = true)
     {
         $class = static::class;
         $object = ($index !== null) ? $this->{$property}[$index] : $this->$property;
@@ -280,10 +285,18 @@ protected function addMethodsFrom($property, $index = null)
 
         // Merge with extra_methods
         $lowerClass = strtolower($class);
-        if (isset(self::class::$extra_methods[$lowerClass])) {
-            self::class::$extra_methods[$lowerClass] = array_merge(self::class::$extra_methods[$lowerClass], $newMethods);
+        if ($static) {
+            if (isset(self::class::$extra_methods[$lowerClass])) {
+                self::class::$extra_methods[$lowerClass] = array_merge(self::class::$extra_methods[$lowerClass], $newMethods);
+            } else {
+                self::class::$extra_methods[$lowerClass] = $newMethods;
+            }
         } else {
-            self::class::$extra_methods[$lowerClass] = $newMethods;
+            if (!empty($this->extraMethodsForInstance)) {
+                $this->extraMethodsForInstance = array_merge($this->extraMethodsForInstance, $newMethods);
+            } else {
+                $this->extraMethodsForInstance = $newMethods;
+            }
         }
     }
 
@@ -293,7 +306,7 @@ protected function addMethodsFrom($property, $index = null)
      * @param string $property the property name
      * @param string|int $index an index to use if the property is an array
      */
-    protected function removeMethodsFrom($property, $index = null)
+    protected function removeMethodsFrom($property, $index = null, bool $static = true)
     {
         $extension = ($index !== null) ? $this->{$property}[$index] : $this->$property;
         $class = static::class;
@@ -310,12 +323,22 @@ protected function removeMethodsFrom($property, $index = null)
         }
         $methods = $this->findMethodsFrom($extension);
 
-        // Unset by key
-        self::class::$extra_methods[$lowerClass] = array_diff_key(self::class::$extra_methods[$lowerClass], $methods);
+        if ($static) {
+            // Unset by key
+            self::class::$extra_methods[$lowerClass] = array_diff_key(self::class::$extra_methods[$lowerClass], $methods);
 
-        // Clear empty list
-        if (empty(self::class::$extra_methods[$lowerClass])) {
-            unset(self::class::$extra_methods[$lowerClass]);
+            // Clear empty list
+            if (empty(self::class::$extra_methods[$lowerClass])) {
+                unset(self::class::$extra_methods[$lowerClass]);
+            }
+        } else {
+            // Unset by key
+            $this->extraMethodsForInstance = array_diff_key($this->extraMethodsForInstance, $methods);
+
+            // Clear empty list
+            if (empty($this->extraMethodsForInstance)) {
+                unset($this->extraMethodsForInstance);
+            }
         }
     }
 
diff --git a/src/Dev/Backtrace.php b/src/Dev/Backtrace.php
index 62d402efc51..9aa7b85ad81 100644
--- a/src/Dev/Backtrace.php
+++ b/src/Dev/Backtrace.php
@@ -149,11 +149,11 @@ public static function full_func_name($item, $showArgs = false, $argCharLimit =
         if ($showArgs && isset($item['args'])) {
             $args = [];
             foreach ($item['args'] as $arg) {
-                if (!is_object($arg) || method_exists($arg, '__toString')) {
+                if (is_object($arg)) {
+                    $args[] = get_class($arg);
+                } else {
                     $sarg = is_array($arg) ? 'Array' : strval($arg);
                     $args[] = (strlen($sarg ?? '') > $argCharLimit) ? substr($sarg, 0, $argCharLimit) . '...' : $sarg;
-                } else {
-                    $args[] = get_class($arg);
                 }
             }
 
diff --git a/src/Forms/CheckboxSetField.php b/src/Forms/CheckboxSetField.php
index 6f11db35799..6386564f187 100644
--- a/src/Forms/CheckboxSetField.php
+++ b/src/Forms/CheckboxSetField.php
@@ -46,13 +46,13 @@ class CheckboxSetField extends MultiSelectField
      * @param array $properties
      * @return DBHTMLText
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $properties = array_merge($properties, [
             'Options' => $this->getOptions()
         ]);
 
-        return FormField::Field($properties);
+        return FormField::renderField($properties);
     }
 
     /**
diff --git a/src/Forms/ConfirmedPasswordField.php b/src/Forms/ConfirmedPasswordField.php
index fa61dc91a38..d990a28fa9b 100644
--- a/src/Forms/ConfirmedPasswordField.php
+++ b/src/Forms/ConfirmedPasswordField.php
@@ -195,7 +195,7 @@ public function setTitle($title)
      *
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         // Build inner content
         $fieldContent = '';
@@ -209,7 +209,7 @@ public function Field($properties = [])
                 }
             }
 
-            $fieldContent .= $field->FieldHolder(['AttributesHTML' => $this->getAttributesHTMLForChild($field)]);
+            $fieldContent .= $field->renderFieldHolder(['AttributesHTML' => $this->getAttributesHTMLForChild($field)]);
         }
 
         if (!$this->showOnClick) {
diff --git a/src/Forms/CurrencyField_Disabled.php b/src/Forms/CurrencyField_Disabled.php
index 4b26a7065d0..c5963b479a9 100644
--- a/src/Forms/CurrencyField_Disabled.php
+++ b/src/Forms/CurrencyField_Disabled.php
@@ -19,7 +19,7 @@ class CurrencyField_Disabled extends CurrencyField
      * @param array $properties
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         if ($this->value) {
             $val = Convert::raw2xml($this->value);
diff --git a/src/Forms/CurrencyField_Readonly.php b/src/Forms/CurrencyField_Readonly.php
index d9bb4037fcf..28280f18ed7 100644
--- a/src/Forms/CurrencyField_Readonly.php
+++ b/src/Forms/CurrencyField_Readonly.php
@@ -17,7 +17,7 @@ class CurrencyField_Readonly extends ReadonlyField
      * @param array $properties
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $currencySymbol = DBCurrency::config()->get('currency_symbol');
         if ($this->value) {
diff --git a/src/Forms/DatalessField.php b/src/Forms/DatalessField.php
index 0bddbc657a1..21d7a0fd1b4 100644
--- a/src/Forms/DatalessField.php
+++ b/src/Forms/DatalessField.php
@@ -42,9 +42,9 @@ public function getAttributes()
      * @param array $properties
      * @return DBHTMLText
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
-        return $this->Field($properties);
+        return $this->renderField($properties);
     }
 
     /**
@@ -54,9 +54,9 @@ public function FieldHolder($properties = [])
      * @param array $properties
      * @return DBHTMLText
      */
-    public function SmallFieldHolder($properties = [])
+    public function renderSmallFieldHolder($properties = [])
     {
-        return $this->Field($properties);
+        return $this->renderField($properties);
     }
 
     /**
diff --git a/src/Forms/DateField_Disabled.php b/src/Forms/DateField_Disabled.php
index 6bdc64f882e..113ae0bb219 100644
--- a/src/Forms/DateField_Disabled.php
+++ b/src/Forms/DateField_Disabled.php
@@ -14,7 +14,7 @@ class DateField_Disabled extends DateField
 
     protected $disabled = true;
 
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         // Default display value
         $displayValue = '<i>(' . _t('SilverStripe\\Forms\\DateField.NOTSET', 'not set') . ')</i>';
diff --git a/src/Forms/DropdownField.php b/src/Forms/DropdownField.php
index ed5da300034..2dfba72b8c3 100644
--- a/src/Forms/DropdownField.php
+++ b/src/Forms/DropdownField.php
@@ -68,7 +68,7 @@
  * DropdownField::create(
  *   'Country',
  *   'Country',
- *   singleton(MyObject::class)->dbObject('Country')->enumValues()
+ *   singleton(MyObject::class)->dbObject('Country')?->enumValues()
  * );
  * </code>
  *
@@ -128,7 +128,7 @@ public function getHasEmptyDefault()
      * @param array $properties
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $options = [];
 
@@ -141,6 +141,6 @@ public function Field($properties = [])
             'Options' => new ArrayList($options)
         ]);
 
-        return parent::Field($properties);
+        return parent::renderField($properties);
     }
 }
diff --git a/src/Forms/FieldGroup.php b/src/Forms/FieldGroup.php
index 9a0d6c67588..1a14021a78c 100644
--- a/src/Forms/FieldGroup.php
+++ b/src/Forms/FieldGroup.php
@@ -9,8 +9,8 @@
  * Lets you include a nested group of fields inside a template.
  * This control gives you more flexibility over form layout.
  *
- * Note: the child fields within a field group aren't rendered using FieldHolder().  Instead,
- * SmallFieldHolder() is called, which just prefixes $Field with a <label> tag, if the Title is set.
+ * Note: the child fields within a field group aren't rendered using renderFieldHolder().  Instead,
+ * renderSmallFieldHolder() is called, which just prefixes $Field with a <label> tag, if the Title is set.
  *
  * <b>Usage</b>
  *
@@ -154,7 +154,7 @@ public function getMessage()
         /** @var FormField $subfield */
         $messages = [];
         foreach ($dataFields as $subfield) {
-            $message = $subfield->obj('Message')->forTemplate();
+            $message = $subfield->obj('Message')?->forTemplate();
             if ($message) {
                 $messages[] = rtrim($message ?? '', ".");
             }
diff --git a/src/Forms/FieldList.php b/src/Forms/FieldList.php
index d0dc54ac822..2e7cd0ec889 100644
--- a/src/Forms/FieldList.php
+++ b/src/Forms/FieldList.php
@@ -800,13 +800,13 @@ public function fieldPosition(string|FormField $field): int|false
     }
 
     /**
-     * Default template rendering of a FieldList will concatenate all FieldHolder values.
+     * Default template rendering of a FieldList will concatenate all renderFieldHolder values.
      */
     public function forTemplate(): string
     {
         $output = "";
         foreach ($this as $field) {
-            $output .= $field->FieldHolder();
+            $output .= $field->renderFieldHolder();
         }
         return $output;
     }
diff --git a/src/Forms/FileField.php b/src/Forms/FileField.php
index 8040d1fd594..7a3153b6ea4 100644
--- a/src/Forms/FileField.php
+++ b/src/Forms/FileField.php
@@ -79,13 +79,13 @@ public function __construct($name, $title = null, $value = null)
      * @param array $properties
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $properties = array_merge($properties, [
             'MaxFileSize' => $this->getValidator()->getAllowedMaxFileSize()
         ]);
 
-        return parent::Field($properties);
+        return parent::renderField($properties);
     }
 
     public function getAttributes()
diff --git a/src/Forms/Form.php b/src/Forms/Form.php
index 7ce206f8d57..9d39615d70a 100644
--- a/src/Forms/Form.php
+++ b/src/Forms/Form.php
@@ -58,9 +58,9 @@
  * template when called through GET instead of POST.
  *
  * By appending to this URL, you can render individual form elements
- * through the {@link FormField->FieldHolder()} method.
+ * through the {@link FormField->renderFieldHolder()} method.
  * For example, the "URLSegment" field in a standard CMS form would be
- * accessible through "admin/EditForm/field/URLSegment/FieldHolder".
+ * accessible through "admin/EditForm/field/URLSegment/renderFieldHolder".
  */
 class Form extends ModelData implements HasRequestHandler
 {
diff --git a/src/Forms/FormAction.php b/src/Forms/FormAction.php
index d709ce0a0fa..f34de2078d2 100644
--- a/src/Forms/FormAction.php
+++ b/src/Forms/FormAction.php
@@ -144,7 +144,7 @@ public function setFullAction($fullAction)
      * @param array $properties
      * @return DBHTMLText
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $properties = array_merge(
             $properties,
@@ -155,16 +155,16 @@ public function Field($properties = [])
             ]
         );
 
-        return parent::Field($properties);
+        return parent::renderField($properties);
     }
 
     /**
      * @param array $properties
      * @return DBHTMLText
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
-        return $this->Field($properties);
+        return $this->renderField($properties);
     }
 
     public function Type()
diff --git a/src/Forms/FormField.php b/src/Forms/FormField.php
index 0d210436b0f..69206ef5760 100644
--- a/src/Forms/FormField.php
+++ b/src/Forms/FormField.php
@@ -15,6 +15,7 @@
 use SilverStripe\View\AttributesHTML;
 use SilverStripe\View\SSViewer;
 use SilverStripe\Model\ModelData;
+use SilverStripe\ORM\DataObject;
 
 /**
  * Represents a field in a form.
@@ -260,9 +261,9 @@ class FormField extends RequestHandler
     protected $schemaData = [];
 
     private static $casting = [
-        'FieldHolder' => 'HTMLFragment',
-        'SmallFieldHolder' => 'HTMLFragment',
-        'Field' => 'HTMLFragment',
+        'renderFieldHolder' => 'HTMLFragment',
+        'renderSmallFieldHolder' => 'HTMLFragment',
+        'renderField' => 'HTMLFragment',
         'AttributesHTML' => 'HTMLFragment', // property $AttributesHTML version
         'getAttributesHTML' => 'HTMLFragment', // method $getAttributesHTML($arg) version
         'Value' => 'Text',
@@ -458,7 +459,7 @@ public function Value()
      *
      * By default, makes use of $this->dataValue()
      *
-     * @param ModelData|DataObjectInterface $record Record to save data into
+     * @param DataObjectInterface $record Record to save data into
      */
     public function saveInto(DataObjectInterface $record)
     {
@@ -469,7 +470,9 @@ public function saveInto(DataObjectInterface $record)
         if (($pos = strrpos($this->name ?? '', '.')) !== false) {
             $relation = substr($this->name ?? '', 0, $pos);
             $fieldName = substr($this->name ?? '', $pos + 1);
-            $component = $record->relObject($relation);
+            if ($record instanceof DataObject) {
+                $component = $record->relObject($relation);
+            }
         }
 
         if ($fieldName && $component) {
@@ -584,7 +587,7 @@ public function extraClass()
         // Allow custom styling of any element in the container based on validation errors,
         // e.g. red borders on input tags.
         //
-        // CSS class needs to be different from the one rendered through {@link FieldHolder()}.
+        // CSS class needs to be different from the one rendered through {@link renderFieldHolder()}.
         if ($this->getMessage()) {
             $classes[] = 'holder-' . $this->getMessageType();
         }
@@ -914,7 +917,7 @@ public function setSmallFieldHolderTemplate($smallFieldHolderTemplate)
      * @param array $properties
      * @return DBHTMLText
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $context = $this;
 
@@ -949,7 +952,7 @@ public function Field($properties = [])
      *
      * @return DBHTMLText
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
         $context = $this;
 
@@ -969,7 +972,7 @@ public function FieldHolder($properties = [])
      *
      * @return string
      */
-    public function SmallFieldHolder($properties = [])
+    public function renderSmallFieldHolder($properties = [])
     {
         $context = $this;
 
@@ -1289,7 +1292,7 @@ public function debug(): string
      */
     public function forTemplate(): string
     {
-        return $this->Field();
+        return $this->renderField();
     }
 
     /**
@@ -1469,12 +1472,12 @@ public function getSchemaDataDefaults()
             'schemaType' => $this->getSchemaDataType(),
             'component' => $this->getSchemaComponent(),
             'holderId' => $this->HolderID(),
-            'title' => $this->obj('Title')->getSchemaValue(),
+            'title' => $this->obj('Title')?->getSchemaValue(),
             'source' => null,
             'extraClass' => $this->extraClass(),
-            'description' => $this->obj('Description')->getSchemaValue(),
-            'rightTitle' => $this->obj('RightTitle')->getSchemaValue(),
-            'leftTitle' => $this->obj('LeftTitle')->getSchemaValue(),
+            'description' => $this->obj('Description')?->getSchemaValue(),
+            'rightTitle' => $this->obj('RightTitle')?->getSchemaValue(),
+            'leftTitle' => $this->obj('LeftTitle')?->getSchemaValue(),
             'readOnly' => $this->isReadonly(),
             'disabled' => $this->isDisabled(),
             'customValidationMessage' => $this->getCustomValidationMessage(),
diff --git a/src/Forms/FormScaffolder.php b/src/Forms/FormScaffolder.php
index 099dabf5d6e..db43a88e88d 100644
--- a/src/Forms/FormScaffolder.php
+++ b/src/Forms/FormScaffolder.php
@@ -115,7 +115,7 @@ public function getFieldList()
                 $fieldObject = $this
                     ->obj
                     ->dbObject($fieldName)
-                    ->scaffoldFormField(null, $this->getParamsArray());
+                    ?->scaffoldFormField(null, $this->getParamsArray());
             }
             // Allow fields to opt-out of scaffolding
             if (!$fieldObject) {
@@ -145,7 +145,7 @@ public function getFieldList()
                     $fieldClass = $this->fieldClasses[$fieldName];
                     $hasOneField = new $fieldClass($fieldName);
                 } else {
-                    $hasOneField = $this->obj->dbObject($fieldName)->scaffoldFormField(null, $this->getParamsArray());
+                    $hasOneField = $this->obj->dbObject($fieldName)?->scaffoldFormField(null, $this->getParamsArray());
                 }
                 if (empty($hasOneField)) {
                     continue; // Allow fields to opt out of scaffolding
diff --git a/src/Forms/GridField/GridField.php b/src/Forms/GridField/GridField.php
index 12b2522c087..9e3dba8a0b0 100644
--- a/src/Forms/GridField/GridField.php
+++ b/src/Forms/GridField/GridField.php
@@ -528,7 +528,7 @@ public function addAllStateToUrl(string $link): string
      * @param array $properties
      * @return string
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
         $this->extend('onBeforeRenderHolder', $this, $properties);
 
@@ -852,10 +852,10 @@ protected function newRowClasses($total, $index, $record)
      * @param array $properties
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $this->extend('onBeforeRender', $this);
-        return $this->FieldHolder($properties);
+        return $this->renderFieldHolder($properties);
     }
 
     /**
@@ -1160,7 +1160,7 @@ public function gridFieldAlterAction($data, $form, HTTPRequest $request)
             if ($this->getState()->Readonly === true) {
                 $this->performDisabledTransformation();
             }
-            return $this->FieldHolder();
+            return $this->renderFieldHolder();
         }
 
         return $form->forTemplate();
diff --git a/src/Forms/GridField/GridFieldDeleteAction.php b/src/Forms/GridField/GridFieldDeleteAction.php
index dd9ca689eff..884d5c2f111 100644
--- a/src/Forms/GridField/GridFieldDeleteAction.php
+++ b/src/Forms/GridField/GridFieldDeleteAction.php
@@ -164,7 +164,7 @@ public function getColumnContent($gridField, $record, $columnName)
         $field = $this->getRemoveAction($gridField, $record, $columnName);
 
         if ($field) {
-            return $field->Field();
+            return $field->renderField();
         }
 
         return null;
diff --git a/src/Forms/GridField/GridFieldExportButton.php b/src/Forms/GridField/GridFieldExportButton.php
index 6b543b8c49e..0fb2361f314 100644
--- a/src/Forms/GridField/GridFieldExportButton.php
+++ b/src/Forms/GridField/GridFieldExportButton.php
@@ -80,7 +80,7 @@ public function getHTMLFragments($gridField)
         $button->addExtraClass('btn btn-secondary no-ajax font-icon-down-circled action_export');
         $button->setForm($gridField->getForm());
         return [
-            $this->targetFragment => $button->Field(),
+            $this->targetFragment => $button->renderField(),
         ];
     }
 
diff --git a/src/Forms/GridField/GridFieldImportButton.php b/src/Forms/GridField/GridFieldImportButton.php
index 4f0ba641ae5..a1e5e7b7d1a 100644
--- a/src/Forms/GridField/GridFieldImportButton.php
+++ b/src/Forms/GridField/GridFieldImportButton.php
@@ -86,7 +86,7 @@ public function getHTMLFragments($gridField)
         }
 
         return [
-            $this->targetFragment => $button->Field()
+            $this->targetFragment => $button->renderField()
         ];
     }
 
diff --git a/src/Forms/GridField/GridFieldPrintButton.php b/src/Forms/GridField/GridFieldPrintButton.php
index bebc63d65a6..6e892e17ee4 100644
--- a/src/Forms/GridField/GridFieldPrintButton.php
+++ b/src/Forms/GridField/GridFieldPrintButton.php
@@ -72,7 +72,7 @@ public function getHTMLFragments($gridField)
         $button->addExtraClass('font-icon-print grid-print-button btn btn-secondary');
 
         return [
-            $this->targetFragment =>  $button->Field(),
+            $this->targetFragment =>  $button->renderField(),
         ];
     }
 
diff --git a/src/Forms/GridField/GridState_Component.php b/src/Forms/GridField/GridState_Component.php
index b1f67272f3b..5732a07528c 100644
--- a/src/Forms/GridField/GridState_Component.php
+++ b/src/Forms/GridField/GridState_Component.php
@@ -11,7 +11,7 @@ class GridState_Component extends AbstractGridFieldComponent implements GridFiel
     public function getHTMLFragments($gridField)
     {
         return [
-            'before' => $gridField->getState(false)->Field()
+            'before' => $gridField->getState(false)->renderField()
         ];
     }
 }
diff --git a/src/Forms/HTMLEditor/HTMLEditorField.php b/src/Forms/HTMLEditor/HTMLEditorField.php
index 90c3fad75c1..2e8e9d346d9 100644
--- a/src/Forms/HTMLEditor/HTMLEditorField.php
+++ b/src/Forms/HTMLEditor/HTMLEditorField.php
@@ -5,9 +5,11 @@
 use SilverStripe\Assets\Shortcodes\ImageShortcodeProvider;
 use SilverStripe\Forms\FormField;
 use SilverStripe\Forms\TextareaField;
-use SilverStripe\ORM\DataObject;
 use SilverStripe\ORM\DataObjectInterface;
 use Exception;
+use SilverStripe\Model\ModelData;
+use SilverStripe\ORM\FieldType\DBField;
+use SilverStripe\View\CastingService;
 use SilverStripe\View\Parsers\HTMLValue;
 
 /**
@@ -123,13 +125,9 @@ public function getAttributes()
         );
     }
 
-    /**
-     * @param DataObject|DataObjectInterface $record
-     * @throws Exception
-     */
     public function saveInto(DataObjectInterface $record)
     {
-        if ($record->hasField($this->name) && $record->escapeTypeForField($this->name) != 'xml') {
+        if (!$this->usesXmlFriendlyField($record)) {
             throw new Exception(
                 'HTMLEditorField->saveInto(): This field should save into a HTMLText or HTMLVarchar field.'
             );
@@ -170,11 +168,11 @@ public function performDisabledTransformation()
         return $this->performReadonlyTransformation();
     }
 
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         // Include requirements
         $this->getEditorConfig()->init();
-        return parent::Field($properties);
+        return parent::renderField($properties);
     }
 
     public function getSchemaStateDefaults()
@@ -225,4 +223,15 @@ private function setEditorHeight(HTMLEditorConfig $config): HTMLEditorConfig
 
         return $config;
     }
+
+    private function usesXmlFriendlyField(DataObjectInterface $record): bool
+    {
+        if ($record instanceof ModelData && !$record->hasField($this->getName())) {
+            return true;
+        }
+
+        $castingService = CastingService::singleton();
+        $castValue = $castingService->cast($this->Value(), $record, $this->getName());
+        return $castValue instanceof DBField && $castValue::config()->get('escape_type') === 'xml';
+    }
 }
diff --git a/src/Forms/HTMLReadonlyField.php b/src/Forms/HTMLReadonlyField.php
index 64bb339e30f..5245fcd5384 100644
--- a/src/Forms/HTMLReadonlyField.php
+++ b/src/Forms/HTMLReadonlyField.php
@@ -21,7 +21,7 @@ class HTMLReadonlyField extends ReadonlyField
      */
     protected $schemaComponent = 'HtmlReadonlyField';
 
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         return $this->renderWith($this->getTemplates());
     }
diff --git a/src/Forms/HiddenField.php b/src/Forms/HiddenField.php
index 3c5ce588960..d18d61e5099 100644
--- a/src/Forms/HiddenField.php
+++ b/src/Forms/HiddenField.php
@@ -16,9 +16,9 @@ class HiddenField extends FormField
      * @param array $properties
      * @return string
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
-        return $this->Field($properties);
+        return $this->renderField($properties);
     }
 
     /**
@@ -41,8 +41,8 @@ public function IsHidden()
         return true;
     }
 
-    function SmallFieldHolder($properties = [])
+    function renderSmallFieldHolder($properties = [])
     {
-        return $this->FieldHolder($properties);
+        return $this->renderFieldHolder($properties);
     }
 }
diff --git a/src/Forms/ListboxField.php b/src/Forms/ListboxField.php
index 5ff18afff0c..6f2599bc45e 100644
--- a/src/Forms/ListboxField.php
+++ b/src/Forms/ListboxField.php
@@ -72,13 +72,13 @@ public function __construct($name, $title = '', $source = [], $value = null, $si
      * @param array $properties
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $properties = array_merge($properties, [
             'Options' => $this->getOptions(),
         ]);
 
-        return FormField::Field($properties);
+        return FormField::renderField($properties);
     }
 
     /**
diff --git a/src/Forms/LiteralField.php b/src/Forms/LiteralField.php
index 0dda550c0c3..5edce17a4e2 100644
--- a/src/Forms/LiteralField.php
+++ b/src/Forms/LiteralField.php
@@ -49,7 +49,7 @@ public function __construct($name, $content)
      *
      * @return string
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
         if ($this->content instanceof ModelData) {
             $context = $this->content;
@@ -69,9 +69,9 @@ public function FieldHolder($properties = [])
      *
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
-        return $this->FieldHolder($properties);
+        return $this->renderFieldHolder($properties);
     }
 
     /**
@@ -130,7 +130,7 @@ public function performReadonlyTransformation()
     public function getSchemaStateDefaults()
     {
         $state = parent::getSchemaStateDefaults();
-        $state['value'] = $this->FieldHolder();
+        $state['value'] = $this->renderFieldHolder();
 
         return $state;
     }
diff --git a/src/Forms/LookupField.php b/src/Forms/LookupField.php
index ac388fc394b..02af08cdde2 100644
--- a/src/Forms/LookupField.php
+++ b/src/Forms/LookupField.php
@@ -29,7 +29,7 @@ class LookupField extends MultiSelectField
      *
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $source = ArrayLib::flatten($this->getSource());
         $values = $this->getValueArray();
@@ -62,7 +62,7 @@ public function Field($properties = [])
             'InputValue' => $inputValue
         ]);
 
-        return parent::Field($properties);
+        return parent::renderField($properties);
     }
 
     /**
diff --git a/src/Forms/NullableField.php b/src/Forms/NullableField.php
index 99669cd0ab8..0fd99e454c1 100644
--- a/src/Forms/NullableField.php
+++ b/src/Forms/NullableField.php
@@ -108,7 +108,7 @@ public function getIsNullId()
      *
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         if ($this->isReadonly()) {
             $nullableCheckbox = new CheckboxField_Readonly($this->getIsNullId());
@@ -120,8 +120,8 @@ public function Field($properties = [])
 
         return sprintf(
             '%s %s&nbsp;<span>%s</span>',
-            $this->valueField->Field(),
-            $nullableCheckbox->Field(),
+            $this->valueField->renderField(),
+            $nullableCheckbox->renderField(),
             $this->getIsNullLabel()
         );
     }
diff --git a/src/Forms/OptionsetField.php b/src/Forms/OptionsetField.php
index 72655646c36..52222334198 100644
--- a/src/Forms/OptionsetField.php
+++ b/src/Forms/OptionsetField.php
@@ -116,7 +116,7 @@ protected function getOptionClass($value, $odd)
     }
 
 
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $options = [];
         $odd = false;
@@ -131,7 +131,7 @@ public function Field($properties = [])
             'Options' => new ArrayList($options)
         ]);
 
-        return FormField::Field($properties);
+        return FormField::renderField($properties);
     }
 
     /**
diff --git a/src/Forms/PrintableTransformation_TabSet.php b/src/Forms/PrintableTransformation_TabSet.php
index a457e7d0172..c61541cdeca 100644
--- a/src/Forms/PrintableTransformation_TabSet.php
+++ b/src/Forms/PrintableTransformation_TabSet.php
@@ -16,14 +16,14 @@ public function __construct($tabs)
         CompositeField::__construct($tabs);
     }
 
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
         // This gives us support for sub-tabs.
         $tag = $this->getTabSet() ? 'h2>' : 'h1>';
         $retVal = '';
         foreach ($this->getChildren() as $tab) {
             $retVal .= "<$tag" . $tab->Title() . "</$tag\n";
-            $retVal .= $tab->FieldHolder();
+            $retVal .= $tab->renderFieldHolder();
         }
         return $retVal;
     }
diff --git a/src/Forms/SearchableDropdownTrait.php b/src/Forms/SearchableDropdownTrait.php
index fa751c49a2f..2fc38b8609d 100644
--- a/src/Forms/SearchableDropdownTrait.php
+++ b/src/Forms/SearchableDropdownTrait.php
@@ -265,7 +265,7 @@ public function getSource(): array
         return $this->getListMap($this->sourceList);
     }
 
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $context = $this;
         $this->extend('onBeforeRender', $context, $properties);
diff --git a/src/Forms/SelectionGroup.php b/src/Forms/SelectionGroup.php
index d814960f6bb..ead78a7c1d8 100644
--- a/src/Forms/SelectionGroup.php
+++ b/src/Forms/SelectionGroup.php
@@ -117,8 +117,8 @@ public function hasData()
         return true;
     }
 
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
-        return parent::FieldHolder($properties);
+        return parent::renderFieldHolder($properties);
     }
 }
diff --git a/src/Forms/SingleLookupField.php b/src/Forms/SingleLookupField.php
index 5590574caa1..01d9a09a44f 100644
--- a/src/Forms/SingleLookupField.php
+++ b/src/Forms/SingleLookupField.php
@@ -113,7 +113,7 @@ public function getTemplate()
      *
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $label = $this->valueToLabel();
         if (!is_null($label)) {
@@ -129,6 +129,6 @@ public function Field($properties = [])
             'InputValue' => $inputValue
         ]);
 
-        return parent::Field($properties);
+        return parent::renderField($properties);
     }
 }
diff --git a/src/Forms/TabSet.php b/src/Forms/TabSet.php
index 47037193e7a..ec9ba47613c 100644
--- a/src/Forms/TabSet.php
+++ b/src/Forms/TabSet.php
@@ -129,7 +129,7 @@ public function setID($id)
      * @param array $properties
      * @return DBHTMLText|string
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
         $obj = $properties ? $this->customise($properties) : $this;
 
diff --git a/src/Forms/ToggleCompositeField.php b/src/Forms/ToggleCompositeField.php
index 52e421e0c5c..a3de4edc9a0 100644
--- a/src/Forms/ToggleCompositeField.php
+++ b/src/Forms/ToggleCompositeField.php
@@ -42,7 +42,7 @@ public function __construct($name, $title, $children)
      * @param array $properties
      * @return string
      */
-    public function FieldHolder($properties = [])
+    public function renderFieldHolder($properties = [])
     {
         $context = $this;
 
diff --git a/src/Forms/TreeDropdownField.php b/src/Forms/TreeDropdownField.php
index c503c591aa3..1019736ff36 100644
--- a/src/Forms/TreeDropdownField.php
+++ b/src/Forms/TreeDropdownField.php
@@ -870,14 +870,14 @@ public function getSchemaStateDefaults()
                 $ancestors = $record->getAncestors(true)->reverse();
 
                 foreach ($ancestors as $parent) {
-                    $title = $parent->obj($this->getTitleField())->getValue();
+                    $title = $parent->obj($this->getTitleField())?->getValue();
                     $titlePath .= $title . '/';
                 }
             }
             $data['data']['valueObject'] = [
-                'id' => $record->obj($this->getKeyField())->getValue(),
-                'title' => $record->obj($this->getTitleField())->getValue(),
-                'treetitle' => $record->obj($this->getLabelField())->getSchemaValue(),
+                'id' => $record->obj($this->getKeyField())?->getValue(),
+                'title' => $record->obj($this->getTitleField())?->getValue(),
+                'treetitle' => $record->obj($this->getLabelField())?->getSchemaValue(),
                 'titlePath' => $titlePath,
             ];
         }
diff --git a/src/Forms/TreeDropdownField_Readonly.php b/src/Forms/TreeDropdownField_Readonly.php
index d54b1736538..67e748de0db 100644
--- a/src/Forms/TreeDropdownField_Readonly.php
+++ b/src/Forms/TreeDropdownField_Readonly.php
@@ -6,7 +6,7 @@ class TreeDropdownField_Readonly extends TreeDropdownField
 {
     protected $readonly = true;
 
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $fieldName = $this->getTitleField();
         if ($this->value) {
@@ -20,6 +20,6 @@ public function Field($properties = [])
         $field = LookupField::create($this->name, $this->title, $source);
         $field->setValue($this->value);
         $field->setForm($this->form);
-        return $field->Field();
+        return $field->renderField();
     }
 }
diff --git a/src/Forms/TreeMultiselectField.php b/src/Forms/TreeMultiselectField.php
index a1362f24715..9d624c2355f 100644
--- a/src/Forms/TreeMultiselectField.php
+++ b/src/Forms/TreeMultiselectField.php
@@ -92,10 +92,10 @@ public function getSchemaStateDefaults()
         foreach ($items as $item) {
             if ($item instanceof DataObject) {
                 $values[] = [
-                    'id' => $item->obj($this->getKeyField())->getValue(),
-                    'title' => $item->obj($this->getTitleField())->getValue(),
+                    'id' => $item->obj($this->getKeyField())?->getValue(),
+                    'title' => $item->obj($this->getTitleField())?->getValue(),
                     'parentid' => $item->ParentID,
-                    'treetitle' => $item->obj($this->getLabelField())->getSchemaValue(),
+                    'treetitle' => $item->obj($this->getLabelField())?->getSchemaValue(),
                 ];
             } else {
                 $values[] = $item;
@@ -200,7 +200,7 @@ public function dataValue()
      * @param array $properties
      * @return DBHTMLText
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $value = '';
         $titleArray = [];
@@ -212,7 +212,7 @@ public function Field($properties = [])
             foreach ($items as $item) {
                 $idArray[] = $item->ID;
                 $titleArray[] = ($item instanceof ModelData)
-                    ? $item->obj($this->getLabelField())->forTemplate()
+                    ? $item->obj($this->getLabelField())?->forTemplate()
                     : Convert::raw2xml($item->{$this->getLabelField()});
             }
 
@@ -239,7 +239,7 @@ public function Field($properties = [])
                 'Value' => $value
             ]
         );
-        return FormField::Field($properties);
+        return FormField::renderField($properties);
     }
 
     /**
diff --git a/src/Forms/TreeMultiselectField_Readonly.php b/src/Forms/TreeMultiselectField_Readonly.php
index 65d23b17c16..ca979f948e9 100644
--- a/src/Forms/TreeMultiselectField_Readonly.php
+++ b/src/Forms/TreeMultiselectField_Readonly.php
@@ -7,7 +7,7 @@ class TreeMultiselectField_Readonly extends TreeMultiselectField
 
     protected $readonly = true;
 
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         // Build list of titles
         $titleField = $this->getTitleField();
@@ -35,6 +35,6 @@ public function Field($properties = [])
         $valueField->setValue($itemIDsList);
         $valueField->setForm($this->form);
 
-        return $field->Field() . $valueField->Field();
+        return $field->renderField() . $valueField->renderField();
     }
 }
diff --git a/src/Model/List/ListDecorator.php b/src/Model/List/ListDecorator.php
index 6cfc963b425..fa3c43dae8b 100644
--- a/src/Model/List/ListDecorator.php
+++ b/src/Model/List/ListDecorator.php
@@ -56,7 +56,9 @@ public function getList(): SS_List&Sortable&Filterable&Limitable
     public function setList(SS_List&Sortable&Filterable&Limitable $list): ListDecorator
     {
         $this->list = $list;
-        $this->failover = $this->list;
+        if ($list instanceof ModelData) {
+            $this->setFailover($list);
+        }
         return $this;
     }
 
diff --git a/src/Model/ModelData.php b/src/Model/ModelData.php
index 04d5a1fc027..8eff38e2b3a 100644
--- a/src/Model/ModelData.php
+++ b/src/Model/ModelData.php
@@ -7,19 +7,22 @@
 use LogicException;
 use ReflectionMethod;
 use ReflectionProperty;
+use SilverStripe\Control\RSS\RSSFeed;
+use SilverStripe\Control\RSS\RSSFeed_Entry;
+use SilverStripe\Control\Tests\RSS\RSSFeedTest\ItemB;
 use SilverStripe\Core\ClassInfo;
 use SilverStripe\Core\Config\Configurable;
 use SilverStripe\Core\Convert;
 use SilverStripe\Core\Extensible;
 use SilverStripe\Core\Injector\Injectable;
-use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Dev\Debug;
 use SilverStripe\Core\ArrayLib;
-use SilverStripe\Model\List\ArrayList;
 use SilverStripe\ORM\FieldType\DBField;
 use SilverStripe\ORM\FieldType\DBHTMLText;
 use SilverStripe\Model\ArrayData;
+use SilverStripe\View\CastingService;
 use SilverStripe\View\SSViewer;
+use Stringable;
 use UnexpectedValueException;
 
 /**
@@ -29,7 +32,7 @@
  * is provided and automatically escaped by ModelData. Any class that needs to be available to a view (controllers,
  * {@link DataObject}s, page controls) should inherit from this class.
  */
-class ModelData
+class ModelData implements Stringable
 {
     use Extensible {
         defineMethods as extensibleDefineMethods;
@@ -38,7 +41,7 @@ class ModelData
     use Configurable;
 
     /**
-     * An array of objects to cast certain fields to. This is set up as an array in the format:
+     * An array of DBField classes to cast certain fields to. This is set up as an array in the format:
      *
      * <code>
      * public static $casting = array (
@@ -47,16 +50,18 @@ class ModelData
      * </code>
      */
     private static array $casting = [
-        'CSSClasses' => 'Varchar'
+        'CSSClasses' => 'Varchar',
+        'forTemplate' => 'HTMLText',
     ];
 
     /**
-     * The default object to cast scalar fields to if casting information is not specified, and casting to an object
+     * The default class to cast scalar fields to if casting information is not specified, and casting to an object
      * is required.
+     * This can be any injectable service name but must resolve to a DBField subclass.
+     *
+     * If null, casting will be determined based on the type of value (e.g. integers will be cast to DBInt)
      */
-    private static string $default_cast = 'Text';
-
-    private static array $casting_cache = [];
+    private static ?string $default_cast = null;
 
     /**
      * Acts as a PHP 8.2+ compliant replacement for dynamic properties
@@ -251,8 +256,7 @@ private function isAccessibleProperty(string $property): bool
     // -----------------------------------------------------------------------------------------------------------------
 
     /**
-     * Add methods from the {@link ModelData::$failover} object, as well as wrapping any methods prefixed with an
-     * underscore into a {@link ModelData::cachedCall()}.
+     * Add methods from the {@link ModelData::$failover} object
      *
      * @throws LogicException
      */
@@ -262,7 +266,7 @@ public function defineMethods()
             throw new LogicException("ModelData::\$failover set to a non-object");
         }
         if ($this->failover) {
-            $this->addMethodsFrom('failover');
+            $this->addMethodsFrom('failover', static: false);
 
             if (isset($_REQUEST['debugfailover'])) {
                 $class = static::class;
@@ -305,12 +309,18 @@ public function exists(): bool
         return true;
     }
 
+    public function __toString(): string
+    {
+        return $this->forTemplate();
+    }
+
     /**
-     * Return the class name (though subclasses may return something else)
+     * Return the HTML markup that represents this model when it is directly injected into a template (e.g. using $Me).
+     * By default this attempts to render the model using templates based on the class hierarchy.
      */
-    public function __toString(): string
+    public function forTemplate(): string
     {
-        return static::class;
+        return $this->renderWith($this->getViewerTemplates());
     }
 
     public function getCustomisedObj(): ?ModelData
@@ -326,14 +336,10 @@ public function setCustomisedObj(ModelData $object)
     // CASTING ---------------------------------------------------------------------------------------------------------
 
     /**
-     * Return the "casting helper" (a piece of PHP code that when evaluated creates a casted value object)
+     * Return the "casting helper" (an injectable service name)
      * for a field on this object. This helper will be a subclass of DBField.
-     *
-     * @param bool $useFallback If true, fall back on the default casting helper if there isn't an explicit one.
-     * @return string|null Casting helper As a constructor pattern, and may include arguments.
-     * @throws Exception
      */
-    public function castingHelper(string $field, bool $useFallback = true): ?string
+    public function castingHelper(string $field): ?string
     {
         // Get casting if it has been configured.
         // DB fields and PHP methods are all case insensitive so we normalise casing before checking.
@@ -346,67 +352,15 @@ public function castingHelper(string $field, bool $useFallback = true): ?string
         // If no specific cast is declared, fall back to failover.
         $failover = $this->getFailover();
         if ($failover) {
-            $cast = $failover->castingHelper($field, $useFallback);
+            $cast = $failover->castingHelper($field);
             if ($cast) {
                 return $cast;
             }
         }
 
-        if ($useFallback) {
-            return $this->defaultCastingHelper($field);
-        }
-
         return null;
     }
 
-    /**
-     * Return the default "casting helper" for use when no explicit casting helper is defined.
-     * This helper will be a subclass of DBField. See castingHelper()
-     */
-    protected function defaultCastingHelper(string $field): string
-    {
-        // If there is a failover, the default_cast will always
-        // be drawn from this object instead of the top level object.
-        $failover = $this->getFailover();
-        if ($failover) {
-            $cast = $failover->defaultCastingHelper($field);
-            if ($cast) {
-                return $cast;
-            }
-        }
-
-        // Fall back to raw default_cast
-        $default = $this->config()->get('default_cast');
-        if (empty($default)) {
-            throw new Exception('No default_cast');
-        }
-        return $default;
-    }
-
-    /**
-     * Get the class name a field on this object will be casted to.
-     */
-    public function castingClass(string $field): string
-    {
-        // Strip arguments
-        $spec = $this->castingHelper($field);
-        return trim(strtok($spec ?? '', '(') ?? '');
-    }
-
-    /**
-     * Return the string-format type for the given field.
-     *
-     * @return string 'xml'|'raw'
-     */
-    public function escapeTypeForField(string $field): string
-    {
-        $class = $this->castingClass($field) ?: $this->config()->get('default_cast');
-
-        /** @var DBField $type */
-        $type = Injector::inst()->get($class, true);
-        return $type->config()->get('escape_type');
-    }
-
     // TEMPLATE ACCESS LAYER -------------------------------------------------------------------------------------------
 
     /**
@@ -440,27 +394,11 @@ public function renderWith($template, ModelData|array|null $customFields = null)
     }
 
     /**
-     * Generate the cache name for a field
-     *
-     * @param string $fieldName Name of field
-     * @param array $arguments List of optional arguments given
-     * @return string
-     */
-    protected function objCacheName($fieldName, $arguments)
-    {
-        return $arguments
-            ? $fieldName . ":" . var_export($arguments, true)
-            : $fieldName;
-    }
-
-    /**
-     * Get a cached value from the field cache
-     *
-     * @param string $key Cache key
-     * @return mixed
+     * Get a cached value from the field cache for a field
      */
-    protected function objCacheGet($key)
+    public function objCacheGet(string $fieldName, array $arguments = []): mixed
     {
+        $key = $this->objCacheName($fieldName, $arguments);
         if (isset($this->objCache[$key])) {
             return $this->objCache[$key];
         }
@@ -468,14 +406,11 @@ protected function objCacheGet($key)
     }
 
     /**
-     * Store a value in the field cache
-     *
-     * @param string $key Cache key
-     * @param mixed $value
-     * @return $this
+     * Store a value in the field cache for a field
      */
-    protected function objCacheSet($key, $value)
+    public function objCacheSet(string $fieldName, array $arguments, mixed $value): static
     {
+        $key = $this->objCacheName($fieldName, $arguments);
         $this->objCache[$key] = $value;
         return $this;
     }
@@ -485,7 +420,7 @@ protected function objCacheSet($key, $value)
      *
      * @return $this
      */
-    protected function objCacheClear()
+    public function objCacheClear()
     {
         $this->objCache = [];
         return $this;
@@ -497,82 +432,46 @@ protected function objCacheClear()
      *
      * @return object|DBField|null The specific object representing the field, or null if there is no
      * property, method, or dynamic data available for that field.
-     * Note that if there is a property or method that returns null, a relevant DBField instance will
-     * be returned.
      */
     public function obj(
         string $fieldName,
         array $arguments = [],
-        bool $cache = false,
-        ?string $cacheName = null
+        bool $cache = false
     ): ?object {
-        $hasObj = false;
-        if (!$cacheName && $cache) {
-            $cacheName = $this->objCacheName($fieldName, $arguments);
-        }
-
         // Check pre-cached value
-        $value = $cache ? $this->objCacheGet($cacheName) : null;
-        if ($value !== null) {
-            return $value;
-        }
-
-        // Load value from record
-        if ($this->hasMethod($fieldName)) {
-            $hasObj = true;
-            $value = call_user_func_array([$this, $fieldName], $arguments ?: []);
-        } else {
-            $hasObj = $this->hasField($fieldName) || ($this->hasMethod("get{$fieldName}") && $this->isAccessibleMethod("get{$fieldName}"));
-            $value = $this->$fieldName;
-        }
-
-        // Return null early if there's no backing for this field
-        // i.e. no poperty, no method, etc - it just doesn't exist on this model.
-        if (!$hasObj && $value === null) {
-            return null;
-        }
-
-        // Try to cast object if we have an explicit cast set
-        if (!is_object($value)) {
-            $castingHelper = $this->castingHelper($fieldName, false);
-            if ($castingHelper !== null) {
-                $valueObject = Injector::inst()->create($castingHelper, $fieldName);
-                $valueObject->setValue($value, $this);
-                $value = $valueObject;
+        $value = $cache ? $this->objCacheGet($fieldName, $arguments) : null;
+        if ($value === null) {
+            $hasObj = false;
+            // Load value from record
+            $getter = "get{$fieldName}";
+            $hasGetter = $this->hasMethod($getter) && $this->isAccessibleMethod($getter);
+            if ($hasGetter || $this->hasField($fieldName)) {
+                $hasObj = true;
+                if (!empty($arguments) && $hasGetter) {
+                    $value = call_user_func_array([$this, $getter], $arguments);
+                } else {
+                    // __get() uses the getter if there is one, so just rely on it
+                    // to get the value correctly
+                    $value = $this->$fieldName;
+                }
+            } elseif ($this->hasMethod($fieldName)) {
+                $hasObj = true;
+                $value = call_user_func_array([$this, $fieldName], $arguments ?: []);
             }
-        }
-
-        // Wrap list arrays in ModelData so templates can handle them
-        if (is_array($value) && array_is_list($value)) {
-            $value = ArrayList::create($value);
-        }
 
-        // Fallback on default casting
-        if (!is_object($value)) {
-            // Force cast
-            $castingHelper = $this->defaultCastingHelper($fieldName);
-            $valueObject = Injector::inst()->create($castingHelper, $fieldName);
-            $valueObject->setValue($value, $this);
-            $value = $valueObject;
-        }
+            // Record in cache
+            if ($value && $cache) {
+                $this->objCacheSet($fieldName, $arguments, $value);
+            }
 
-        // Record in cache
-        if ($cache) {
-            $this->objCacheSet($cacheName, $value);
+            // Return null early if there's no backing for this field
+            // i.e. no poperty, no method, etc - it just doesn't exist on this model.
+            if (!$hasObj && $value === null) {
+                return null;
+            }
         }
 
-        return $value;
-    }
-
-    /**
-     * A simple wrapper around {@link ModelData::obj()} that automatically caches the result so it can be used again
-     * without re-running the method.
-     *
-     * @return Object|DBField
-     */
-    public function cachedCall(string $fieldName, array $arguments = [], ?string $cacheName = null): object
-    {
-        return $this->obj($fieldName, $arguments, true, $cacheName);
+        return CastingService::singleton()->cast($value, $this, $fieldName, true);
     }
 
     /**
@@ -677,4 +576,14 @@ public function Debug(): ModelData|string
     {
         return ModelDataDebugger::create($this);
     }
+
+    /**
+     * Generate the cache name for a field
+     */
+    private function objCacheName(string $fieldName, array $arguments = []): string
+    {
+        return empty($arguments)
+            ? $fieldName
+            : $fieldName . ":" . var_export($arguments, true);
+    }
 }
diff --git a/src/Model/ModelDataCustomised.php b/src/Model/ModelDataCustomised.php
index 6ae73be21ac..1ca66d6560a 100644
--- a/src/Model/ModelDataCustomised.php
+++ b/src/Model/ModelDataCustomised.php
@@ -49,17 +49,22 @@ public function __isset(string $property): bool
         return isset($this->customised->$property) || isset($this->original->$property) || parent::__isset($property);
     }
 
+    public function forTemplate(): string
+    {
+        return $this->original->forTemplate();
+    }
+
     public function hasMethod($method)
     {
         return $this->customised->hasMethod($method) || $this->original->hasMethod($method);
     }
 
-    public function cachedCall(string $fieldName, array $arguments = [], ?string $cacheName = null): object
+    public function castingHelper(string $field): ?string
     {
-        if ($this->customisedHas($fieldName)) {
-            return $this->customised->cachedCall($fieldName, $arguments, $cacheName);
+        if ($this->customisedHas($field)) {
+            return $this->customised->castingHelper($field);
         }
-        return $this->original->cachedCall($fieldName, $arguments, $cacheName);
+        return $this->original->castingHelper($field);
     }
 
     public function obj(
diff --git a/src/ORM/DataList.php b/src/ORM/DataList.php
index d703d3b9050..e8d69f27f2e 100644
--- a/src/ORM/DataList.php
+++ b/src/ORM/DataList.php
@@ -19,6 +19,7 @@
 use SilverStripe\Model\List\Map;
 use SilverStripe\Model\List\Sortable;
 use SilverStripe\Model\List\SS_List;
+use SilverStripe\ORM\FieldType\DBField;
 use SilverStripe\ORM\Filters\SearchFilterable;
 
 /**
@@ -1852,7 +1853,7 @@ public function relation($relationName)
         return $relation;
     }
 
-    public function dbObject($fieldName)
+    public function dbObject(string $fieldName): ?DBField
     {
         return singleton($this->dataClass)->dbObject($fieldName);
     }
diff --git a/src/ORM/DataObject.php b/src/ORM/DataObject.php
index 2b6bed1dae7..91325064565 100644
--- a/src/ORM/DataObject.php
+++ b/src/ORM/DataObject.php
@@ -104,9 +104,6 @@
  * }
  * </code>
  *
- * If any public method on this class is prefixed with an underscore,
- * the results are cached in memory through {@link cachedCall()}.
- *
  * @property int $ID ID of the DataObject, 0 if the DataObject doesn't exist in database.
  * @property int $OldID ID of object, if deleted
  * @property string $Title
@@ -3033,7 +3030,7 @@ public function setCastedField($fieldName, $value)
     /**
      * {@inheritdoc}
      */
-    public function castingHelper(string $field, bool $useFallback = true): ?string
+    public function castingHelper(string $field): ?string
     {
         $fieldSpec = static::getSchema()->fieldSpec(static::class, $field);
         if ($fieldSpec) {
@@ -3051,7 +3048,7 @@ public function castingHelper(string $field, bool $useFallback = true): ?string
             }
         }
 
-        return parent::castingHelper($field, $useFallback);
+        return parent::castingHelper($field);
     }
 
     /**
@@ -3234,11 +3231,11 @@ public function debug(): string
      *   - it still returns an object even when the field has no value.
      *   - it only matches fields and not methods
      *   - it matches foreign keys generated by has_one relationships, eg, "ParentID"
+     *   - if the field exists, the return value is ALWAYS a DBField instance
      *
-     * @param string $fieldName Name of the field
-     * @return DBField The field as a DBField object
+     * Returns null if the field doesn't exist
      */
-    public function dbObject($fieldName)
+    public function dbObject(string $fieldName): ?DBField
     {
         // Check for field in DB
         $schema = static::getSchema();
@@ -3306,7 +3303,7 @@ public function relObject($fieldPath)
             } elseif ($component instanceof Relation || $component instanceof DataList) {
                 // $relation could either be a field (aggregate), or another relation
                 $singleton = DataObject::singleton($component->dataClass());
-                $component = $singleton->dbObject($relation) ?: $component->relation($relation);
+                $component = $singleton->dbObject($relation) ?? $component->relation($relation);
             } elseif ($component instanceof DataObject && ($dbObject = $component->dbObject($relation))) {
                 $component = $dbObject;
             } elseif ($component instanceof ModelData && $component->hasField($relation)) {
@@ -4399,7 +4396,7 @@ public function hasValue(string $field, array $arguments = [], bool $cache = tru
         // has_one fields should not use dbObject to check if a value is given
         $hasOne = static::getSchema()->hasOneComponent(static::class, $field);
         if (!$hasOne && ($obj = $this->dbObject($field))) {
-            return $obj->exists();
+            return $obj && $obj->exists();
         } else {
             return parent::hasValue($field, $arguments, $cache);
         }
diff --git a/src/ORM/EagerLoadedList.php b/src/ORM/EagerLoadedList.php
index d65a49d3767..ad53ad42e3c 100644
--- a/src/ORM/EagerLoadedList.php
+++ b/src/ORM/EagerLoadedList.php
@@ -171,7 +171,7 @@ public function dataClass(): string
         return $this->dataClass;
     }
 
-    public function dbObject($fieldName): ?DBField
+    public function dbObject(string $fieldName): ?DBField
     {
         return singleton($this->dataClass)->dbObject($fieldName);
     }
diff --git a/src/ORM/FieldType/DBComposite.php b/src/ORM/FieldType/DBComposite.php
index 7060417eadc..6c9ea2a05d4 100644
--- a/src/ORM/FieldType/DBComposite.php
+++ b/src/ORM/FieldType/DBComposite.php
@@ -73,7 +73,7 @@ public function writeToManipulation(array &$manipulation): void
         foreach ($this->compositeDatabaseFields() as $field => $spec) {
             // Write sub-manipulation
             $fieldObject = $this->dbObject($field);
-            $fieldObject->writeToManipulation($manipulation);
+            $fieldObject?->writeToManipulation($manipulation);
         }
     }
 
@@ -137,7 +137,7 @@ public function exists(): bool
         // By default all fields
         foreach ($this->compositeDatabaseFields() as $field => $spec) {
             $fieldObject = $this->dbObject($field);
-            if (!$fieldObject->exists()) {
+            if (!$fieldObject?->exists()) {
                 return false;
             }
         }
diff --git a/src/ORM/FieldType/DBField.php b/src/ORM/FieldType/DBField.php
index 38efb57583f..8d7254aa3ff 100644
--- a/src/ORM/FieldType/DBField.php
+++ b/src/ORM/FieldType/DBField.php
@@ -520,11 +520,6 @@ public function debug(): string
 DBG;
     }
 
-    public function __toString(): string
-    {
-        return (string)$this->forTemplate();
-    }
-
     public function getArrayValue()
     {
         return $this->arrayValue;
diff --git a/src/ORM/FieldType/DBVarchar.php b/src/ORM/FieldType/DBVarchar.php
index 3081ad34be0..86608a19739 100644
--- a/src/ORM/FieldType/DBVarchar.php
+++ b/src/ORM/FieldType/DBVarchar.php
@@ -47,7 +47,7 @@ public function __construct(?string $name = null, int $size = 255, array $option
      * can be useful if you want to have text fields with a length limit that
      * is dictated by the DB field.
      *
-     * TextField::create('Title')->setMaxLength(singleton('SiteTree')->dbObject('Title')->getSize())
+     * TextField::create('Title')->setMaxLength(singleton('SiteTree')->dbObject('Title')?->getSize())
      *
      * @return int The size of the field
      */
diff --git a/src/ORM/Filters/SearchFilter.php b/src/ORM/Filters/SearchFilter.php
index f622252fbb0..bc70ec5d438 100644
--- a/src/ORM/Filters/SearchFilter.php
+++ b/src/ORM/Filters/SearchFilter.php
@@ -339,7 +339,7 @@ public function getDbFormattedValue()
 
         /** @var DBField $dbField */
         $dbField = singleton($this->model)->dbObject($this->name);
-        $dbField->setValue($this->value);
+        $dbField?->setValue($this->value);
         return $dbField->RAW();
     }
 
diff --git a/src/ORM/Relation.php b/src/ORM/Relation.php
index 62b2b266cb2..93c63e961ff 100644
--- a/src/ORM/Relation.php
+++ b/src/ORM/Relation.php
@@ -45,9 +45,6 @@ public function getIDList();
 
     /**
      * Return the DBField object that represents the given field on the related class.
-     *
-     * @param string $fieldName Name of the field
-     * @return DBField The field as a DBField object
      */
-    public function dbObject($fieldName);
+    public function dbObject(string $fieldName): ?DBField;
 }
diff --git a/src/ORM/UnsavedRelationList.php b/src/ORM/UnsavedRelationList.php
index e01ff241e17..ab2780288bb 100644
--- a/src/ORM/UnsavedRelationList.php
+++ b/src/ORM/UnsavedRelationList.php
@@ -307,11 +307,8 @@ public function relation($relationName)
 
     /**
      * Return the DBField object that represents the given field on the related class.
-     *
-     * @param string $fieldName Name of the field
-     * @return DBField The field as a DBField object
      */
-    public function dbObject($fieldName)
+    public function dbObject(string $fieldName): ?DBField
     {
         return DataObject::singleton($this->dataClass)->dbObject($fieldName);
     }
diff --git a/src/PolyExecution/PolyOutput.php b/src/PolyExecution/PolyOutput.php
index a10d4646e54..35b52af39e1 100644
--- a/src/PolyExecution/PolyOutput.php
+++ b/src/PolyExecution/PolyOutput.php
@@ -226,9 +226,6 @@ private function writeListItemAnsi(iterable $items, ?int $options): void
     {
         $listInfo = $this->listTypeStack[array_key_last($this->listTypeStack)];
         $listType = $listInfo['type'];
-        if ($listType === PolyOutput::LIST_ORDERED) {
-            echo '';
-        }
         if ($options === null) {
             $options = $listInfo['options'];
         }
diff --git a/src/Security/Member.php b/src/Security/Member.php
index cfcee6b786a..328c8ebf0ca 100644
--- a/src/Security/Member.php
+++ b/src/Security/Member.php
@@ -342,7 +342,7 @@ public function isLockedOut()
     {
         /** @var DBDatetime $lockedOutUntilObj */
         $lockedOutUntilObj = $this->dbObject('LockedOutUntil');
-        if ($lockedOutUntilObj->InFuture()) {
+        if ($lockedOutUntilObj?->InFuture()) {
             return true;
         }
 
@@ -369,7 +369,7 @@ public function isLockedOut()
         /** @var DBDatetime $firstFailureDate */
         $firstFailureDate = $attempts->first()->dbObject('Created');
         $maxAgeSeconds = $this->config()->get('lock_out_delay_mins') * 60;
-        $lockedOutUntil = $firstFailureDate->getTimestamp() + $maxAgeSeconds;
+        $lockedOutUntil = $firstFailureDate?->getTimestamp() + $maxAgeSeconds;
         $now = DBDatetime::now()->getTimestamp();
         if ($now < $lockedOutUntil) {
             return true;
@@ -429,7 +429,7 @@ public function saveRequiresPasswordChangeOnNextLogin(?int $dataValue): static
         $currentValue = $this->PasswordExpiry;
         $currentDate = $this->dbObject('PasswordExpiry');
 
-        if ($dataValue && (!$currentValue || $currentDate->inFuture())) {
+        if ($dataValue && (!$currentValue || $currentDate?->inFuture())) {
             // Only alter future expiries - this way an admin could see how long ago a password expired still
             $this->PasswordExpiry = DBDatetime::now()->Rfc2822();
         } elseif (!$dataValue && $this->isPasswordExpired()) {
diff --git a/src/Security/PermissionCheckboxSetField.php b/src/Security/PermissionCheckboxSetField.php
index bad09fa4f3b..08c353e3b04 100644
--- a/src/Security/PermissionCheckboxSetField.php
+++ b/src/Security/PermissionCheckboxSetField.php
@@ -89,7 +89,7 @@ public function getHiddenPermissions()
      * @param array $properties
      * @return string
      */
-    public function Field($properties = [])
+    public function renderField($properties = [])
     {
         $uninheritedCodes = [];
         $inheritedCodes = [];
@@ -117,7 +117,7 @@ public function Field($properties = [])
                 $uninheritedCodes[$permission->Code][] = _t(
                     'SilverStripe\\Security\\PermissionCheckboxSetField.AssignedTo',
                     'assigned to "{title}"',
-                    ['title' => $record->dbObject('Title')->forTemplate()]
+                    ['title' => $record->dbObject('Title')?->forTemplate()]
                 );
             }
 
@@ -135,7 +135,7 @@ public function Field($properties = [])
                                 'SilverStripe\\Security\\PermissionCheckboxSetField.FromRole',
                                 'inherited from role "{title}"',
                                 'A permission inherited from a certain permission role',
-                                ['title' => $role->dbObject('Title')->forTemplate()]
+                                ['title' => $role->dbObject('Title')?->forTemplate()]
                             );
                         }
                     }
@@ -159,8 +159,8 @@ public function Field($properties = [])
                                         'inherited from role "{roletitle}" on group "{grouptitle}"',
                                         'A permission inherited from a role on a certain group',
                                         [
-                                            'roletitle' => $role->dbObject('Title')->forTemplate(),
-                                            'grouptitle' => $parent->dbObject('Title')->forTemplate()
+                                            'roletitle' => $role->dbObject('Title')?->forTemplate(),
+                                            'grouptitle' => $parent->dbObject('Title')?->forTemplate()
                                         ]
                                     );
                                 }
@@ -176,7 +176,7 @@ public function Field($properties = [])
                                     'SilverStripe\\Security\\PermissionCheckboxSetField.FromGroup',
                                     'inherited from group "{title}"',
                                     'A permission inherited from a certain group',
-                                    ['title' => $parent->dbObject('Title')->forTemplate()]
+                                    ['title' => $parent->dbObject('Title')?->forTemplate()]
                                 );
                             }
                         }
diff --git a/src/View/CastingService.php b/src/View/CastingService.php
new file mode 100644
index 00000000000..0d6f7510b7e
--- /dev/null
+++ b/src/View/CastingService.php
@@ -0,0 +1,100 @@
+<?php
+
+namespace SilverStripe\View;
+
+use LogicException;
+use SilverStripe\Core\ClassInfo;
+use SilverStripe\Core\Injector\Injectable;
+use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Model\ArrayData;
+use SilverStripe\Model\List\ArrayList;
+use SilverStripe\Model\ModelData;
+use SilverStripe\ORM\FieldType\DBBoolean;
+use SilverStripe\ORM\FieldType\DBFloat;
+use SilverStripe\ORM\FieldType\DBInt;
+use SilverStripe\ORM\FieldType\DBText;
+
+class CastingService
+{
+    use Injectable;
+
+    /**
+     * Cast a value to the relevant object (usually a DBField instance) for use in the view layer.
+     *
+     * @param null|array|ModelData $source Where the data originates from. This is used both to check for casting helpers
+     * and to help set the value in cast DBField instances.
+     * @param bool $strict If true, an object will be returned even if $data is null.
+     */
+    public function cast(mixed $data, null|array|ModelData $source = null, string $fieldName = '', bool $strict = false): ?object
+    {
+        // null is null - we shouldn't cast it to an object, because that makes it harder
+        // for downstream checks to know there's "no value".
+        if (!$strict && $data === null) {
+            return null;
+        }
+
+        // Assume anything that's an object is intentionally using whatever class it's using
+        // and don't cast it.
+        if (is_object($data)) {
+            return $data;
+        }
+
+        $service = null;
+        if ($source instanceof ModelData) {
+            $service = $source->castingHelper($fieldName);
+        }
+
+        // Cast to object if there's an explicit casting for this field
+        // Explicit casts take precedence over array casting
+        if ($service) {
+            $castObject = Injector::inst()->create($service, $fieldName);
+            if (!ClassInfo::hasMethod($castObject, 'setValue')) {
+                throw new LogicException('Explicit casting service must have a setValue method.');
+            }
+            $castObject->setValue($data, $source);
+            return $castObject;
+        }
+
+        // Wrap arrays in ModelData so templates can handle them
+        if (is_array($data)) {
+            return array_is_list($data) ? ArrayList::create($data) : ArrayData::create($data);
+        }
+
+        // Fall back to default casting
+        $service = $this->defaultService($data, $source, $fieldName);
+        $castObject = Injector::inst()->create($service, $fieldName);
+        if (!ClassInfo::hasMethod($castObject, 'setValue')) {
+            throw new LogicException('Default service must have a setValue method.');
+        }
+        $castObject->setValue($data, $source);
+        return $castObject;
+    }
+
+    /**
+     * Get the default service to use if no explicit service is declared for this field on the source model.
+     */
+    private function defaultService(mixed $data, mixed $source = null, string $fieldName = ''): ?string
+    {
+        $default = null;
+        if ($source instanceof ModelData) {
+            $default = $source::config()->get('default_cast');
+            if ($default === null) {
+                $failover = $source->getFailover();
+                if ($failover) {
+                    $default = $this->defaultService($data, $failover, $fieldName);
+                }
+            }
+        }
+        if ($default !== null) {
+            return $default;
+        }
+
+        return match (gettype($data)) {
+            'boolean' => DBBoolean::class,
+            'string' => DBText::class,
+            'double' => DBFloat::class,
+            'integer' => DBInt::class,
+            default => DBText::class,
+        };
+    }
+}
diff --git a/src/View/SSTemplateParser.peg b/src/View/SSTemplateParser.peg
index b893ef4ae5e..cc5c28d2e72 100644
--- a/src/View/SSTemplateParser.peg
+++ b/src/View/SSTemplateParser.peg
@@ -247,7 +247,7 @@ class SSTemplateParser extends Parser implements TemplateParser
         }
 
         $res['php'] .= ($sub['ArgumentMode'] == 'default') ? $sub['string_php'] :
-            str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '');
+            str_replace('$$FINAL', 'getValueAsArgument', $sub['php'] ?? '');
     }
 
     /*!*
@@ -274,8 +274,8 @@ class SSTemplateParser extends Parser implements TemplateParser
     }
 
     /**
-     * The basic generated PHP of LookupStep and LastLookupStep is the same, except that LookupStep calls 'obj' to
-     * get the next ModelData in the sequence, and LastLookupStep calls different methods (XML_val, hasValue, obj)
+     * The basic generated PHP of LookupStep and LastLookupStep is the same, except that LookupStep calls 'scopeToIntermediateValue' to
+     * get the next ModelData in the sequence, and LastLookupStep calls different methods (getOutputValue, hasValue, scopeToIntermediateValue)
      * depending on the context the lookup is used in.
      */
     function Lookup_AddLookupStep(&$res, $sub, $method)
@@ -286,15 +286,17 @@ class SSTemplateParser extends Parser implements TemplateParser
 
         if (isset($sub['Call']['CallArguments']) && isset($sub['Call']['CallArguments']['php'])) {
             $arguments = $sub['Call']['CallArguments']['php'];
-            $res['php'] .= "->$method('$property', [$arguments], true)";
+            $type = ViewLayerData::TYPE_METHOD;
+            $res['php'] .= "->$method('$property', [$arguments], '$type')";
         } else {
-            $res['php'] .= "->$method('$property', [], true)";
+            $type = ViewLayerData::TYPE_PROPERTY;
+            $res['php'] .= "->$method('$property', [], '$type')";
         }
     }
 
     function Lookup_LookupStep(&$res, $sub)
     {
-        $this->Lookup_AddLookupStep($res, $sub, 'obj');
+        $this->Lookup_AddLookupStep($res, $sub, 'scopeToIntermediateValue');
     }
 
     function Lookup_LastLookupStep(&$res, $sub)
@@ -357,7 +359,7 @@ class SSTemplateParser extends Parser implements TemplateParser
 
     function InjectionVariables_Argument(&$res, $sub)
     {
-        $res['php'] .= str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '') . ',';
+        $res['php'] .= str_replace('$$FINAL', 'getOutputValue', $sub['php'] ?? '') . ',';
     }
 
     function InjectionVariables__finalise(&$res)
@@ -392,7 +394,7 @@ class SSTemplateParser extends Parser implements TemplateParser
     */
     function Injection_STR(&$res, $sub)
     {
-        $res['php'] = '$val .= '. str_replace('$$FINAL', 'XML_val', $sub['Lookup']['php'] ?? '') . ';';
+        $res['php'] = '$val .= '. str_replace('$$FINAL', 'getOutputValue', $sub['Lookup']['php'] ?? '') . ';';
     }
 
     /*!*
@@ -535,10 +537,10 @@ class SSTemplateParser extends Parser implements TemplateParser
             if (!empty($res['php'])) {
                 $res['php'] .= $sub['string_php'];
             } else {
-                $res['php'] = str_replace('$$FINAL', 'XML_val', $sub['lookup_php'] ?? '');
+                $res['php'] = str_replace('$$FINAL', 'getOutputValue', $sub['lookup_php'] ?? '');
             }
         } else {
-            $res['php'] .= str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '');
+            $res['php'] .= str_replace('$$FINAL', 'getOutputValue', $sub['php'] ?? '');
         }
     }
 
@@ -567,7 +569,7 @@ class SSTemplateParser extends Parser implements TemplateParser
         } else {
             $php = ($sub['ArgumentMode'] == 'default' ? $sub['lookup_php'] : $sub['php']);
             // TODO: kinda hacky - maybe we need a way to pass state down the parse chain so
-            // Lookup_LastLookupStep and Argument_BareWord can produce hasValue instead of XML_val
+            // Lookup_LastLookupStep and Argument_BareWord can produce hasValue instead of getOutputValue
             $res['php'] .= str_replace('$$FINAL', 'hasValue', $php ?? '');
         }
     }
@@ -697,7 +699,7 @@ class SSTemplateParser extends Parser implements TemplateParser
             $res['php'] = '';
         }
 
-        $res['php'] .= str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '');
+        $res['php'] .= str_replace('$$FINAL', 'getOutputValue', $sub['php'] ?? '');
     }
 
     /*!*
@@ -827,7 +829,7 @@ class SSTemplateParser extends Parser implements TemplateParser
     {
         $entity = $sub['String']['text'];
         if (strpos($entity ?? '', '.') === false) {
-            $res['php'] .= "\$scope->XML_val('I18NNamespace').'.$entity'";
+            $res['php'] .= "\$scope->getOutputValue('I18NNamespace').'.$entity'";
         } else {
             $res['php'] .= "'$entity'";
         }
@@ -915,7 +917,7 @@ class SSTemplateParser extends Parser implements TemplateParser
                 break;
 
             default:
-                $res['php'] .= str_replace('$$FINAL', 'obj', $sub['php'] ?? '') . '->self()';
+                $res['php'] .= str_replace('$$FINAL', 'scopeToIntermediateValue', $sub['php'] ?? '') . '->self()';
                 break;
         }
     }
@@ -948,7 +950,7 @@ class SSTemplateParser extends Parser implements TemplateParser
         $arguments = $res['arguments'];
 
         // Note: 'type' here is important to disable subTemplates in SSViewer::getSubtemplateFor()
-        $res['php'] = '$val .= \\SilverStripe\\View\\SSViewer::execute_template([["type" => "Includes", '.$template.'], '.$template.'], $scope->getItem(), [' .
+        $res['php'] = '$val .= \\SilverStripe\\View\\SSViewer::execute_template([["type" => "Includes", '.$template.'], '.$template.'], $scope->getCurrentItem(), [' .
             implode(',', $arguments)."], \$scope, true);\n";
 
         if ($this->includeDebuggingComments) { // Add include filename comments on dev sites
@@ -1037,7 +1039,8 @@ class SSTemplateParser extends Parser implements TemplateParser
 
         //loop without arguments loops on the current scope
         if ($res['ArgumentCount'] == 0) {
-            $on = '$scope->locally()->obj(\'Me\', [], true)';
+            $type = ViewLayerData::TYPE_METHOD;
+            $on = "\$scope->locally()->scopeToIntermediateValue('Me', [], '$type')"; // @TODO use self instead or move $Me to scope explicitly
         } else {    //loop in the normal way
             $arg = $res['Arguments'][0];
             if ($arg['ArgumentMode'] == 'string') {
@@ -1045,13 +1048,13 @@ class SSTemplateParser extends Parser implements TemplateParser
             }
             $on = str_replace(
                 '$$FINAL',
-                'obj',
+                'scopeToIntermediateValue',
                 ($arg['ArgumentMode'] == 'default') ? $arg['lookup_php'] : $arg['php']
             );
         }
 
         return
-            $on . '; $scope->pushScope(); while (($key = $scope->next()) !== false) {' . PHP_EOL .
+            $on . '; $scope->pushScope(); while ($scope->next() !== false) {' . PHP_EOL .
                 $res['Template']['php'] . PHP_EOL .
             '}; $scope->popScope(); ';
     }
@@ -1071,7 +1074,7 @@ class SSTemplateParser extends Parser implements TemplateParser
             throw new SSTemplateParseException('Control block cant take string as argument.', $this);
         }
 
-        $on = str_replace('$$FINAL', 'obj', ($arg['ArgumentMode'] == 'default') ? $arg['lookup_php'] : $arg['php']);
+        $on = str_replace('$$FINAL', 'scopeToIntermediateValue', ($arg['ArgumentMode'] == 'default') ? $arg['lookup_php'] : $arg['php']);
         return
             $on . '; $scope->pushScope();' . PHP_EOL .
                 $res['Template']['php'] . PHP_EOL .
@@ -1118,6 +1121,7 @@ class SSTemplateParser extends Parser implements TemplateParser
 
     /**
      * This is an open block handler, for the <% debug %> utility tag
+     * @TODO find out if this even works in CMS 5, and if so make sure it keeps working
      */
     function OpenBlock_Handle_Debug(&$res)
     {
diff --git a/src/View/SSTemplateParser.php b/src/View/SSTemplateParser.php
index 4e48424898a..7731704e95e 100644
--- a/src/View/SSTemplateParser.php
+++ b/src/View/SSTemplateParser.php
@@ -572,7 +572,7 @@ function CallArguments_Argument(&$res, $sub)
         }
 
         $res['php'] .= ($sub['ArgumentMode'] == 'default') ? $sub['string_php'] :
-            str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '');
+            str_replace('$$FINAL', 'getValueAsArgument', $sub['php'] ?? '');
     }
 
     /* Call: Method:Word ( "(" < :CallArguments? > ")" )? */
@@ -765,8 +765,8 @@ function Lookup__construct(&$res)
     }
 
     /**
-     * The basic generated PHP of LookupStep and LastLookupStep is the same, except that LookupStep calls 'obj' to
-     * get the next ModelData in the sequence, and LastLookupStep calls different methods (XML_val, hasValue, obj)
+     * The basic generated PHP of LookupStep and LastLookupStep is the same, except that LookupStep calls 'scopeToIntermediateValue' to
+     * get the next ModelData in the sequence, and LastLookupStep calls different methods (getOutputValue, hasValue, scopeToIntermediateValue)
      * depending on the context the lookup is used in.
      */
     function Lookup_AddLookupStep(&$res, $sub, $method)
@@ -777,15 +777,17 @@ function Lookup_AddLookupStep(&$res, $sub, $method)
 
         if (isset($sub['Call']['CallArguments']) && isset($sub['Call']['CallArguments']['php'])) {
             $arguments = $sub['Call']['CallArguments']['php'];
-            $res['php'] .= "->$method('$property', [$arguments], true)";
+            $type = ViewLayerData::TYPE_METHOD;
+            $res['php'] .= "->$method('$property', [$arguments], '$type')";
         } else {
-            $res['php'] .= "->$method('$property', [], true)";
+            $type = ViewLayerData::TYPE_PROPERTY;
+            $res['php'] .= "->$method('$property', [], '$type')";
         }
     }
 
     function Lookup_LookupStep(&$res, $sub)
     {
-        $this->Lookup_AddLookupStep($res, $sub, 'obj');
+        $this->Lookup_AddLookupStep($res, $sub, 'scopeToIntermediateValue');
     }
 
     function Lookup_LastLookupStep(&$res, $sub)
@@ -1009,7 +1011,7 @@ function InjectionVariables_InjectionName(&$res, $sub)
 
     function InjectionVariables_Argument(&$res, $sub)
     {
-        $res['php'] .= str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '') . ',';
+        $res['php'] .= str_replace('$$FINAL', 'getOutputValue', $sub['php'] ?? '') . ',';
     }
 
     function InjectionVariables__finalise(&$res)
@@ -1158,7 +1160,7 @@ function match_Injection ($stack = array()) {
 
     function Injection_STR(&$res, $sub)
     {
-        $res['php'] = '$val .= '. str_replace('$$FINAL', 'XML_val', $sub['Lookup']['php'] ?? '') . ';';
+        $res['php'] = '$val .= '. str_replace('$$FINAL', 'getOutputValue', $sub['Lookup']['php'] ?? '') . ';';
     }
 
     /* DollarMarkedLookup: SimpleInjection */
@@ -1187,7 +1189,7 @@ function match_QuotedString ($stack = array()) {
     	$matchrule = "QuotedString"; $result = $this->construct($matchrule, $matchrule, null);
     	$_154 = NULL;
     	do {
-    		$stack[] = $result; $result = $this->construct( $matchrule, "q" );
+    		$stack[] = $result; $result = $this->construct( $matchrule, "q" ); 
     		if (( $subres = $this->rx( '/[\'"]/' ) ) !== FALSE) {
     			$result["text"] .= $subres;
     			$subres = $result; $result = array_pop($stack);
@@ -1197,7 +1199,7 @@ function match_QuotedString ($stack = array()) {
     			$result = array_pop($stack);
     			$_154 = FALSE; break;
     		}
-    		$stack[] = $result; $result = $this->construct( $matchrule, "String" );
+    		$stack[] = $result; $result = $this->construct( $matchrule, "String" ); 
     		if (( $subres = $this->rx( '/ (\\\\\\\\ | \\\\. | [^'.$this->expression($result, $stack, 'q').'\\\\])* /' ) ) !== FALSE) {
     			$result["text"] .= $subres;
     			$subres = $result; $result = array_pop($stack);
@@ -1818,10 +1820,10 @@ function Comparison_Argument(&$res, $sub)
             if (!empty($res['php'])) {
                 $res['php'] .= $sub['string_php'];
             } else {
-                $res['php'] = str_replace('$$FINAL', 'XML_val', $sub['lookup_php'] ?? '');
+                $res['php'] = str_replace('$$FINAL', 'getOutputValue', $sub['lookup_php'] ?? '');
             }
         } else {
-            $res['php'] .= str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '');
+            $res['php'] .= str_replace('$$FINAL', 'getOutputValue', $sub['php'] ?? '');
         }
     }
 
@@ -1840,7 +1842,7 @@ function match_PresenceCheck ($stack = array()) {
     		$pos_255 = $this->pos;
     		$_254 = NULL;
     		do {
-    			$stack[] = $result; $result = $this->construct( $matchrule, "Not" );
+    			$stack[] = $result; $result = $this->construct( $matchrule, "Not" ); 
     			if (( $subres = $this->literal( 'not' ) ) !== FALSE) {
     				$result["text"] .= $subres;
     				$subres = $result; $result = array_pop($stack);
@@ -1887,7 +1889,7 @@ function PresenceCheck_Argument(&$res, $sub)
         } else {
             $php = ($sub['ArgumentMode'] == 'default' ? $sub['lookup_php'] : $sub['php']);
             // TODO: kinda hacky - maybe we need a way to pass state down the parse chain so
-            // Lookup_LastLookupStep and Argument_BareWord can produce hasValue instead of XML_val
+            // Lookup_LastLookupStep and Argument_BareWord can produce hasValue instead of getOutputValue
             $res['php'] .= str_replace('$$FINAL', 'hasValue', $php ?? '');
         }
     }
@@ -2235,7 +2237,7 @@ function match_Require ($stack = array()) {
     		else { $_330 = FALSE; break; }
     		if (( $subres = $this->whitespace(  ) ) !== FALSE) { $result["text"] .= $subres; }
     		else { $_330 = FALSE; break; }
-    		$stack[] = $result; $result = $this->construct( $matchrule, "Call" );
+    		$stack[] = $result; $result = $this->construct( $matchrule, "Call" ); 
     		$_326 = NULL;
     		do {
     			$matcher = 'match_'.'Word'; $key = $matcher; $pos = $this->pos;
@@ -2470,7 +2472,7 @@ function CacheBlockArguments_CacheBlockArgument(&$res, $sub)
             $res['php'] = '';
         }
 
-        $res['php'] .= str_replace('$$FINAL', 'XML_val', $sub['php'] ?? '');
+        $res['php'] .= str_replace('$$FINAL', 'getOutputValue', $sub['php'] ?? '');
     }
 
     /* CacheBlockTemplate: (Comment | Translate | If | Require |    OldI18NTag | Include | ClosedBlock |
@@ -2740,7 +2742,7 @@ function match_UncachedBlock ($stack = array()) {
     		$_423 = NULL;
     		do {
     			if (( $subres = $this->whitespace(  ) ) !== FALSE) { $result["text"] .= $subres; }
-    			$stack[] = $result; $result = $this->construct( $matchrule, "Conditional" );
+    			$stack[] = $result; $result = $this->construct( $matchrule, "Conditional" ); 
     			$_419 = NULL;
     			do {
     				$_417 = NULL;
@@ -3166,7 +3168,7 @@ function match_CacheBlock ($stack = array()) {
     		if (( $subres = $this->literal( '<%' ) ) !== FALSE) { $result["text"] .= $subres; }
     		else { $_555 = FALSE; break; }
     		if (( $subres = $this->whitespace(  ) ) !== FALSE) { $result["text"] .= $subres; }
-    		$stack[] = $result; $result = $this->construct( $matchrule, "CacheTag" );
+    		$stack[] = $result; $result = $this->construct( $matchrule, "CacheTag" ); 
     		$_508 = NULL;
     		do {
     			$_506 = NULL;
@@ -3225,7 +3227,7 @@ function match_CacheBlock ($stack = array()) {
     		$_524 = NULL;
     		do {
     			if (( $subres = $this->whitespace(  ) ) !== FALSE) { $result["text"] .= $subres; }
-    			$stack[] = $result; $result = $this->construct( $matchrule, "Conditional" );
+    			$stack[] = $result; $result = $this->construct( $matchrule, "Conditional" ); 
     			$_520 = NULL;
     			do {
     				$_518 = NULL;
@@ -3587,7 +3589,7 @@ function OldTPart_QuotedString(&$res, $sub)
     {
         $entity = $sub['String']['text'];
         if (strpos($entity ?? '', '.') === false) {
-            $res['php'] .= "\$scope->XML_val('I18NNamespace').'.$entity'";
+            $res['php'] .= "\$scope->getOutputValue('I18NNamespace').'.$entity'";
         } else {
             $res['php'] .= "'$entity'";
         }
@@ -3792,7 +3794,7 @@ function NamedArgument_Value(&$res, $sub)
                 break;
 
             default:
-                $res['php'] .= str_replace('$$FINAL', 'obj', $sub['php'] ?? '') . '->self()';
+                $res['php'] .= str_replace('$$FINAL', 'scopeToIntermediateValue', $sub['php'] ?? '') . '->self()';
                 break;
         }
     }
@@ -3897,7 +3899,7 @@ function Include__finalise(&$res)
         $arguments = $res['arguments'];
 
         // Note: 'type' here is important to disable subTemplates in SSViewer::getSubtemplateFor()
-        $res['php'] = '$val .= \\SilverStripe\\View\\SSViewer::execute_template([["type" => "Includes", '.$template.'], '.$template.'], $scope->getItem(), [' .
+        $res['php'] = '$val .= \\SilverStripe\\View\\SSViewer::execute_template([["type" => "Includes", '.$template.'], '.$template.'], $scope->getCurrentItem(), [' .
             implode(',', $arguments)."], \$scope, true);\n";
 
         if ($this->includeDebuggingComments) { // Add include filename comments on dev sites
@@ -4165,7 +4167,7 @@ function match_ClosedBlock ($stack = array()) {
     			unset( $pos_685 );
     		}
     		if (( $subres = $this->whitespace(  ) ) !== FALSE) { $result["text"] .= $subres; }
-    		$stack[] = $result; $result = $this->construct( $matchrule, "Zap" );
+    		$stack[] = $result; $result = $this->construct( $matchrule, "Zap" ); 
     		if (( $subres = $this->literal( '%>' ) ) !== FALSE) {
     			$result["text"] .= $subres;
     			$subres = $result; $result = array_pop($stack);
@@ -4265,7 +4267,8 @@ function ClosedBlock_Handle_Loop(&$res)
 
         //loop without arguments loops on the current scope
         if ($res['ArgumentCount'] == 0) {
-            $on = '$scope->locally()->obj(\'Me\', [], true)';
+            $type = ViewLayerData::TYPE_METHOD;
+            $on = "\$scope->locally()->scopeToIntermediateValue('Me', [], '$type')"; // @TODO use self instead or move $Me to scope explicitly
         } else {    //loop in the normal way
             $arg = $res['Arguments'][0];
             if ($arg['ArgumentMode'] == 'string') {
@@ -4273,13 +4276,13 @@ function ClosedBlock_Handle_Loop(&$res)
             }
             $on = str_replace(
                 '$$FINAL',
-                'obj',
+                'scopeToIntermediateValue',
                 ($arg['ArgumentMode'] == 'default') ? $arg['lookup_php'] : $arg['php']
             );
         }
 
         return
-            $on . '; $scope->pushScope(); while (($key = $scope->next()) !== false) {' . PHP_EOL .
+            $on . '; $scope->pushScope(); while ($scope->next() !== false) {' . PHP_EOL .
                 $res['Template']['php'] . PHP_EOL .
             '}; $scope->popScope(); ';
     }
@@ -4299,7 +4302,7 @@ function ClosedBlock_Handle_With(&$res)
             throw new SSTemplateParseException('Control block cant take string as argument.', $this);
         }
 
-        $on = str_replace('$$FINAL', 'obj', ($arg['ArgumentMode'] == 'default') ? $arg['lookup_php'] : $arg['php']);
+        $on = str_replace('$$FINAL', 'scopeToIntermediateValue', ($arg['ArgumentMode'] == 'default') ? $arg['lookup_php'] : $arg['php']);
         return
             $on . '; $scope->pushScope();' . PHP_EOL .
                 $res['Template']['php'] . PHP_EOL .
@@ -4403,6 +4406,7 @@ function OpenBlock__finalise(&$res)
 
     /**
      * This is an open block handler, for the <% debug %> utility tag
+     * @TODO find out if this even works in CMS 5, and if so make sure it keeps working
      */
     function OpenBlock_Handle_Debug(&$res)
     {
@@ -4575,7 +4579,7 @@ function match_MalformedCloseTag ($stack = array()) {
     		if (( $subres = $this->literal( '<%' ) ) !== FALSE) { $result["text"] .= $subres; }
     		else { $_743 = FALSE; break; }
     		if (( $subres = $this->whitespace(  ) ) !== FALSE) { $result["text"] .= $subres; }
-    		$stack[] = $result; $result = $this->construct( $matchrule, "Tag" );
+    		$stack[] = $result; $result = $this->construct( $matchrule, "Tag" ); 
     		$_737 = NULL;
     		do {
     			if (( $subres = $this->literal( 'end_' ) ) !== FALSE) { $result["text"] .= $subres; }
diff --git a/src/View/SSViewer.php b/src/View/SSViewer.php
index 63f0edc344c..987ad5c4399 100644
--- a/src/View/SSViewer.php
+++ b/src/View/SSViewer.php
@@ -15,6 +15,7 @@
 use SilverStripe\ORM\FieldType\DBHTMLText;
 use SilverStripe\Security\Permission;
 use InvalidArgumentException;
+use RuntimeException;
 use SilverStripe\Model\ModelData;
 
 /**
@@ -550,10 +551,10 @@ public function includeRequirements($incl = true)
      * Effectively this is the common code that both SSViewer#process and SSViewer_FromString#process call
      *
      * @param string $cacheFile The path to the file that contains the template compiled to PHP
-     * @param ModelData $item The item to use as the root scope for the template
+     * @param ViewLayerData $item The item to use as the root scope for the template
      * @param array $overlay Any variables to layer on top of the scope
      * @param array $underlay Any variables to layer underneath the scope
-     * @param ModelData $inheritedScope The current scope of a parent template including a sub-template
+     * @param SSViewer_Scope $inheritedScope The current scope of a parent template including a sub-template
      * @return string The result of executing the template
      */
     protected function includeGeneratedTemplate($cacheFile, $item, $overlay, $underlay, $inheritedScope = null)
@@ -569,7 +570,7 @@ protected function includeGeneratedTemplate($cacheFile, $item, $overlay, $underl
         }
 
         $cache = $this->getPartialCacheStore();
-        $scope = new SSViewer_DataPresenter($item, $overlay, $underlay, $inheritedScope);
+        $scope = new SSViewer_Scope($item, $overlay, $underlay, $inheritedScope);
         $val = '';
 
         // Placeholder for values exposed to $cacheFile
@@ -597,6 +598,7 @@ protected function includeGeneratedTemplate($cacheFile, $item, $overlay, $underl
      */
     public function process($item, $arguments = null, $inheritedScope = null)
     {
+        $item = ViewLayerData::create($item);
         // Set hashlinks and temporarily modify global state
         $rewrite = $this->getRewriteHashLinks();
         $origRewriteDefault = static::getRewriteHashLinksDefault();
@@ -606,6 +608,10 @@ public function process($item, $arguments = null, $inheritedScope = null)
 
         $template = $this->chosen;
 
+        if (!$template) {
+            throw new RuntimeException('No template to render');
+        }
+
         $cacheFile = TEMP_PATH . DIRECTORY_SEPARATOR . '.cache'
             . str_replace(['\\','/',':'], '.', Director::makeRelative(realpath($template ?? '')) ?? '');
         $lastEdited = filemtime($template ?? '');
diff --git a/src/View/SSViewer_DataPresenter.php b/src/View/SSViewer_DataPresenter.php
deleted file mode 100644
index 0729584a22e..00000000000
--- a/src/View/SSViewer_DataPresenter.php
+++ /dev/null
@@ -1,449 +0,0 @@
-<?php
-
-namespace SilverStripe\View;
-
-use InvalidArgumentException;
-use SilverStripe\Core\ClassInfo;
-use SilverStripe\Model\ModelData;
-use SilverStripe\Model\List\ArrayList;
-use SilverStripe\ORM\FieldType\DBField;
-
-/**
- * This extends SSViewer_Scope to mix in data on top of what the item provides. This can be "global"
- * data that is scope-independant (like BaseURL), or type-specific data that is layered on top cross-cut like
- * (like $FirstLast etc).
- *
- * It's separate from SSViewer_Scope to keep that fairly complex code as clean as possible.
- */
-class SSViewer_DataPresenter extends SSViewer_Scope
-{
-    /**
-     * List of global property providers
-     *
-     * @internal
-     * @var TemplateGlobalProvider[]|null
-     */
-    private static $globalProperties = null;
-
-    /**
-     * List of global iterator providers
-     *
-     * @internal
-     * @var TemplateIteratorProvider[]|null
-     */
-    private static $iteratorProperties = null;
-
-    /**
-     * Overlay variables. Take precedence over anything from the current scope
-     *
-     * @var array|null
-     */
-    protected $overlay;
-
-    /**
-     * Flag for whether overlay should be preserved when pushing a new scope
-     *
-     * @see SSViewer_DataPresenter::pushScope()
-     * @var bool
-     */
-    protected $preserveOverlay = false;
-
-    /**
-     * Underlay variables. Concede precedence to overlay variables or anything from the current scope
-     *
-     * @var array
-     */
-    protected $underlay;
-
-    /**
-     * @var object $item
-     * @var array $overlay
-     * @var array $underlay
-     * @var SSViewer_Scope $inheritedScope
-     */
-    public function __construct(
-        $item,
-        array $overlay = null,
-        array $underlay = null,
-        SSViewer_Scope $inheritedScope = null
-    ) {
-        parent::__construct($item, $inheritedScope);
-
-        $this->overlay = $overlay ?: [];
-        $this->underlay = $underlay ?: [];
-
-        $this->cacheGlobalProperties();
-        $this->cacheIteratorProperties();
-    }
-
-    /**
-     * Build cache of global properties
-     */
-    protected function cacheGlobalProperties()
-    {
-        if (SSViewer_DataPresenter::$globalProperties !== null) {
-            return;
-        }
-
-        SSViewer_DataPresenter::$globalProperties = $this->getPropertiesFromProvider(
-            TemplateGlobalProvider::class,
-            'get_template_global_variables'
-        );
-    }
-
-    /**
-     * Build cache of global iterator properties
-     */
-    protected function cacheIteratorProperties()
-    {
-        if (SSViewer_DataPresenter::$iteratorProperties !== null) {
-            return;
-        }
-
-        SSViewer_DataPresenter::$iteratorProperties = $this->getPropertiesFromProvider(
-            TemplateIteratorProvider::class,
-            'get_template_iterator_variables',
-            true // Call non-statically
-        );
-    }
-
-    /**
-     * @var string $interfaceToQuery
-     * @var string $variableMethod
-     * @var boolean $createObject
-     * @return array
-     */
-    protected function getPropertiesFromProvider($interfaceToQuery, $variableMethod, $createObject = false)
-    {
-        $methods = [];
-
-        $implementors = ClassInfo::implementorsOf($interfaceToQuery);
-        if ($implementors) {
-            foreach ($implementors as $implementor) {
-                // Create a new instance of the object for method calls
-                if ($createObject) {
-                    $implementor = new $implementor();
-                    $exposedVariables = $implementor->$variableMethod();
-                } else {
-                    $exposedVariables = $implementor::$variableMethod();
-                }
-
-                foreach ($exposedVariables as $varName => $details) {
-                    if (!is_array($details)) {
-                        $details = [
-                            'method' => $details,
-                            'casting' => ModelData::config()->uninherited('default_cast')
-                        ];
-                    }
-
-                    // If just a value (and not a key => value pair), use method name for both key and value
-                    if (is_numeric($varName)) {
-                        $varName = $details['method'];
-                    }
-
-                    // Add in a reference to the implementing class (might be a string class name or an instance)
-                    $details['implementor'] = $implementor;
-
-                    // And a callable array
-                    if (isset($details['method'])) {
-                        $details['callable'] = [$implementor, $details['method']];
-                    }
-
-                    // Save with both uppercase & lowercase first letter, so either works
-                    $lcFirst = strtolower($varName[0] ?? '') . substr($varName ?? '', 1);
-                    $result[$lcFirst] = $details;
-                    $result[ucfirst($varName)] = $details;
-                }
-            }
-        }
-
-        return $result;
-    }
-
-    /**
-     * Look up injected value - it may be part of an "overlay" (arguments passed to <% include %>),
-     * set on the current item, part of an "underlay" ($Layout or $Content), or an iterator/global property
-     *
-     * @param string $property Name of property
-     * @param array $params
-     * @param bool $cast If true, an object is always returned even if not an object.
-     * @return array|null
-     */
-    public function getInjectedValue($property, array $params, $cast = true)
-    {
-        // Get source for this value
-        $result = $this->getValueSource($property);
-        if (!array_key_exists('source', $result)) {
-            return null;
-        }
-
-        // Look up the value - either from a callable, or from a directly provided value
-        $source = $result['source'];
-        $res = [];
-        if (isset($source['callable'])) {
-            $res['value'] = $source['callable'](...$params);
-        } elseif (array_key_exists('value', $source)) {
-            $res['value'] = $source['value'];
-        } else {
-            throw new InvalidArgumentException(
-                "Injected property $property doesn't have a value or callable value source provided"
-            );
-        }
-
-        // If we want to provide a casted object, look up what type object to use
-        if ($cast) {
-            $res['obj'] = $this->castValue($res['value'], $source);
-        }
-
-        return $res;
-    }
-
-    /**
-     * Store the current overlay (as it doesn't directly apply to the new scope
-     * that's being pushed). We want to store the overlay against the next item
-     * "up" in the stack (hence upIndex), rather than the current item, because
-     * SSViewer_Scope::obj() has already been called and pushed the new item to
-     * the stack by this point
-     *
-     * @return SSViewer_Scope
-     */
-    public function pushScope()
-    {
-        $scope = parent::pushScope();
-        $upIndex = $this->getUpIndex() ?: 0;
-
-        $itemStack = $this->getItemStack();
-        $itemStack[$upIndex][SSViewer_Scope::ITEM_OVERLAY] = $this->overlay;
-        $this->setItemStack($itemStack);
-
-        // Remove the overlay when we're changing to a new scope, as values in
-        // that scope take priority. The exceptions that set this flag are $Up
-        // and $Top as they require that the new scope inherits the overlay
-        if (!$this->preserveOverlay) {
-            $this->overlay = [];
-        }
-
-        return $scope;
-    }
-
-    /**
-     * Now that we're going to jump up an item in the item stack, we need to
-     * restore the overlay that was previously stored against the next item "up"
-     * in the stack from the current one
-     *
-     * @return SSViewer_Scope
-     */
-    public function popScope()
-    {
-        $upIndex = $this->getUpIndex();
-
-        if ($upIndex !== null) {
-            $itemStack = $this->getItemStack();
-            $this->overlay = $itemStack[$upIndex][SSViewer_Scope::ITEM_OVERLAY];
-        }
-
-        return parent::popScope();
-    }
-
-    /**
-     * $Up and $Top need to restore the overlay from the parent and top-level
-     * scope respectively.
-     *
-     * @param string $name
-     * @param array $arguments
-     * @param bool $cache
-     * @param string $cacheName
-     * @return $this
-     */
-    public function obj($name, $arguments = [], $cache = false, $cacheName = null)
-    {
-        $overlayIndex = false;
-
-        switch ($name) {
-            case 'Up':
-                $upIndex = $this->getUpIndex();
-                if ($upIndex === null) {
-                    throw new \LogicException('Up called when we\'re already at the top of the scope');
-                }
-                $overlayIndex = $upIndex; // Parent scope
-                $this->preserveOverlay = true; // Preserve overlay
-                break;
-            case 'Top':
-                $overlayIndex = 0; // Top-level scope
-                $this->preserveOverlay = true; // Preserve overlay
-                break;
-            default:
-                $this->preserveOverlay = false;
-                break;
-        }
-
-        if ($overlayIndex !== false) {
-            $itemStack = $this->getItemStack();
-            if (!$this->overlay && isset($itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY])) {
-                $this->overlay = $itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY];
-            }
-        }
-
-        parent::obj($name, $arguments, $cache, $cacheName);
-        return $this;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getObj($name, $arguments = [], $cache = false, $cacheName = null)
-    {
-        $result = $this->getInjectedValue($name, (array)$arguments);
-        if ($result) {
-            return $result['obj'];
-        }
-        return parent::getObj($name, $arguments, $cache, $cacheName);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function __call($name, $arguments)
-    {
-        // Extract the method name and parameters
-        $property = $arguments[0];  // The name of the public function being called
-
-        // The public function parameters in an array
-        $params = (isset($arguments[1])) ? (array)$arguments[1] : [];
-
-        $val = $this->getInjectedValue($property, $params);
-        if ($val) {
-            $obj = $val['obj'];
-            if ($name === 'hasValue') {
-                $result = ($obj instanceof ModelData) ? $obj->exists() : (bool)$obj;
-            } elseif (is_null($obj) || (is_scalar($obj) && !is_string($obj))) {
-                $result = $obj; // Nulls and non-string scalars don't need casting
-            } else {
-                $result = $obj->forTemplate(); // XML_val
-            }
-
-            $this->resetLocalScope();
-            return $result;
-        }
-
-        return parent::__call($name, $arguments);
-    }
-
-    /**
-     * Evaluate a template override. Returns an array where the presence of
-     * a 'value' key indiciates whether an override was successfully found,
-     * as null is a valid override value
-     *
-     * @param string $property Name of override requested
-     * @param array $overrides List of overrides available
-     * @return array An array with a 'value' key if a value has been found, or empty if not
-     */
-    protected function processTemplateOverride($property, $overrides)
-    {
-        if (!array_key_exists($property, $overrides)) {
-            return [];
-        }
-
-        // Detect override type
-        $override = $overrides[$property];
-
-        // Late-evaluate this value
-        if (!is_string($override) && is_callable($override)) {
-            $override = $override();
-
-            // Late override may yet return null
-            if (!isset($override)) {
-                return [];
-            }
-        }
-
-        return ['value' => $override];
-    }
-
-    /**
-     * Determine source to use for getInjectedValue. Returns an array where the presence of
-     * a 'source' key indiciates whether a value source was successfully found, as a source
-     * may be a null value returned from an override
-     *
-     * @param string $property
-     * @return array An array with a 'source' key if a value source has been found, or empty if not
-     */
-    protected function getValueSource($property)
-    {
-        // Check for a presenter-specific override
-        $result = $this->processTemplateOverride($property, $this->overlay);
-        if (array_key_exists('value', $result)) {
-            return ['source' => $result];
-        }
-
-        // Check if the method to-be-called exists on the target object - if so, don't check any further
-        // injection locations
-        $on = $this->getItem();
-        if (is_object($on) && (isset($on->$property) || method_exists($on, $property ?? ''))) {
-            return [];
-        }
-
-        // Check for a presenter-specific override
-        $result = $this->processTemplateOverride($property, $this->underlay);
-        if (array_key_exists('value', $result)) {
-            return ['source' => $result];
-        }
-
-        // Then for iterator-specific overrides
-        if (array_key_exists($property, SSViewer_DataPresenter::$iteratorProperties)) {
-            $source = SSViewer_DataPresenter::$iteratorProperties[$property];
-            /** @var TemplateIteratorProvider $implementor */
-            $implementor = $source['implementor'];
-            if ($this->itemIterator) {
-                // Set the current iterator position and total (the object instance is the first item in
-                // the callable array)
-                $implementor->iteratorProperties(
-                    $this->itemIterator->key(),
-                    $this->itemIteratorTotal
-                );
-            } else {
-                // If we don't actually have an iterator at the moment, act like a list of length 1
-                $implementor->iteratorProperties(0, 1);
-            }
-
-            return ($source) ? ['source' => $source] : [];
-        }
-
-        // And finally for global overrides
-        if (array_key_exists($property, SSViewer_DataPresenter::$globalProperties)) {
-            return [
-                'source' => SSViewer_DataPresenter::$globalProperties[$property] // get the method call
-            ];
-        }
-
-        // No value
-        return [];
-    }
-
-    /**
-     * Ensure the value is cast safely
-     *
-     * @param mixed $value
-     * @param array $source
-     * @return DBField
-     */
-    protected function castValue($value, $source)
-    {
-        // If the value has already been cast, is null, or is a non-string scalar
-        if (is_object($value) || is_null($value) || (is_scalar($value) && !is_string($value))) {
-            return $value;
-        }
-
-        // Wrap list arrays in ModelData so templates can handle them
-        if (is_array($value) && array_is_list($value)) {
-            return ArrayList::create($value);
-        }
-
-        // Get provided or default cast
-        $casting = empty($source['casting'])
-            ? ModelData::config()->uninherited('default_cast')
-            : $source['casting'];
-
-        return DBField::create_field($casting, $value);
-    }
-}
diff --git a/src/View/SSViewer_FromString.php b/src/View/SSViewer_FromString.php
index c7712a9f2b3..407c6343d94 100644
--- a/src/View/SSViewer_FromString.php
+++ b/src/View/SSViewer_FromString.php
@@ -50,6 +50,7 @@ public function __construct($content, TemplateParser $parser = null)
      */
     public function process($item, $arguments = null, $scope = null)
     {
+        $item = ViewLayerData::create($item);
         $hash = sha1($this->content ?? '');
         $cacheFile = TEMP_PATH . DIRECTORY_SEPARATOR . ".cache.$hash";
 
diff --git a/src/View/SSViewer_Scope.php b/src/View/SSViewer_Scope.php
index 928b7b4a338..74c15f42746 100644
--- a/src/View/SSViewer_Scope.php
+++ b/src/View/SSViewer_Scope.php
@@ -4,12 +4,11 @@
 
 use ArrayIterator;
 use Countable;
+use InvalidArgumentException;
 use Iterator;
-use SilverStripe\Model\List\ArrayList;
-use SilverStripe\ORM\FieldType\DBBoolean;
-use SilverStripe\ORM\FieldType\DBText;
-use SilverStripe\ORM\FieldType\DBFloat;
-use SilverStripe\ORM\FieldType\DBInt;
+use LogicException;
+use SilverStripe\Core\ClassInfo;
+use SilverStripe\Core\Injector\Injector;
 use SilverStripe\ORM\FieldType\DBField;
 
 /**
@@ -18,6 +17,10 @@
  *   - Track Up and Top
  *   - (As a side effect) Inject data that needs to be available globally (used to live in ModelData)
  *
+ * It is also responsible for mixing in data on top of what the item provides. This can be "global"
+ * data that is scope-independant (like BaseURL), or type-specific data that is layered on top cross-cut like
+ * (like $FirstLast etc).
+ *
  * In order to handle up, rather than tracking it using a tree, which would involve constructing new objects
  * for each step, we use indexes into the itemStack (which already has to exist).
  *
@@ -107,37 +110,73 @@ class SSViewer_Scope
      */
     private $localIndex = 0;
 
+    /**
+     * List of global property providers
+     *
+     * @internal
+     * @var TemplateGlobalProvider[]|null
+     */
+    private static $globalProperties = null;
+
+    /**
+     * List of global iterator providers
+     *
+     * @internal
+     * @var TemplateIteratorProvider[]|null
+     */
+    private static $iteratorProperties = null;
+
+    /**
+     * Overlay variables. Take precedence over anything from the current scope
+     *
+     * @var array|null
+     */
+    protected $overlay;
+
+    /**
+     * Flag for whether overlay should be preserved when pushing a new scope
+     *
+     * @see SSViewer_Scope::pushScope()
+     * @var bool
+     */
+    protected $preserveOverlay = false;
+
+    /**
+     * Underlay variables. Concede precedence to overlay variables or anything from the current scope
+     *
+     * @var array
+     */
+    protected $underlay;
+
     /**
      * @var object $item
      * @var SSViewer_Scope $inheritedScope
      */
-    public function __construct($item, SSViewer_Scope $inheritedScope = null)
-    {
+    public function __construct(
+        $item,
+        array $overlay = null,
+        array $underlay = null,
+        SSViewer_Scope $inheritedScope = null
+    ) {
         $this->item = $item;
 
         $this->itemIterator = ($inheritedScope) ? $inheritedScope->itemIterator : null;
         $this->itemIteratorTotal = ($inheritedScope) ? $inheritedScope->itemIteratorTotal : 0;
         $this->itemStack[] = [$this->item, $this->itemIterator, $this->itemIteratorTotal, null, null, 0];
+
+        $this->overlay = $overlay ?: [];
+        $this->underlay = $underlay ?: [];
+
+        $this->cacheGlobalProperties();
+        $this->cacheIteratorProperties();
     }
 
     /**
-     * Returns the current "active" item
-     *
-     * @return object
+     * Returns the current "current" item in scope
      */
-    public function getItem()
+    public function getCurrentItem(): ?ViewLayerData
     {
-        $item = $this->itemIterator ? $this->itemIterator->current() : $this->item;
-        if (is_scalar($item)) {
-            $item = $this->convertScalarToDBField($item);
-        }
-
-        // Wrap list arrays in ModelData so templates can handle them
-        if (is_array($item) && array_is_list($item)) {
-            $item = ArrayList::create($item);
-        }
-
-        return $item;
+        return $this->itemIterator ? $this->itemIterator->current() : $this->item;
     }
 
     /**
@@ -164,56 +203,21 @@ public function locally()
     }
 
     /**
-     * Reset the local scope - restores saved state to the "global" item stack. Typically called after
-     * a lookup chain has been completed
-     */
-    public function resetLocalScope()
-    {
-        // Restore previous un-completed lookup chain if set
-        $previousLocalState = $this->localStack ? array_pop($this->localStack) : null;
-        array_splice($this->itemStack, $this->localIndex + 1, count($this->itemStack ?? []), $previousLocalState);
-
-        list(
-            $this->item,
-            $this->itemIterator,
-            $this->itemIteratorTotal,
-            $this->popIndex,
-            $this->upIndex,
-            $this->currentIndex
-        ) = end($this->itemStack);
-    }
-
-    /**
-     * @param string $name
-     * @param array $arguments
-     * @param bool $cache
-     * @param string $cacheName
-     * @return mixed
+     * Set scope to an intermediate value, which will be used for getting output later on.
      */
-    public function getObj($name, $arguments = [], $cache = false, $cacheName = null)
+    public function scopeToIntermediateValue(string $name, array $arguments, string $type): static
     {
-        $on = $this->getItem();
-        if ($on === null) {
-            return null;
-        }
-        return $on->obj($name, $arguments, $cache, $cacheName);
-    }
+        $overlayIndex = false;
 
-    /**
-     * @param string $name
-     * @param array $arguments
-     * @param bool $cache
-     * @param string $cacheName
-     * @return $this
-     */
-    public function obj($name, $arguments = [], $cache = false, $cacheName = null)
-    {
+        // $Up and $Top need to restore the overlay from the parent and top-level scope respectively.
         switch ($name) {
             case 'Up':
-                if ($this->upIndex === null) {
+                $upIndex = $this->getUpIndex();
+                if ($upIndex === null) {
                     throw new \LogicException('Up called when we\'re already at the top of the scope');
                 }
-
+                $overlayIndex = $upIndex; // Parent scope
+                $this->preserveOverlay = true; // Preserve overlay
                 list(
                     $this->item,
                     $this->itemIterator,
@@ -224,6 +228,8 @@ public function obj($name, $arguments = [], $cache = false, $cacheName = null)
                 ) = $this->itemStack[$this->upIndex];
                 break;
             case 'Top':
+                $overlayIndex = 0; // Top-level scope
+                $this->preserveOverlay = true; // Preserve overlay
                 list(
                     $this->item,
                     $this->itemIterator,
@@ -234,13 +240,21 @@ public function obj($name, $arguments = [], $cache = false, $cacheName = null)
                 ) = $this->itemStack[0];
                 break;
             default:
-                $this->item = $this->getObj($name, $arguments, $cache, $cacheName);
+                $this->preserveOverlay = false;
+                $this->item = $this->getObj($name, $arguments, $type);
                 $this->itemIterator = null;
                 $this->upIndex = $this->currentIndex ? $this->currentIndex : count($this->itemStack) - 1;
                 $this->currentIndex = count($this->itemStack);
                 break;
         }
 
+        if ($overlayIndex !== false) {
+            $itemStack = $this->getItemStack();
+            if (!$this->overlay && isset($itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY])) {
+                $this->overlay = $itemStack[$overlayIndex][SSViewer_Scope::ITEM_OVERLAY];
+            }
+        }
+
         $this->itemStack[] = [
             $this->item,
             $this->itemIterator,
@@ -254,12 +268,11 @@ public function obj($name, $arguments = [], $cache = false, $cacheName = null)
 
     /**
      * Gets the current object and resets the scope.
-     *
-     * @return object
+     * @TODO: Replace with $Me
      */
-    public function self()
+    public function self(): ?ViewLayerData
     {
-        $result = $this->getItem();
+        $result = $this->getCurrentItem();
         $this->resetLocalScope();
 
         return $result;
@@ -268,9 +281,13 @@ public function self()
     /**
      * Jump to the last item in the stack, called when a new item is added before a loop/with
      *
-     * @return SSViewer_Scope
+     * Store the current overlay (as it doesn't directly apply to the new scope
+     * that's being pushed). We want to store the overlay against the next item
+     * "up" in the stack (hence upIndex), rather than the current item, because
+     * SSViewer_Scope::obj() has already been called and pushed the new item to
+     * the stack by this point
      */
-    public function pushScope()
+    public function pushScope(): static
     {
         $newLocalIndex = count($this->itemStack ?? []) - 1;
 
@@ -284,16 +301,38 @@ public function pushScope()
         // once we enter a new global scope, we need to make sure we use a new one
         $this->itemIterator = $this->itemStack[$newLocalIndex][SSViewer_Scope::ITEM_ITERATOR] = null;
 
+        $upIndex = $this->getUpIndex() ?: 0;
+
+        $itemStack = $this->getItemStack();
+        $itemStack[$upIndex][SSViewer_Scope::ITEM_OVERLAY] = $this->overlay;
+        $this->setItemStack($itemStack);
+
+        // Remove the overlay when we're changing to a new scope, as values in
+        // that scope take priority. The exceptions that set this flag are $Up
+        // and $Top as they require that the new scope inherits the overlay
+        if (!$this->preserveOverlay) {
+            $this->overlay = [];
+        }
+
         return $this;
     }
 
     /**
      * Jump back to "previous" item in the stack, called after a loop/with block
      *
-     * @return SSViewer_Scope
+     * Now that we're going to jump up an item in the item stack, we need to
+     * restore the overlay that was previously stored against the next item "up"
+     * in the stack from the current one
      */
-    public function popScope()
+    public function popScope(): static
     {
+        $upIndex = $this->getUpIndex();
+
+        if ($upIndex !== null) {
+            $itemStack = $this->getItemStack();
+            $this->overlay = $itemStack[$upIndex][SSViewer_Scope::ITEM_OVERLAY];
+        }
+
         $this->localIndex = $this->popIndex;
         $this->resetLocalScope();
 
@@ -301,11 +340,10 @@ public function popScope()
     }
 
     /**
-     * Fast-forwards the current iterator to the next item
-     *
-     * @return mixed
+     * Fast-forwards the current iterator to the next item.
+     * @return bool True if there's an item, false if not.
      */
-    public function next()
+    public function next(): bool
     {
         if (!$this->item) {
             return false;
@@ -349,23 +387,143 @@ public function next()
             return false;
         }
 
-        return $this->itemIterator->key();
+        return true;
     }
 
     /**
-     * @param string $name
-     * @param array $arguments
-     * @return mixed
+     * Get the value that will be directly rendered in the template.
      */
-    public function __call($name, $arguments)
+    public function getOutputValue(string $name, array $arguments, string $type): string
     {
-        $on = $this->getItem();
-        $retval = $on ? $on->$name(...$arguments) : null;
+        $retval = $this->getObj($name, $arguments, $type);
+        $this->resetLocalScope();
+        return $retval === null ? '' : $retval->__toString();
+    }
+
+    /**
+     * Get the value to pass as an argument to a method.
+     */
+    public function getValueAsArgument(string $name, array $arguments, string $type): mixed
+    {
+        $retval = null;
+
+        if ($this->hasOverlay($name)) {
+            $retval = $this->getOverlay($name, $arguments, true);
+        } else {
+            $on = $this->getCurrentItem();
+            if ($on && isset($on->$name)) {
+                $retval = $on->getRawDataValue($name, $type, $arguments);
+            }
+
+            if ($retval === null) {
+                $retval = $this->getUnderlay($name, $arguments, true);
+            }
+        }
+
+        // if ($retval instanceof DBField) {
+        //     $retval = $retval->getValue(); // Workaround because we're still calling obj in ViewLayerData
+        // }
+
+        $this->resetLocalScope();
+        return $retval;
+    }
+
+    /**
+     * Check if the current item in scope has a value for the named field.
+     */
+    public function hasValue(string $name, array $arguments): bool
+    {
+        // @TODO: look for ways to remove the need to call hasValue (e.g. using isset($this->getCurrentItem()->$name) and an equivalent for over/underlays)
+        $retval = null;
+        $overlay = $this->getOverlay($name, $arguments);
+        if ($overlay && $overlay->hasDataValue()) {
+            $retval = true;
+        }
+
+        if ($retval === null) {
+            $on = $this->getCurrentItem();
+            if ($on) {
+                $retval = $on->hasDataValue($name, $arguments);
+            }
+        }
+
+        if (!$retval) {
+            $underlay = $this->getUnderlay($name, $arguments);
+            $retval = $underlay && $underlay->hasDataValue();
+        }
 
         $this->resetLocalScope();
         return $retval;
     }
 
+    /**
+     * @var string $interfaceToQuery
+     * @var string $variableMethod
+     * @var boolean $createObject
+     * @return array
+     */
+    protected function getPropertiesFromProvider($interfaceToQuery, $variableMethod, $createObject = false)
+    {
+        $implementors = ClassInfo::implementorsOf($interfaceToQuery);
+        if ($implementors) {
+            foreach ($implementors as $implementor) {
+                // Create a new instance of the object for method calls
+                if ($createObject) {
+                    $implementor = new $implementor();
+                    $exposedVariables = $implementor->$variableMethod();
+                } else {
+                    $exposedVariables = $implementor::$variableMethod();
+                }
+
+                foreach ($exposedVariables as $varName => $details) {
+                    if (!is_array($details)) {
+                        $details = ['method' => $details];
+                    }
+
+                    // If just a value (and not a key => value pair), use method name for both key and value
+                    if (is_numeric($varName)) {
+                        $varName = $details['method'];
+                    }
+
+                    // Add in a reference to the implementing class (might be a string class name or an instance)
+                    $details['implementor'] = $implementor;
+
+                    // And a callable array
+                    if (isset($details['method'])) {
+                        $details['callable'] = [$implementor, $details['method']];
+                    }
+
+                    // Save with both uppercase & lowercase first letter, so either works
+                    $lcFirst = strtolower($varName[0] ?? '') . substr($varName ?? '', 1);
+                    $result[$lcFirst] = $details;
+                    $result[ucfirst($varName)] = $details;
+                }
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Reset the local scope - restores saved state to the "global" item stack. Typically called after
+     * a lookup chain has been completed
+     */
+    protected function resetLocalScope()
+    {
+        // Restore previous un-completed lookup chain if set
+        $previousLocalState = $this->localStack ? array_pop($this->localStack) : null;
+        array_splice($this->itemStack, $this->localIndex + 1, count($this->itemStack ?? []), $previousLocalState);
+
+        list(
+            $this->item,
+            $this->itemIterator,
+            $this->itemIteratorTotal,
+            $this->popIndex,
+            $this->upIndex,
+            $this->currentIndex
+        ) = end($this->itemStack);
+    }
+
     /**
      * @return array
      */
@@ -390,13 +548,175 @@ protected function getUpIndex()
         return $this->upIndex;
     }
 
-    private function convertScalarToDBField(bool|string|float|int $value): DBField
+    /**
+     * Evaluate a template override. Returns an array where the presence of
+     * a 'value' key indiciates whether an override was successfully found,
+     * as null is a valid override value
+     *
+     * @param string $property Name of override requested
+     * @param array $overrides List of overrides available
+     * @return array An array with a 'value' key if a value has been found, or empty if not
+     */
+    protected function processTemplateOverride($property, $overrides)
     {
-        return match (gettype($value)) {
-            'boolean' => DBBoolean::create()->setValue($value),
-            'string' => DBText::create()->setValue($value),
-            'double' => DBFloat::create()->setValue($value),
-            'integer' => DBInt::create()->setValue($value),
-        };
+        if (!array_key_exists($property, $overrides)) {
+            return [];
+        }
+
+        // Detect override type
+        $override = $overrides[$property];
+
+        // Late-evaluate this value
+        if (!is_string($override) && is_callable($override)) {
+            $override = $override();
+
+            // Late override may yet return null
+            if (!isset($override)) {
+                return [];
+            }
+        }
+
+        return ['value' => $override];
+    }
+
+    /**
+     * Build cache of global properties
+     */
+    protected function cacheGlobalProperties()
+    {
+        if (SSViewer_Scope::$globalProperties !== null) {
+            return;
+        }
+
+        SSViewer_Scope::$globalProperties = $this->getPropertiesFromProvider(
+            TemplateGlobalProvider::class,
+            'get_template_global_variables'
+        );
+    }
+
+    /**
+     * Build cache of global iterator properties
+     */
+    protected function cacheIteratorProperties()
+    {
+        if (SSViewer_Scope::$iteratorProperties !== null) {
+            return;
+        }
+
+        SSViewer_Scope::$iteratorProperties = $this->getPropertiesFromProvider(
+            TemplateIteratorProvider::class,
+            'get_template_iterator_variables',
+            true // Call non-statically
+        );
+    }
+
+    protected function getObj(string $name, array $arguments, string $type): ?ViewLayerData
+    {
+        if ($this->hasOverlay($name)) {
+            return $this->getOverlay($name, $arguments);
+        }
+
+        // @TODO caching
+        $on = $this->getCurrentItem();
+        if ($on && isset($on->$name)) {
+            if ($type === ViewLayerData::TYPE_METHOD) {
+                return $on->$name(...$arguments);
+            }
+            // property
+            return $on->$name;
+        }
+
+        return $this->getUnderlay($name, $arguments);
+    }
+
+    protected function hasOverlay(string $property): bool
+    {
+        $result = $this->processTemplateOverride($property, $this->overlay);
+        return array_key_exists('value', $result);
+    }
+
+    protected function getOverlay(string $property, array $args, bool $getRaw = false): mixed
+    {
+        $result = $this->processTemplateOverride($property, $this->overlay);
+        if (array_key_exists('value', $result)) {
+            return $this->getInjectedValue($result, $property, $args, $getRaw);
+        }
+        return null;
+    }
+
+    protected function getUnderlay(string $property, array $args, bool $getRaw = false): mixed
+    {
+        // Check for a presenter-specific override
+        $result = $this->processTemplateOverride($property, $this->underlay);
+        if (array_key_exists('value', $result)) {
+            return $this->getInjectedValue($result, $property, $args, $getRaw);
+        }
+
+        // Then for iterator-specific overrides
+        if (array_key_exists($property, SSViewer_Scope::$iteratorProperties)) {
+            $source = SSViewer_Scope::$iteratorProperties[$property];
+            /** @var TemplateIteratorProvider $implementor */
+            $implementor = $source['implementor'];
+            if ($this->itemIterator) {
+                // Set the current iterator position and total (the object instance is the first item in
+                // the callable array)
+                $implementor->iteratorProperties(
+                    $this->itemIterator->key(),
+                    $this->itemIteratorTotal
+                );
+            } else {
+                // If we don't actually have an iterator at the moment, act like a list of length 1
+                $implementor->iteratorProperties(0, 1);
+            }
+
+            return $this->getInjectedValue($source, $property, $args, $getRaw);
+        }
+
+        // And finally for global overrides
+        if (array_key_exists($property, SSViewer_Scope::$globalProperties)) {
+            return $this->getInjectedValue(
+                SSViewer_Scope::$globalProperties[$property],
+                $property,
+                $args,
+                $getRaw
+            );
+        }
+
+        return null;
+    }
+
+    protected function getInjectedValue(
+        array|TemplateGlobalProvider|TemplateIteratorProvider $source,
+        string $property,
+        array $params,
+        bool $getRaw = false
+    ) {
+        // Look up the value - either from a callable, or from a directly provided value
+        $value = null;
+        if (isset($source['callable'])) {
+            $value = $source['callable'](...$params);
+        } elseif (array_key_exists('value', $source)) {
+            $value = $source['value'];
+        } else {
+            throw new InvalidArgumentException(
+                "Injected property $property doesn't have a value or callable value source provided"
+            );
+        }
+
+        if ($value === null) {
+            return null;
+        }
+
+        // TemplateGlobalProviders can provide an explicit service to cast to which works outside of the regular cast flow
+        if (!$getRaw && isset($source['casting'])) {
+            $castObject = Injector::inst()->create($source['casting'], $property);
+            if (!ClassInfo::hasMethod($castObject, 'setValue')) {
+                throw new LogicException('Explicit cast from template global provider must have a setValue method.');
+            }
+            $castObject->setValue($value);
+            $value = $castObject;
+        }
+
+        return $getRaw ? $value : ViewLayerData::create($value);
     }
 }
diff --git a/src/View/ViewLayerData.php b/src/View/ViewLayerData.php
new file mode 100644
index 00000000000..85cc55d3572
--- /dev/null
+++ b/src/View/ViewLayerData.php
@@ -0,0 +1,195 @@
+<?php
+
+namespace SilverStripe\View;
+
+use BadMethodCallException;
+use Countable;
+use InvalidArgumentException;
+use IteratorAggregate;
+use SilverStripe\Core\ClassInfo;
+use SilverStripe\Core\Injector\Injectable;
+use SilverStripe\Model\ModelData;
+use Stringable;
+use Traversable;
+
+class ViewLayerData implements IteratorAggregate, Stringable, Countable
+{
+    use Injectable;
+
+    public const TYPE_PROPERTY = 'property';
+
+    public const TYPE_METHOD = 'method';
+
+    private object $data;
+
+    public function __construct(mixed $data, mixed $source = null, string $name = '')
+    {
+        if ($data === null) {
+            throw new InvalidArgumentException('$data must not be null');
+        }
+        if ($data instanceof ViewLayerData) {
+            $data = $data->data;
+        } else {
+            $data = CastingService::singleton()->cast($data, $source, $name);
+        }
+        $this->data = $data;
+    }
+
+    /**
+     * Needed so we can rewind in SSViewer_Scope::next() after getting itemIteratorTotal without throwing an exception.
+     * @TODO see if we can remove the need for this
+     */
+    public function count(): int
+    {
+        if (is_countable($this->data)) {
+            return count($this->data);
+        }
+        if (ClassInfo::hasMethod($this->data, 'getIterator')) {
+            return count($this->data->getIterator());
+        }
+        if (ClassInfo::hasMethod($this->data, 'count')) {
+            return $this->data->count();
+        }
+        if (isset($this->data->count)) {
+            return $this->data->count;
+        }
+        return 0;
+    }
+
+    public function getIterator(): Traversable
+    {
+        if (!is_iterable($this->data) && !ClassInfo::hasMethod($this->data, 'getIterator')) {
+            $type = is_object($this->data) ? get_class($this->data) : gettype($this->data);
+            throw new BadMethodCallException("$type is not iterable.");
+        }
+
+        $iterator = $this->data;
+        if (!is_iterable($iterator)) {
+            $iterator = $this->data->getIterator();
+        }
+        $source = $this->data instanceof ModelData ? $this->data : null;
+        foreach ($iterator as $item) {
+            yield $item === null ? null : ViewLayerData::create($item, $source);
+        }
+    }
+
+    public function __isset(string $name): bool
+    {
+        // Might be worth reintroducing the way ss template engine checks if lists/countables "exist" here,
+        // i.e. if ($this->data->__isset($name) && is_countable($this->data->{$name})) { return count($this->data->{$name}) > 0; }
+        // In worst-case scenarios that would result in lazy-loading a value when we don't need to, but we already do that with the current system.
+
+        // The SS template system uses `ModelData::hasValue()` rather than isset(), but using that doesn't check for methods and we can't use
+        // method_exists on ViewLayerData because the method just simply DOESN'T exist.... so. Hmm.
+        // UPDATE: Added ClassInfo::hasMethod here to simulate what ModelData does... will still have to check if it works with twig
+        // Removing method_exists check in scope for now.
+        return isset($this->data->$name) || ClassInfo::hasMethod($this->data, $name);
+    }
+
+    public function __get(string $name): ?ViewLayerData
+    {
+        $value = $this->getRawDataValue($name, ViewLayerData::TYPE_PROPERTY);
+        if ($value === null) {
+            return null;
+        }
+        $source = $this->data instanceof ModelData ? $this->data : null;
+        return ViewLayerData::create($value, $source, $name); // @TODO maybe not return this here, but wrap it again in the next layer? This may not play nicely with twig when passing values into args?
+    }
+
+    public function __call(string $name, array $arguments = []): ?ViewLayerData
+    {
+        $value = $this->getRawDataValue($name, ViewLayerData::TYPE_METHOD, $arguments);
+        if ($value === null) {
+            return null;
+        }
+        $source = $this->data instanceof ModelData ? $this->data : null;
+        return ViewLayerData::create($value, $source, $name); // @TODO maybe not return this here, but wrap it again in the next layer? This may not play nicely with twig when passing values into args?
+    }
+
+    public function __toString(): string
+    {
+        if ($this->data instanceof ModelData) {
+            return $this->data->forTemplate();
+        }
+        return (string) $this->data;
+    }
+
+    // @TODO We need this right now for the ss template engine, but need to check if
+    // we can rely on it, since twig won't be calling this at all
+    public function hasDataValue(?string $name = null, array $arguments = []): bool
+    {
+        if ($name) {
+            if ($this->data instanceof ModelData) {
+                return $this->data->hasValue($name, $arguments);
+            }
+            return isset($this->$name);
+        }
+        if ($this->data instanceof ModelData) {
+            return $this->data->exists();
+        }
+        return (bool) $this->data;
+    }
+
+    // @TODO We need this right now for the ss template engine, but need to check if
+    // we can rely on it, since twig won't be calling this at all
+    public function getRawDataValue(string $name, string $type, array $arguments = []): mixed
+    {
+        if ($type !== ViewLayerData::TYPE_METHOD && $type !== ViewLayerData::TYPE_PROPERTY) {
+            throw new InvalidArgumentException('$type must be one of the TYPE_* constant values');
+        }
+
+        // Values from ModelData can be cached
+        if ($this->data instanceof ModelData) {
+            $cached = $this->data->objCacheGet($name, $arguments);
+            if ($cached !== null) {
+                return $cached;
+            }
+        }
+
+        $value = null;
+        // Keep track of whether we've already fetched a value (allowing null to be the correct value)
+        $fetchedValue = false;
+
+        // Try a getter before anything else
+        // This matches the "magic" getter behaviour of ModelData across the board for consistent results
+        $getter = "get{$name}";
+        if (ClassInfo::hasMethod($this->data, $getter)) {
+            $value = $this->data->$getter(...$arguments);
+            $fetchedValue = true;
+        }
+
+        // Only try to get a property if we aren't explicitly trying to call a method
+        if (!$fetchedValue && $type === ViewLayerData::TYPE_PROPERTY) {
+            if (isset($this->data->$name)) {
+                $value = $this->data->$name;
+                $fetchedValue = true;
+            }
+        }
+
+        // Fall back on calling a method even if we're fetching as a property
+        if (!$fetchedValue) {
+            // Get value from the method, if there is one
+            $hasMethod = ClassInfo::hasMethod($this->data, $name);
+            $dynamicMethods = !$hasMethod && method_exists($this->data, '__call');
+            if ($hasMethod || $dynamicMethods) {
+                try {
+                    $value = $this->data->$name(...$arguments);
+                } catch (BadMethodCallException $e) {
+                    // Only throw the exception if we weren't relying on __call
+                    // It's common for __call to throw BadMethodCallException for methods that aren't "implemented"
+                    // so we just want to return null in those cases.
+                    if (!$dynamicMethods) {
+                        throw $e;
+                    }
+                }
+            }
+        }
+
+        // Caching for modeldata
+        if ($this->data instanceof ModelData) {
+            $this->data->objCacheSet($name, $arguments, $value);
+        }
+
+        return $value;
+    }
+}
diff --git a/templates/RightLabelledFieldHolder.ss b/templates/RightLabelledFieldHolder.ss
index 574ab26d429..2572b0fe9ee 100644
--- a/templates/RightLabelledFieldHolder.ss
+++ b/templates/RightLabelledFieldHolder.ss
@@ -1,5 +1,5 @@
 <p id="$Name" class="field $Type">
-	$Field
+	$renderField
 	<label class="right" for="$id">$Title</label>
 	<% if $Message %><span class="message $MessageType">$Message</span><% end_if %>
 </p>
diff --git a/templates/SilverStripe/Forms/CheckboxField_holder.ss b/templates/SilverStripe/Forms/CheckboxField_holder.ss
index 1114073b7d9..a490ab22fdf 100644
--- a/templates/SilverStripe/Forms/CheckboxField_holder.ss
+++ b/templates/SilverStripe/Forms/CheckboxField_holder.ss
@@ -1,5 +1,5 @@
 <div id="$HolderID" class="field<% if extraClass %> $extraClass<% end_if %>">
-	$Field
+	$renderField
     <label class="right" for="$ID">$Title<% if $RightTitle %> $RightTitle<% end_if %></label>
 	<% if $Message %><span class="message $MessageType">$Message</span><% end_if %>
 	<% if $Description %><span class="description">$Description</span><% end_if %>
diff --git a/templates/SilverStripe/Forms/CheckboxField_holder_small.ss b/templates/SilverStripe/Forms/CheckboxField_holder_small.ss
index 5d5c19e7327..1c006dedf30 100644
--- a/templates/SilverStripe/Forms/CheckboxField_holder_small.ss
+++ b/templates/SilverStripe/Forms/CheckboxField_holder_small.ss
@@ -1,4 +1,4 @@
-$Field
+$renderField
 
 <% if $Title %>
 	<label class="checkboxfield-small" <% if $ID %>for="$ID"<% end_if %>>$Title<% if $RightTitle %> $RightTitle<% end_if %></label>
diff --git a/templates/SilverStripe/Forms/CompositeField.ss b/templates/SilverStripe/Forms/CompositeField.ss
index 3a42cd04266..86ec3a36dd4 100644
--- a/templates/SilverStripe/Forms/CompositeField.ss
+++ b/templates/SilverStripe/Forms/CompositeField.ss
@@ -1,9 +1,9 @@
 <% loop $FieldList %>
 	<% if $Up.ColumnCount %>
 		<div class="column-{$Up.ColumnCount} $FirstLast">
-			$FieldHolder
+			$renderFieldHolder
 		</div>
 	<% else %>
-		$FieldHolder
+		$renderFieldHolder
 	<% end_if %>
 <% end_loop %>
diff --git a/templates/SilverStripe/Forms/CompositeField_holder.ss b/templates/SilverStripe/Forms/CompositeField_holder.ss
index 9cb6a0f0603..0e096e9659c 100644
--- a/templates/SilverStripe/Forms/CompositeField_holder.ss
+++ b/templates/SilverStripe/Forms/CompositeField_holder.ss
@@ -3,5 +3,5 @@
 		<legend>$Legend</legend>
 	<% end_if %>
 
-	$Field
+	$renderField
 </$Tag>
diff --git a/templates/SilverStripe/Forms/CompositeField_holder_small.ss b/templates/SilverStripe/Forms/CompositeField_holder_small.ss
index c7b433f1372..9e4f2cb2ad3 100644
--- a/templates/SilverStripe/Forms/CompositeField_holder_small.ss
+++ b/templates/SilverStripe/Forms/CompositeField_holder_small.ss
@@ -6,10 +6,10 @@
 	<% loop $FieldList %>
 		<% if $Up.ColumnCount %>
 			<div class="column-{$Up.ColumnCount} $FirstLast">
-				$SmallFieldHolder
+				$renderSmallFieldHolder
 			</div>
 		<% else %>
-			$SmallFieldHolder
+			$renderSmallFieldHolder
 		<% end_if %>
 	<% end_loop %>
 </$Tag>
diff --git a/templates/SilverStripe/Forms/FieldGroup.ss b/templates/SilverStripe/Forms/FieldGroup.ss
index c9b6eb94ad9..b3805f9cf2a 100644
--- a/templates/SilverStripe/Forms/FieldGroup.ss
+++ b/templates/SilverStripe/Forms/FieldGroup.ss
@@ -1,7 +1,7 @@
 <div class="<% if $extraClass %>$extraClass<% else %>fieldgroup<% end_if %><% if $Zebra %> fieldgroup-zebra<% end_if %>" <% if $ID %>id="$ID"<% end_if %>>
 	<% loop $FieldList %>
 		<div class="fieldgroup-field $FirstLast $EvenOdd">
-			$SmallFieldHolder
+			$renderSmallFieldHolder
 		</div>
 	<% end_loop %>
 </div>
diff --git a/templates/SilverStripe/Forms/FieldGroup_DefaultFieldHolder.ss b/templates/SilverStripe/Forms/FieldGroup_DefaultFieldHolder.ss
index 5a1558e69d9..f2211decb35 100644
--- a/templates/SilverStripe/Forms/FieldGroup_DefaultFieldHolder.ss
+++ b/templates/SilverStripe/Forms/FieldGroup_DefaultFieldHolder.ss
@@ -1,7 +1,7 @@
 <div class="<% if $extraClass %>$extraClass<% else %>fieldgroup<% end_if %><% if $Zebra %> fieldgroup-zebra<% end_if %>" <% if ID %>id="$ID"<% end_if %>>
 	<% loop $FieldList %>
 		<div class="fieldgroup-field $FirstLast $EvenOdd">
-			$FieldHolder
+			$renderFieldHolder
 		</div>
 	<% end_loop %>
 </div>
diff --git a/templates/SilverStripe/Forms/FieldGroup_holder.ss b/templates/SilverStripe/Forms/FieldGroup_holder.ss
index 19b45bb1689..98a799985fd 100644
--- a/templates/SilverStripe/Forms/FieldGroup_holder.ss
+++ b/templates/SilverStripe/Forms/FieldGroup_holder.ss
@@ -4,7 +4,7 @@
 	<div class="middleColumn fieldgroup<% if $Zebra %> fieldgroup-$Zebra<% end_if %>">
 		<% loop $FieldList %>
 			<div class="fieldgroup-field $FirstLast $EvenOdd">
-				$SmallFieldHolder
+				$renderSmallFieldHolder
 			</div>
 		<% end_loop %>
 	</div>
diff --git a/templates/SilverStripe/Forms/FormField_holder.ss b/templates/SilverStripe/Forms/FormField_holder.ss
index df878d9ac4f..767c1282c33 100644
--- a/templates/SilverStripe/Forms/FormField_holder.ss
+++ b/templates/SilverStripe/Forms/FormField_holder.ss
@@ -1,7 +1,7 @@
 <div id="$HolderID" class="field<% if $extraClass %> $extraClass<% end_if %>">
 	<% if $Title %><label class="left" for="$ID">$Title</label><% end_if %>
 	<div class="middleColumn">
-		$Field
+		$renderField
 	</div>
 	<% if $RightTitle %><label class="right" for="$ID">$RightTitle</label><% end_if %>
 	<% if $Message %><span class="message $MessageType">$Message</span><% end_if %>
diff --git a/templates/SilverStripe/Forms/FormField_holder_small.ss b/templates/SilverStripe/Forms/FormField_holder_small.ss
index 15b3280d573..8a6e981e8d2 100644
--- a/templates/SilverStripe/Forms/FormField_holder_small.ss
+++ b/templates/SilverStripe/Forms/FormField_holder_small.ss
@@ -1,5 +1,5 @@
 <div class="fieldholder-small<% if $extraClass %> $extraClass<% end_if %>" id="$HolderID.ATT">
 	<% if $Title %><label class="fieldholder-small-label" <% if $ID %>for="$ID"<% end_if %>>$Title</label><% end_if %>
-	$Field
+	$renderField
 	<% if $RightTitle %><label class="right fieldholder-small-label" <% if $ID %>for="$ID"<% end_if %>>$RightTitle</label><% end_if %>
 </div>
diff --git a/templates/SilverStripe/Forms/GridField/GridFieldAddExistingAutocompleter.ss b/templates/SilverStripe/Forms/GridField/GridFieldAddExistingAutocompleter.ss
index cdf9e1daba1..6b08ba0810d 100644
--- a/templates/SilverStripe/Forms/GridField/GridFieldAddExistingAutocompleter.ss
+++ b/templates/SilverStripe/Forms/GridField/GridFieldAddExistingAutocompleter.ss
@@ -1,5 +1,5 @@
 <div class="add-existing-autocompleter">
 	<% loop $Fields %>
-	<span>$Field</span>
+	<span>$renderField</span>
 	<% end_loop %>
 </div>
diff --git a/templates/SilverStripe/Forms/GridField/GridFieldFilterHeader_Row.ss b/templates/SilverStripe/Forms/GridField/GridFieldFilterHeader_Row.ss
index bed1ebf5dd8..e8f63be314c 100644
--- a/templates/SilverStripe/Forms/GridField/GridFieldFilterHeader_Row.ss
+++ b/templates/SilverStripe/Forms/GridField/GridFieldFilterHeader_Row.ss
@@ -1,7 +1,7 @@
 <% if $Fields %>
     <tr class="grid-field__filter-header grid-field__search-holder--hidden">
 	   <% loop $Fields %>
-	       <th class="extra">$Field</th>
+	       <th class="extra">$renderField</th>
 	   <% end_loop %>
     </tr>
 <% end_if %>
diff --git a/templates/SilverStripe/Forms/GridField/GridFieldSortableHeader_Row.ss b/templates/SilverStripe/Forms/GridField/GridFieldSortableHeader_Row.ss
index 2b12b728a8e..17242d8da33 100644
--- a/templates/SilverStripe/Forms/GridField/GridFieldSortableHeader_Row.ss
+++ b/templates/SilverStripe/Forms/GridField/GridFieldSortableHeader_Row.ss
@@ -1,5 +1,5 @@
 <tr class="sortable-header">
 	<% loop $Fields %>
-		<th class="main col-$getName">$Field</th>
+		<th class="main col-$getName">$renderField</th>
 	<% end_loop %>
 </tr>
diff --git a/templates/SilverStripe/Forms/HTMLEditor/HTMLEditorField_Toolbar_viewfile.ss b/templates/SilverStripe/Forms/HTMLEditor/HTMLEditorField_Toolbar_viewfile.ss
index b7661c84967..6def1325010 100644
--- a/templates/SilverStripe/Forms/HTMLEditor/HTMLEditorField_Toolbar_viewfile.ss
+++ b/templates/SilverStripe/Forms/HTMLEditor/HTMLEditorField_Toolbar_viewfile.ss
@@ -40,7 +40,7 @@
 		<div class="details ss-uploadfield-item-editform">
 			<fieldset>
 				<% loop $Fields %>
-					$FieldHolder
+					$renderFieldHolder
 				<% end_loop %>
 			</fieldset>
 		</div>
diff --git a/templates/SilverStripe/Forms/Includes/Form.ss b/templates/SilverStripe/Forms/Includes/Form.ss
index caee5ad7685..08fd1809995 100644
--- a/templates/SilverStripe/Forms/Includes/Form.ss
+++ b/templates/SilverStripe/Forms/Includes/Form.ss
@@ -10,7 +10,7 @@
 	<fieldset>
 		<% if $Legend %><legend>$Legend</legend><% end_if %>
 		<% loop $Fields %>
-			$FieldHolder
+			$renderFieldHolder
 		<% end_loop %>
 		<div class="clear"><!-- --></div>
 	</fieldset>
@@ -18,7 +18,7 @@
 	<% if $Actions %>
 	<div class="btn-toolbar">
 		<% loop $Actions %>
-			$Field
+			$renderField
 		<% end_loop %>
 	</div>
 	<% end_if %>
diff --git a/templates/SilverStripe/Forms/OptionsetField_holder.ss b/templates/SilverStripe/Forms/OptionsetField_holder.ss
index dd566be383f..a5476e0e6c0 100644
--- a/templates/SilverStripe/Forms/OptionsetField_holder.ss
+++ b/templates/SilverStripe/Forms/OptionsetField_holder.ss
@@ -1,7 +1,7 @@
 <div id="$HolderID" class="field<% if $extraClass %> $extraClass<% end_if %>">
 	<% if $Title %><label class="left">$Title</label><% end_if %>
 	<div class="middleColumn">
-		$Field
+		$renderField
 	</div>
 	<% if $RightTitle %><label class="right">$RightTitle</label><% end_if %>
 	<% if $Message %><span class="message $MessageType">$Message</span><% end_if %>
diff --git a/templates/SilverStripe/Security/MemberAuthenticator/Includes/CMSMemberLoginForm.ss b/templates/SilverStripe/Security/MemberAuthenticator/Includes/CMSMemberLoginForm.ss
index 319a9bf500f..fbdc42a2cf9 100644
--- a/templates/SilverStripe/Security/MemberAuthenticator/Includes/CMSMemberLoginForm.ss
+++ b/templates/SilverStripe/Security/MemberAuthenticator/Includes/CMSMemberLoginForm.ss
@@ -4,7 +4,7 @@
 	<fieldset>
 		<% if $Legend %><legend>$Legend</legend><% end_if %>
 		<% loop $Fields %>
-			$FieldHolder
+			$renderFieldHolder
 		<% end_loop %>
 		<div class="clear"><!-- --></div>
 	</fieldset>
@@ -12,7 +12,7 @@
 	<% if $Actions %>
 	<div class="btn-toolbar">
 		<% loop $Actions %>
-			$Field
+			$renderField
 		<% end_loop %>
 	</div>
 	<% end_if %>
diff --git a/templates/forms/HtmlEditorField_holder_small.ss b/templates/forms/HtmlEditorField_holder_small.ss
index 21eec8dc53d..de708d313f0 100644
--- a/templates/forms/HtmlEditorField_holder_small.ss
+++ b/templates/forms/HtmlEditorField_holder_small.ss
@@ -1,5 +1,5 @@
 <div class="fieldholder-small field htmleditor">
     <% if $Title %><label class="fieldholder-small-label" <% if $ID %>for="$ID"<% end_if %>>$Title</label><% end_if %>
-    $Field
+    $renderField
     <% if $RightTitle %><label class="right fieldholder-small-label" <% if $ID %>for="$ID"<% end_if %>>$RightTitle</label><% end_if %>
 </div>
diff --git a/tests/php/Forms/CheckboxFieldTest.php b/tests/php/Forms/CheckboxFieldTest.php
index 0ac43df3628..a7efa97e853 100644
--- a/tests/php/Forms/CheckboxFieldTest.php
+++ b/tests/php/Forms/CheckboxFieldTest.php
@@ -141,7 +141,7 @@ public function testReadonlyCheckboxField()
         $field1->setValue('on');
         $this->assertEquals(
             _t('SilverStripe\\Forms\\CheckboxField.YESANSWER', 'Yes'),
-            trim(strip_tags($field1->performReadonlyTransformation()->Field() ?? ''))
+            trim(strip_tags($field1->performReadonlyTransformation()->renderField() ?? ''))
         );
 
         // Test 2: an checkbox with the value set to false to "No"
@@ -149,14 +149,14 @@ public function testReadonlyCheckboxField()
         $field2->setValue(false);
         $this->assertEquals(
             _t('SilverStripe\\Forms\\CheckboxField.NOANSWER', 'No'),
-            trim(strip_tags($field2->performReadonlyTransformation()->Field() ?? ''))
+            trim(strip_tags($field2->performReadonlyTransformation()->renderField() ?? ''))
         );
 
         // Test 3: an checkbox with no value ever set goes to "No"
         $field3 = new CheckboxField('IsChecked', 'Checked');
         $this->assertEquals(
             _t('SilverStripe\\Forms\\CheckboxField.NOANSWER', 'No'),
-            trim(strip_tags($field3->performReadonlyTransformation()->Field() ?? ''))
+            trim(strip_tags($field3->performReadonlyTransformation()->renderField() ?? ''))
         );
     }
 
diff --git a/tests/php/Forms/CheckboxSetFieldTest.php b/tests/php/Forms/CheckboxSetFieldTest.php
index ff85da49474..12a11dab9d4 100644
--- a/tests/php/Forms/CheckboxSetFieldTest.php
+++ b/tests/php/Forms/CheckboxSetFieldTest.php
@@ -38,7 +38,7 @@ public function testSetDefaultItems()
 
         $f->setValue([0,1]);
         $f->setDefaultItems([2]);
-        $p = new CSSContentParser($f->Field());
+        $p = new CSSContentParser($f->renderField());
         $item0 = $p->getBySelector('#Test_0');
         $item1 = $p->getBySelector('#Test_1');
         $item2 = $p->getBySelector('#Test_2');
@@ -357,7 +357,7 @@ public function testSafelyCast()
             'four' => $member->FirstName,
             ]
         );
-        $fieldHTML = (string)$field1->Field();
+        $fieldHTML = (string)$field1->renderField();
         $this->assertStringContainsString('One', $fieldHTML);
         $this->assertStringContainsString('Two &amp; Three', $fieldHTML);
         $this->assertStringNotContainsString('Two & Three', $fieldHTML);
diff --git a/tests/php/Forms/CompositeFieldTest.php b/tests/php/Forms/CompositeFieldTest.php
index cff078dc2b5..0afd5bc9fe1 100644
--- a/tests/php/Forms/CompositeFieldTest.php
+++ b/tests/php/Forms/CompositeFieldTest.php
@@ -47,14 +47,14 @@ public function testTag()
             new TextField('A'),
             new TextField('B')
         );
-        $this->assertStringStartsWith('<div', trim($div->FieldHolder() ?? ''));
-        $this->assertStringEndsWith('/div>', trim($div->FieldHolder() ?? ''));
+        $this->assertStringStartsWith('<div', trim($div->renderFieldHolder() ?? ''));
+        $this->assertStringEndsWith('/div>', trim($div->renderFieldHolder() ?? ''));
 
         $fieldset = new CompositeField();
         $fieldset->setTag('fieldset');
 
-        $this->assertStringStartsWith('<fieldset', trim($fieldset->FieldHolder() ?? ''));
-        $this->assertStringEndsWith('/fieldset>', trim($fieldset->FieldHolder() ?? ''));
+        $this->assertStringStartsWith('<fieldset', trim($fieldset->renderFieldHolder() ?? ''));
+        $this->assertStringEndsWith('/fieldset>', trim($fieldset->renderFieldHolder() ?? ''));
     }
 
     public function testPushAndUnshift()
@@ -86,7 +86,7 @@ public function testLegend()
         $composite->setTag('fieldset');
         $composite->setLegend('My legend');
 
-        $parser = new CSSContentParser($composite->FieldHolder());
+        $parser = new CSSContentParser($composite->renderFieldHolder());
         $root = $parser->getBySelector('fieldset.composite');
         $legend = $parser->getBySelector('fieldset.composite legend');
 
diff --git a/tests/php/Forms/ConfirmedPasswordFieldTest.php b/tests/php/Forms/ConfirmedPasswordFieldTest.php
index db2aed70507..8e305f947cf 100644
--- a/tests/php/Forms/ConfirmedPasswordFieldTest.php
+++ b/tests/php/Forms/ConfirmedPasswordFieldTest.php
@@ -72,7 +72,7 @@ public function testSetShowOnClick()
     {
         //hide by default and display show/hide toggle button
         $field = new ConfirmedPasswordField('Test', 'Testing', 'valueA', null, true);
-        $fieldHTML = $field->Field();
+        $fieldHTML = $field->renderField();
         $this->assertStringContainsString(
             "showOnClickContainer",
             $fieldHTML,
@@ -86,7 +86,7 @@ public function testSetShowOnClick()
 
         //show all by default
         $field = new ConfirmedPasswordField('Test', 'Testing', 'valueA', null, false);
-        $fieldHTML = $field->Field();
+        $fieldHTML = $field->renderField();
         $this->assertStringNotContainsString(
             "showOnClickContainer",
             $fieldHTML,
@@ -502,7 +502,7 @@ public function testChildFieldsAreRequired(bool $canBeEmpty, bool $required, boo
             }
             $form->setValidator(new RequiredFields($requiredFields));
 
-            $rendered = $field->Field();
+            $rendered = $field->renderField();
             $fieldOneRegex = '<input\s+type="password"\s+name="Test\[_Password\]"\s[^>]*?required="required"\s+aria-required="true"\s[^>]*\/>';
             $fieldTwoRegex = '<input\s+type="password"\s+name="Test\[_ConfirmPassword\]"\s[^>]*?required="required"\s+aria-required="true"\s[^>]*\/>';
             $regex = '/' . $fieldOneRegex . '.*' . $fieldTwoRegex . '/isu';
diff --git a/tests/php/Forms/CurrencyFieldDisabledTest.php b/tests/php/Forms/CurrencyFieldDisabledTest.php
index ed9c8c5ac65..104b1ee9b36 100644
--- a/tests/php/Forms/CurrencyFieldDisabledTest.php
+++ b/tests/php/Forms/CurrencyFieldDisabledTest.php
@@ -11,7 +11,7 @@ class CurrencyFieldDisabledTest extends SapphireTest
     public function testFieldWithValue()
     {
         $field = new CurrencyField_Disabled('Test', '', '$5.00');
-        $result = $field->Field();
+        $result = $field->renderField();
 
         $this->assertStringContainsString('<input', $result, 'An input should be rendered');
         $this->assertStringContainsString('disabled', $result, 'The input should be disabled');
@@ -22,7 +22,7 @@ public function testFieldWithCustomisedCurrencySymbol()
     {
         DBCurrency::config()->set('currency_symbol', '€');
         $field = new CurrencyField_Disabled('Test', '', '€5.00');
-        $result = $field->Field();
+        $result = $field->renderField();
 
         $this->assertStringContainsString('<input', $result, 'An input should be rendered');
         $this->assertStringContainsString('disabled', $result, 'The input should be disabled');
diff --git a/tests/php/Forms/CurrencyFieldReadonlyTest.php b/tests/php/Forms/CurrencyFieldReadonlyTest.php
index 7850a79f550..52f011060dd 100644
--- a/tests/php/Forms/CurrencyFieldReadonlyTest.php
+++ b/tests/php/Forms/CurrencyFieldReadonlyTest.php
@@ -19,7 +19,7 @@ public function testPerformReadonlyTransformation()
     public function testFieldWithValue()
     {
         $field = new CurrencyField_Readonly('Test', '', '$5.00');
-        $result = $field->Field();
+        $result = $field->renderField();
 
         $this->assertStringContainsString('<input', $result, 'An input should be rendered');
         $this->assertStringContainsString('readonly', $result, 'The input should be readonly');
@@ -30,7 +30,7 @@ public function testFieldWithOutValue()
     {
         DBCurrency::config()->set('currency_symbol', 'AUD');
         $field = new CurrencyField_Readonly('Test', '', null);
-        $result = $field->Field();
+        $result = $field->renderField();
 
         $this->assertStringContainsString('<input', $result, 'An input should be rendered');
         $this->assertStringContainsString('readonly', $result, 'The input should be readonly');
@@ -41,7 +41,7 @@ public function testFieldWithCustomisedCurrencySymbol()
     {
         DBCurrency::config()->set('currency_symbol', '€');
         $field = new CurrencyField_Readonly('Test', '', '€5.00');
-        $result = $field->Field();
+        $result = $field->renderField();
 
         $this->assertStringContainsString('<input', $result, 'An input should be rendered');
         $this->assertStringContainsString('readonly', $result, 'The input should be readonly');
diff --git a/tests/php/Forms/DatalessFieldTest.php b/tests/php/Forms/DatalessFieldTest.php
index cd7c86cebe6..c3ab4b09ef8 100644
--- a/tests/php/Forms/DatalessFieldTest.php
+++ b/tests/php/Forms/DatalessFieldTest.php
@@ -19,17 +19,17 @@ public function testFieldHolderAndSmallFieldHolderReturnField()
         /** @var DatalessField|MockObject $mock */
         $mock = $this->getMockBuilder(DatalessField::class)
             ->disableOriginalConstructor()
-            ->onlyMethods(['Field'])
+            ->onlyMethods(['renderField'])
             ->getMock();
 
         $properties = [
             'foo' => 'bar',
         ];
 
-        $mock->expects($this->exactly(2))->method('Field')->with($properties)->willReturn('boo!');
+        $mock->expects($this->exactly(2))->method('renderField')->with($properties)->willReturn('boo!');
 
-        $fieldHolder = $mock->FieldHolder($properties);
-        $smallFieldHolder = $mock->SmallFieldHolder($properties);
+        $fieldHolder = $mock->renderFieldHolder($properties);
+        $smallFieldHolder = $mock->renderSmallFieldHolder($properties);
 
         $this->assertSame('boo!', $fieldHolder);
         $this->assertSame('boo!', $smallFieldHolder);
diff --git a/tests/php/Forms/DateFieldDisabledTest.php b/tests/php/Forms/DateFieldDisabledTest.php
index 3cb107b183c..7bab49b4199 100644
--- a/tests/php/Forms/DateFieldDisabledTest.php
+++ b/tests/php/Forms/DateFieldDisabledTest.php
@@ -22,14 +22,14 @@ public function testFieldToday()
         // Today date with normal local
         $actual = DateField_Disabled::create('Test')
             ->setValue('2011-02-01')
-            ->Field();
+            ->renderField();
         $expected = '<span class="readonly" id="Test">Feb 1, 2011 (today)</span>';
         $this->assertEquals($expected, $actual);
 
         // Test today's date with time
         $actual = DateField_Disabled::create('Test')
             ->setValue('2011-02-01 10:34:00')
-            ->Field();
+            ->renderField();
         $this->assertEquals($expected, $actual);
     }
 
@@ -38,14 +38,14 @@ public function testFieldWithDifferentDay()
         // Test past
         $actual = DateField_Disabled::create('Test')
             ->setValue('2011-01-27')
-            ->Field();
+            ->renderField();
         $expected = '<span class="readonly" id="Test">Jan 27, 2011, 5 days ago</span>';
         $this->assertEquals($expected, $actual);
 
         // Test future
         $actual = DateField_Disabled::create('Test')
             ->setValue('2011-02-06')
-            ->Field();
+            ->renderField();
         $expected = '<span class="readonly" id="Test">Feb 6, 2011, in 5 days</span>';
         $this->assertEquals($expected, $actual);
     }
@@ -57,7 +57,7 @@ public function testFieldWithDifferentLocal()
             ->setValue('2011-02-06')
             ->setHTML5(false)
             ->setLocale('de_DE')
-            ->Field();
+            ->renderField();
         $expected = '<span class="readonly" id="Test">06.02.2011, in 5 days</span>';
         $this->assertEquals($expected, $actual);
     }
@@ -65,11 +65,11 @@ public function testFieldWithDifferentLocal()
     public function testFieldWithNonValue()
     {
         // Test none value
-        $actual = DateField_Disabled::create('Test')->Field();
+        $actual = DateField_Disabled::create('Test')->renderField();
         $expected = '<span class="readonly" id="Test"><i>(not set)</i></span>';
         $this->assertEquals($expected, $actual);
 
-        $actual = DateField_Disabled::create('Test')->setValue('This is not a date')->Field();
+        $actual = DateField_Disabled::create('Test')->setValue('This is not a date')->renderField();
         $this->assertEquals($expected, $actual);
     }
 
diff --git a/tests/php/Forms/DropdownFieldTest.php b/tests/php/Forms/DropdownFieldTest.php
index 8230348a79c..c8a0910e767 100644
--- a/tests/php/Forms/DropdownFieldTest.php
+++ b/tests/php/Forms/DropdownFieldTest.php
@@ -103,7 +103,7 @@ public function testReadonlyField()
         $field->setEmptyString('(Select one)');
         $field->setValue(1);
         $readonlyField = $field->performReadonlyTransformation();
-        preg_match('/Yes/', $field->Field() ?? '', $matches);
+        preg_match('/Yes/', $field->renderField() ?? '', $matches);
         $this->assertEquals($matches[0], 'Yes');
     }
 
@@ -123,7 +123,7 @@ public function testHasEmptyDefault()
         );
 
         // Test that an empty option comes through in the markup however
-        $options = $this->findOptionElements($field->Field());
+        $options = $this->findOptionElements($field->renderField());
 
         $this->assertEquals(
             2,
@@ -151,7 +151,7 @@ public function testHasEmptyDefault()
         );
 
         // Test that an empty option does not comes through in the markup however
-        $options = $this->findOptionElements($FieldWithoutEmpty->Field());
+        $options = $this->findOptionElements($FieldWithoutEmpty->renderField());
 
         $this->assertEquals(
             1,
@@ -234,7 +234,7 @@ public function testZeroArraySourceNotOverwrittenByEmptyString()
             ]
         );
 
-        $options = $this->findOptionElements($field->Field());
+        $options = $this->findOptionElements($field->renderField());
 
         $this->assertEquals(
             2,
@@ -257,7 +257,7 @@ public function testStringZeroValueSelectedOptionBehaviour()
             '0'
         );
 
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], 'none', 'The selected option is "none"');
 
         $field = new DropdownField(
@@ -272,7 +272,7 @@ public function testStringZeroValueSelectedOptionBehaviour()
             0
         );
 
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], 'none', 'The selected option is "none"');
     }
 
@@ -291,7 +291,7 @@ public function testStringOneValueSelectedOptionBehaviour()
         );
 
 
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], 'one', 'The selected option is "one"');
 
         $field = new DropdownField(
@@ -306,7 +306,7 @@ public function testStringOneValueSelectedOptionBehaviour()
             1
         );
 
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], 'one', 'The selected option is "one"');
     }
 
@@ -316,8 +316,8 @@ public function testNumberOfSelectOptionsAvailable()
         $field = $this->createDropdownField('(Any)');
 
         /* 3 options are available */
-        $this->assertEquals(count($this->findOptionElements($field->Field()) ?? []), 3, '3 options are available');
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $this->assertEquals(count($this->findOptionElements($field->renderField()) ?? []), 3, '3 options are available');
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals(
             count($selectedOptions ?? []),
             1,
@@ -328,36 +328,36 @@ public function testNumberOfSelectOptionsAvailable()
         $field = $this->createDropdownField();
 
         /* 2 options are available */
-        $this->assertEquals(count($this->findOptionElements($field->Field()) ?? []), 2, '2 options are available');
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $this->assertEquals(count($this->findOptionElements($field->renderField()) ?? []), 2, '2 options are available');
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals(count($selectedOptions ?? []), 0, 'There are no selected options');
     }
 
     public function testIntegerZeroValueSeelctedOptionBehaviour()
     {
         $field = $this->createDropdownField('(Any)', 0);
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], 'No', 'The selected option is "No"');
     }
 
     public function testBlankStringValueSelectedOptionBehaviour()
     {
         $field = $this->createDropdownField('(Any)');
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], '(Any)', 'The selected option is "(Any)"');
     }
 
     public function testNullValueSelectedOptionBehaviour()
     {
         $field = $this->createDropdownField('(Any)', null);
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], '(Any)', 'The selected option is "(Any)"');
     }
 
     public function testStringValueSelectedOptionBehaviour()
     {
         $field = $this->createDropdownField('(Any)', '1');
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals((string) $selectedOptions[0], 'Yes', 'The selected option is "Yes"');
         $field->setSource(
             [
@@ -366,7 +366,7 @@ public function testStringValueSelectedOptionBehaviour()
             ]
         );
         $field->setValue('Cats');
-        $selectedOptions = $this->findSelectedOptionElements($field->Field());
+        $selectedOptions = $this->findSelectedOptionElements($field->renderField());
         $this->assertEquals(
             (string) $selectedOptions[0],
             'Cats and Kittens',
@@ -381,10 +381,10 @@ public function testNumberOfDisabledOptions()
         $field->setDisabledItems([0,1]);
 
         /* 3 options are available */
-        $this->assertEquals(count($this->findOptionElements($field->Field()) ?? []), 3, '3 options are available');
+        $this->assertEquals(count($this->findOptionElements($field->renderField()) ?? []), 3, '3 options are available');
 
         /* There are 2 disabled options */
-        $disabledOptions = $this->findDisabledOptionElements($field->Field());
+        $disabledOptions = $this->findDisabledOptionElements($field->renderField());
         $this->assertEquals(count($disabledOptions ?? []), 2, 'We have 2 disabled options');
 
         /* Create a field without a blank value & set 1 to disabled, then set none to disabled (unset) */
@@ -392,7 +392,7 @@ public function testNumberOfDisabledOptions()
         $field->setDisabledItems([1]);
 
         /* 2 options are available */
-        $this->assertEquals(count($this->findOptionElements($field->Field()) ?? []), 2, '2 options are available');
+        $this->assertEquals(count($this->findOptionElements($field->renderField()) ?? []), 2, '2 options are available');
 
         /* get disabled items returns an array of one */
         $this->assertEquals(
@@ -404,7 +404,7 @@ public function testNumberOfDisabledOptions()
         $field->setDisabledItems([]);
 
         /* There are no disabled options anymore */
-        $disabledOptions = $this->findDisabledOptionElements($field->Field());
+        $disabledOptions = $this->findDisabledOptionElements($field->renderField());
         $this->assertEquals(count($disabledOptions ?? []), 0, 'There are no disabled options');
     }
 
@@ -417,7 +417,7 @@ public function testDropdownWithArrayValues($value)
     {
         $field = $this->createDropdownField();
         $field->setValue($value);
-        $this->assertInstanceOf('SilverStripe\\ORM\\FieldType\\DBHTMLText', $field->Field());
+        $this->assertInstanceOf('SilverStripe\\ORM\\FieldType\\DBHTMLText', $field->renderField());
         $this->assertSame($value, $field->Value());
     }
 
diff --git a/tests/php/Forms/FieldListTest.php b/tests/php/Forms/FieldListTest.php
index ef7c4f6277c..a82eddd4bdc 100644
--- a/tests/php/Forms/FieldListTest.php
+++ b/tests/php/Forms/FieldListTest.php
@@ -1122,7 +1122,7 @@ public function testForTemplate()
             $b = new TextField('B')
         );
 
-        $this->assertEquals($a->FieldHolder() . $b->FieldHolder(), $set->forTemplate());
+        $this->assertEquals($a->renderFieldHolder() . $b->renderFieldHolder(), $set->forTemplate());
     }
 
     /**
@@ -1137,7 +1137,7 @@ public function testForTemplateForActionList()
             $b = new FormAction('B')
         );
 
-        $this->assertEquals($a->Field() . $b->Field(), $set->forTemplate());
+        $this->assertEquals($a->renderField() . $b->renderField(), $set->forTemplate());
     }
 
     public function testMakeFieldReadonly()
diff --git a/tests/php/Forms/GridField/GridFieldActionMenuTest.php b/tests/php/Forms/GridField/GridFieldActionMenuTest.php
index 2e8c5e43756..6689f2bde10 100644
--- a/tests/php/Forms/GridField/GridFieldActionMenuTest.php
+++ b/tests/php/Forms/GridField/GridFieldActionMenuTest.php
@@ -73,7 +73,7 @@ public function testShowActionMenu()
             Security::setCurrentUser(null);
         }
 
-        $content = new CSSContentParser($this->gridField->FieldHolder());
+        $content = new CSSContentParser($this->gridField->renderFieldHolder());
         // Check that there are content
         $this->assertEquals(4, count($content->getBySelector('.ss-gridfield-item') ?? []));
         // Make sure that there are edit links, even though the user doesn't have "edit" permissions
@@ -124,7 +124,7 @@ public function testHiddenActionMenuItems()
     public function testShowEditLinksWithAdminPermission()
     {
         $this->logInWithPermission('ADMIN');
-        $content = new CSSContentParser($this->gridField->FieldHolder());
+        $content = new CSSContentParser($this->gridField->renderFieldHolder());
         $editLinks = $content->getBySelector('.gridfield-actionmenu__container');
         $this->assertEquals(3, count($editLinks ?? []), 'Edit links should show when logged in.');
     }
diff --git a/tests/php/Forms/GridField/GridFieldDeleteActionTest.php b/tests/php/Forms/GridField/GridFieldDeleteActionTest.php
index 63627f2246b..c80c53e7169 100644
--- a/tests/php/Forms/GridField/GridFieldDeleteActionTest.php
+++ b/tests/php/Forms/GridField/GridFieldDeleteActionTest.php
@@ -75,7 +75,7 @@ public function testDontShowDeleteButtons()
         if (Security::getCurrentUser()) {
             Security::setCurrentUser(null);
         }
-        $content = new CSSContentParser($this->gridField->FieldHolder());
+        $content = new CSSContentParser($this->gridField->renderFieldHolder());
         // Check that there are content
         $this->assertEquals(4, count($content->getBySelector('.ss-gridfield-item') ?? []));
         // Make sure that there are no delete buttons
@@ -89,7 +89,7 @@ public function testDontShowDeleteButtons()
     public function testShowDeleteButtonsWithAdminPermission()
     {
         $this->logInWithPermission('ADMIN');
-        $content = new CSSContentParser($this->gridField->FieldHolder());
+        $content = new CSSContentParser($this->gridField->renderFieldHolder());
         $deleteButtons = $content->getBySelector('.action--delete');
         $this->assertEquals(3, count($deleteButtons ?? []), 'Delete buttons should show when logged in.');
     }
diff --git a/tests/php/Forms/GridField/GridFieldEditButtonTest.php b/tests/php/Forms/GridField/GridFieldEditButtonTest.php
index c650b7a1995..137cd915655 100644
--- a/tests/php/Forms/GridField/GridFieldEditButtonTest.php
+++ b/tests/php/Forms/GridField/GridFieldEditButtonTest.php
@@ -67,7 +67,7 @@ public function testShowEditLinks()
             Security::setCurrentUser(null);
         }
 
-        $content = new CSSContentParser($this->gridField->FieldHolder());
+        $content = new CSSContentParser($this->gridField->renderFieldHolder());
         // Check that there are content
         $this->assertEquals(4, count($content->getBySelector('.ss-gridfield-item') ?? []));
         // Make sure that there are edit links, even though the user doesn't have "edit" permissions
@@ -82,7 +82,7 @@ public function testShowEditLinks()
     public function testShowEditLinksWithAdminPermission()
     {
         $this->logInWithPermission('ADMIN');
-        $content = new CSSContentParser($this->gridField->FieldHolder());
+        $content = new CSSContentParser($this->gridField->renderFieldHolder());
         $editLinks = $content->getBySelector('.edit-link');
         $this->assertEquals(3, count($editLinks ?? []), 'Edit links should show when logged in.');
     }
diff --git a/tests/php/Forms/GridField/GridFieldPaginatorTest.php b/tests/php/Forms/GridField/GridFieldPaginatorTest.php
index f2febae4b1a..86d0d94213a 100644
--- a/tests/php/Forms/GridField/GridFieldPaginatorTest.php
+++ b/tests/php/Forms/GridField/GridFieldPaginatorTest.php
@@ -64,7 +64,7 @@ protected function setUp(): void
 
     public function testThereIsPaginatorWhenMoreThanOnePage()
     {
-        $fieldHolder = $this->gridField->FieldHolder();
+        $fieldHolder = $this->gridField->renderFieldHolder();
         $content = new CSSContentParser($fieldHolder);
         // Check that there is paginator render into the footer
         $this->assertEquals(1, count($content->getBySelector('.datagrid-pagination') ?? []));
@@ -79,7 +79,7 @@ public function testThereIsNoPaginatorWhenOnlyOnePage()
         // on the fixture YML file
         $total = $this->list->count();
         $this->gridField->getConfig()->getComponentByType(GridFieldPaginator::class)->setItemsPerPage($total);
-        $fieldHolder = $this->gridField->FieldHolder();
+        $fieldHolder = $this->gridField->renderFieldHolder();
         $content = new CSSContentParser($fieldHolder);
 
         // Check that there is no paginator render into the footer
diff --git a/tests/php/Forms/GridField/GridFieldTest.php b/tests/php/Forms/GridField/GridFieldTest.php
index 1eba6d4edf5..30646fa32d2 100644
--- a/tests/php/Forms/GridField/GridFieldTest.php
+++ b/tests/php/Forms/GridField/GridFieldTest.php
@@ -393,7 +393,7 @@ public function testGridFieldCustomFragments()
 
         $this->assertStringContainsString(
             "<div class=\"right\">rightone\nrighttwo</div><div class=\"left\">left</div>",
-            $field->FieldHolder()
+            $field->renderFieldHolder()
         );
     }
 
@@ -429,7 +429,7 @@ public function testGridFieldCustomFragmentsNesting()
 
         $this->assertStringContainsString(
             "<div>first\n<strong>second</strong></div>",
-            $field->FieldHolder()
+            $field->renderFieldHolder()
         );
     }
 
@@ -464,7 +464,7 @@ public function testGridFieldCustomFragmentsCircularDependencyThrowsException()
         $field = new GridField('testfield', 'testfield', ArrayList::create(), $config);
         $form = new Form(null, 'testform', new FieldList([$field]), new FieldList());
 
-        $field->FieldHolder();
+        $field->renderFieldHolder();
     }
 
     public function testCanViewOnlyOddIDs()
@@ -500,7 +500,7 @@ public function testCanViewOnlyOddIDs()
         $config->addComponent(new GridFieldDataColumns());
         $obj = new GridField('testfield', 'testfield', $list, $config);
         $form = new Form(null, 'mockform', new FieldList([$obj]), new FieldList());
-        $content = new CSSContentParser($obj->FieldHolder());
+        $content = new CSSContentParser($obj->renderFieldHolder());
 
         $members = $content->getBySelector('.ss-gridfield-item tr');
 
@@ -555,7 +555,7 @@ public function testValidationMessageInOutput()
 
         // A form that fails validation should display the validation error in the FieldHolder output.
         $form->validationResult();
-        $gridfieldOutput = $gridField->FieldHolder();
+        $gridfieldOutput = $gridField->renderFieldHolder();
         $this->assertStringContainsString('<p class="message ' . ValidationResult::TYPE_ERROR . '">error</p>', $gridfieldOutput);
 
         // Clear validation error from previous assertion.
@@ -565,7 +565,7 @@ public function testValidationMessageInOutput()
         // A form that passes validation should not display a validation error in the FieldHolder output.
         $form->setValidator(new RequiredFields());
         $form->validationResult();
-        $gridfieldOutput = $gridField->FieldHolder();
+        $gridfieldOutput = $gridField->renderFieldHolder();
         $this->assertStringNotContainsString('<p class="message ' . ValidationResult::TYPE_ERROR . '">', $gridfieldOutput);
     }
 
diff --git a/tests/php/Forms/GroupedDropdownFieldTest.php b/tests/php/Forms/GroupedDropdownFieldTest.php
index ccd06f7f50d..3a3cd663eed 100644
--- a/tests/php/Forms/GroupedDropdownFieldTest.php
+++ b/tests/php/Forms/GroupedDropdownFieldTest.php
@@ -84,7 +84,7 @@ public function testEmptyString()
 
         $this->assertMatchesRegularExpression(
             '/<option value="" selected="selected" >\(Choose A\)<\/option>/',
-            preg_replace('/\s+/', ' ', (string)$field->Field())
+            preg_replace('/\s+/', ' ', (string)$field->renderField())
         );
 
         // Case B: empty value in the nested level of the source
@@ -105,7 +105,7 @@ public function testEmptyString()
         );
         $this->assertMatchesRegularExpression(
             '/<option value="" selected="selected" >\(Choose B\)<\/option>/',
-            preg_replace('/\s+/', ' ', (string)$field->Field())
+            preg_replace('/\s+/', ' ', (string)$field->renderField())
         );
 
         // Case C: setEmptyString
@@ -126,7 +126,7 @@ public function testEmptyString()
         $field->setEmptyString('(Choose C)');
         $this->assertMatchesRegularExpression(
             '/<option value="" selected="selected" >\(Choose C\)<\/option>/',
-            preg_replace('/\s+/', ' ', (string)$field->Field())
+            preg_replace('/\s+/', ' ', (string)$field->renderField())
         );
     }
 
@@ -154,14 +154,14 @@ public function testReadonlyValue()
         $field->setValue("1");
         $this->assertMatchesRegularExpression(
             '#<span class="readonly" id="Test">One</span>\n?<input type="hidden" name="Test" value="1" />#',
-            (string)$field->performReadonlyTransformation()->Field()
+            (string)$field->performReadonlyTransformation()->renderField()
         );
 
         // value on first level
         $field->setValue("2");
         $this->assertMatchesRegularExpression(
             '#<span class="readonly" id="Test">Two</span>\n?<input type="hidden" name="Test" value="2" />#',
-            (string)$field->performReadonlyTransformation()->Field()
+            (string)$field->performReadonlyTransformation()->renderField()
         );
     }
 }
diff --git a/tests/php/Forms/HTMLEditor/HTMLEditorFieldTest.php b/tests/php/Forms/HTMLEditor/HTMLEditorFieldTest.php
index d9f69cfe49c..5d1db01ea11 100644
--- a/tests/php/Forms/HTMLEditor/HTMLEditorFieldTest.php
+++ b/tests/php/Forms/HTMLEditor/HTMLEditorFieldTest.php
@@ -76,12 +76,12 @@ public function testCasting()
         $inputText = "These are some unicodes: ä, ö, & ü";
         $field = new HTMLEditorField("Test", "Test");
         $field->setValue($inputText);
-        $this->assertStringContainsString('These are some unicodes: ä, ö, & ü', $field->Field());
+        $this->assertStringContainsString('These are some unicodes: ä, ö, & ü', $field->renderField());
         // Test shortcodes
         $inputText = "Shortcode: [file_link id=4]";
         $field = new HTMLEditorField("Test", "Test");
         $field->setValue($inputText);
-        $this->assertStringContainsString('Shortcode: [file_link id=4]', $field->Field());
+        $this->assertStringContainsString('Shortcode: [file_link id=4]', $field->renderField());
     }
 
     public function testBasicSaving()
@@ -178,7 +178,7 @@ public function testReadonlyField()
         /** @var HTMLReadonlyField $readonly */
         $readonly = $editor->performReadonlyTransformation();
         /** @var DBHTMLText $readonlyContent */
-        $readonlyContent = $readonly->Field();
+        $readonlyContent = $readonly->renderField();
 
         $this->assertEquals(
             <<<EOS
@@ -198,7 +198,7 @@ public function testReadonlyField()
         $readonly = $editor->performReadonlyTransformation()
             ->setIncludeHiddenField(true);
         /** @var DBHTMLText $readonlyContent */
-        $readonlyContent = $readonly->Field();
+        $readonlyContent = $readonly->renderField();
         $this->assertEquals(
             <<<EOS
 <span class="readonly typography" id="Content">
diff --git a/tests/php/Forms/ListboxFieldTest.php b/tests/php/Forms/ListboxFieldTest.php
index 662918cc865..2afc31f6e19 100644
--- a/tests/php/Forms/ListboxFieldTest.php
+++ b/tests/php/Forms/ListboxFieldTest.php
@@ -32,7 +32,7 @@ public function testFieldWithManyManyRelationship()
         $field = new ListboxField("Tags", "Test field", DataObject::get(Tag::class)->map()->toArray());
         $field->setValue(null, $articleWithTags);
 
-        $p = new CSSContentParser($field->Field());
+        $p = new CSSContentParser($field->renderField());
         $tag1xml = $p->getByXpath('//option[@value=' . $tag1->ID . ']');
         $tag2xml = $p->getByXpath('//option[@value=' . $tag2->ID . ']');
         $tag3xml = $p->getByXpath('//option[@value=' . $tag3->ID . ']');
@@ -51,7 +51,7 @@ public function testFieldWithDisabledItems()
         $field->setValue(null, $articleWithTags);
         $field->setDisabledItems([$tag1->ID, $tag3->ID]);
 
-        $p = new CSSContentParser($field->Field());
+        $p = new CSSContentParser($field->renderField());
         $tag1xml = $p->getByXpath('//option[@value=' . $tag1->ID . ']');
         $tag2xml = $p->getByXpath('//option[@value=' . $tag2->ID . ']');
         $tag3xml = $p->getByXpath('//option[@value=' . $tag3->ID . ']');
@@ -152,7 +152,7 @@ public function testFieldRenderingMultipleOff()
         $choices = ['a' => 'a value', 'b' => 'b value','c' => 'c value'];
         $field = new ListboxField('Choices', 'Choices', $choices);
         $field->setValue('a');
-        $parser = new CSSContentParser($field->Field());
+        $parser = new CSSContentParser($field->renderField());
         $optEls = $parser->getBySelector('option');
         $this->assertEquals(3, count($optEls ?? []));
         $this->assertEquals('selected', (string)$optEls[0]['selected']);
@@ -165,7 +165,7 @@ public function testFieldRenderingMultipleOn()
         $choices = ['a' => 'a value', 'b' => 'b value','c' => 'c value'];
         $field = new ListboxField('Choices', 'Choices', $choices);
         $field->setValue(['a', 'c']);
-        $parser = new CSSContentParser($field->Field());
+        $parser = new CSSContentParser($field->renderField());
         $optEls = $parser->getBySelector('option');
         $this->assertEquals(3, count($optEls ?? []));
         $this->assertEquals('selected', (string)$optEls[0]['selected']);
@@ -257,7 +257,7 @@ public function testFieldWithDefaultItems()
         $field->setDisabledItems([$tag1->ID, $tag3->ID]);
 
         // Confirm that tag1 and tag2 are selected
-        $p = new CSSContentParser($field->Field());
+        $p = new CSSContentParser($field->renderField());
         $tag1xml = $p->getByXpath('//option[@value=' . $tag1->ID . ']');
         $tag2xml = $p->getByXpath('//option[@value=' . $tag2->ID . ']');
         $tag3xml = $p->getByXpath('//option[@value=' . $tag3->ID . ']');
@@ -266,7 +266,7 @@ public function testFieldWithDefaultItems()
         $this->assertNull($tag3xml[0]['selected']);
 
         // Confirm that tag1 and tag2 are listed in the readonly variation
-        $p = new CSSContentParser($field->performReadonlyTransformation()->Field());
+        $p = new CSSContentParser($field->performReadonlyTransformation()->renderField());
         $this->assertEquals(
             'Tag 1, Tag 2',
             trim(preg_replace('/\s+/', ' ', $p->getByXpath('//span')[0] ?? '') ?? '')
diff --git a/tests/php/Forms/LookupFieldTest.php b/tests/php/Forms/LookupFieldTest.php
index 2cc72b25be0..c1d2caa016c 100644
--- a/tests/php/Forms/LookupFieldTest.php
+++ b/tests/php/Forms/LookupFieldTest.php
@@ -16,7 +16,7 @@ public function testNullValueWithNumericArraySource()
         $source = [1 => 'one', 2 => 'two', 3 => 'three'];
         $field = new LookupField('test', 'test', $source);
         $field->setValue(null);
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
 
         $this->assertStringContainsString('<span class="readonly" id="test"><i>(none)</i></span>', $result);
         $this->assertStringContainsString('<input type="hidden" name="test" value="" />', $result);
@@ -27,7 +27,7 @@ public function testStringValueWithNumericArraySource()
         $source = [1 => 'one', 2 => 'two', 3 => 'three'];
         $field = new LookupField('test', 'test', $source);
         $field->setValue(1);
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
         $this->assertStringContainsString('<span class="readonly" id="test">one</span>', $result);
         $this->assertStringContainsString('<input type="hidden" name="test" value="1" />', $result);
     }
@@ -37,7 +37,7 @@ public function testUnknownStringValueWithNumericArraySource()
         $source = [1 => 'one', 2 => 'two', 3 => 'three'];
         $field = new LookupField('test', 'test', $source);
         $field->setValue('w00t');
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
 
         $this->assertStringContainsString('<span class="readonly" id="test">w00t</span>', $result);
         $this->assertStringContainsString('<input type="hidden" name="test" value="" />', $result);
@@ -49,7 +49,7 @@ public function testArrayValueWithAssociativeArraySource()
         $source = ['one' => 'one val', 'two' => 'two val', 'three' => 'three val'];
         $field = new LookupField('test', 'test', $source);
         $field->setValue(['one','two']);
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
 
         $this->assertStringContainsString('<span class="readonly" id="test">one val, two val</span>', $result);
         $this->assertStringContainsString('<input type="hidden" name="test" value="one, two" />', $result);
@@ -61,7 +61,7 @@ public function testArrayValueWithNumericArraySource()
         $source = [1 => 'one', 2 => 'two', 3 => 'three'];
         $field = new LookupField('test', 'test', $source);
         $field->setValue([1,2]);
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
 
         $this->assertStringContainsString('<span class="readonly" id="test">one, two</span>', $result);
         $this->assertStringContainsString('<input type="hidden" name="test" value="1, 2" />', $result);
@@ -76,7 +76,7 @@ public function testArrayValueWithSqlMapSource()
         $source = DataObject::get(Member::class);
         $field = new LookupField('test', 'test', $source->map('ID', 'FirstName'));
         $field->setValue([$member1->ID, $member2->ID]);
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
 
         $this->assertStringContainsString('<span class="readonly" id="test">member1, member2</span>', $result);
         $this->assertStringContainsString(sprintf(
@@ -102,13 +102,13 @@ public function testWithMultiDimensionalSource()
 
         $field = new LookupField('test', 'test', $choices);
         $field->setValue(3);
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
 
         $this->assertStringContainsString('<span class="readonly" id="test">Carrots</span>', $result);
         $this->assertStringContainsString('<input type="hidden" name="test" value="3" />', $result);
 
         $field->setValue([3, 9]);
-        $result = trim($field->Field()->getValue() ?? '');
+        $result = trim($field->renderField()->getValue() ?? '');
 
         $this->assertStringContainsString('<span class="readonly" id="test">Carrots, Vegan</span>', $result);
         $this->assertStringContainsString('<input type="hidden" name="test" value="3, 9" />', $result);
diff --git a/tests/php/Forms/NullableFieldTests.php b/tests/php/Forms/NullableFieldTests.php
index 8cb1dd8ef4c..4e0e312aa5b 100644
--- a/tests/php/Forms/NullableFieldTests.php
+++ b/tests/php/Forms/NullableFieldTests.php
@@ -24,7 +24,7 @@ public function testWithContent()
         $this->assertEquals("Field 1", $a->Title());
         $this->assertSame("abc", $a->Value());
         $this->assertSame("abc", $a->dataValue());
-        $field = $a->Field();
+        $field = $a->renderField();
         $this->assertTag(
             [
             'tag'=>'input',
@@ -52,7 +52,7 @@ public function testWithEmpty()
         $this->assertEquals("Field 1", $a->Title());
         $this->assertSame("", $a->Value());
         $this->assertSame("", $a->dataValue());
-        $field = $a->Field();
+        $field = $a->renderField();
         $this->assertTag(
             [
             'tag'=>'input',
@@ -80,7 +80,7 @@ public function testWithNull()
         $this->assertEquals("Field 1", $a->Title());
         $this->assertSame(null, $a->Value());
         $this->assertSame(null, $a->dataValue());
-        $field = $a->Field();
+        $field = $a->renderField();
         $this->assertTag(
             [
             'tag'=>'input',
diff --git a/tests/php/Forms/NumericFieldTest.php b/tests/php/Forms/NumericFieldTest.php
index 2b52db3351d..8b599c23abc 100644
--- a/tests/php/Forms/NumericFieldTest.php
+++ b/tests/php/Forms/NumericFieldTest.php
@@ -98,7 +98,7 @@ public function testReadonly()
         $field->setLocale('de_DE');
         $field->setScale(2);
         $field->setValue(1001.3);
-        $html = $field->performReadonlyTransformation()->Field()->forTemplate();
+        $html = $field->performReadonlyTransformation()->renderField()->forTemplate();
         $this->assertStringContainsString('value="1.001,30"', $html);
         $this->assertStringContainsString('readonly="readonly"', $html);
     }
@@ -107,7 +107,7 @@ public function testNumberTypeOnInputHtml()
     {
         $field = new NumericField('Number');
 
-        $html = $field->Field();
+        $html = $field->renderField();
         $this->assertStringContainsString('type="text"', $html, 'number type not set');
     }
 
diff --git a/tests/php/Forms/OptionsetFieldTest.php b/tests/php/Forms/OptionsetFieldTest.php
index 34142ec2973..72913f3d60e 100644
--- a/tests/php/Forms/OptionsetFieldTest.php
+++ b/tests/php/Forms/OptionsetFieldTest.php
@@ -22,7 +22,7 @@ public function testSetDisabledItems()
         );
 
         $f->setDisabledItems([0]);
-        $p = new CSSContentParser($f->Field());
+        $p = new CSSContentParser($f->renderField());
         $item0 = $p->getBySelector('#Test_0');
         $item1 = $p->getBySelector('#Test_1');
         $this->assertEquals(
@@ -76,7 +76,7 @@ public function testReadonlyField()
         $field->setEmptyString('(Select one)');
         $field->setValue(1);
         $readonlyField = $field->performReadonlyTransformation();
-        preg_match('/Yes/', $readonlyField->Field() ?? '', $matches);
+        preg_match('/Yes/', $readonlyField->renderField() ?? '', $matches);
         $this->assertEquals($matches[0], 'Yes');
     }
 
@@ -91,7 +91,7 @@ public function testSafelyCast()
             3 => DBField::create_field('HTMLText', 'Four &amp; Five &amp; Six')
             ]
         );
-        $fieldHTML = (string)$field1->Field();
+        $fieldHTML = (string)$field1->renderField();
         $this->assertStringContainsString('One', $fieldHTML);
         $this->assertStringContainsString('Two &amp; Three', $fieldHTML);
         $this->assertStringNotContainsString('Two & Three', $fieldHTML);
diff --git a/tests/php/Forms/PrintableTransformationTabSetTest.php b/tests/php/Forms/PrintableTransformationTabSetTest.php
index b821b815ba2..037456062b3 100644
--- a/tests/php/Forms/PrintableTransformationTabSetTest.php
+++ b/tests/php/Forms/PrintableTransformationTabSetTest.php
@@ -23,13 +23,13 @@ public function testFieldHolder()
         ];
 
         $transformationTabSet = new PrintableTransformation_TabSet($tabs);
-        $result = $transformationTabSet->FieldHolder();
+        $result = $transformationTabSet->renderFieldHolder();
 
         $this->assertStringContainsString('<h1>Main</h1>', $result);
         $this->assertStringContainsString('<h1>Secondary</h1>', $result);
 
         $transformationTabSet->setTabSet($optionsTabSet);
-        $result = $transformationTabSet->FieldHolder();
+        $result = $transformationTabSet->renderFieldHolder();
 
         $this->assertStringContainsString('<h2>Options</h2>', $result);
     }
diff --git a/tests/php/Forms/SearchableDropdownTraitTest.php b/tests/php/Forms/SearchableDropdownTraitTest.php
index c20f4f81d81..3b0e5e1327d 100644
--- a/tests/php/Forms/SearchableDropdownTraitTest.php
+++ b/tests/php/Forms/SearchableDropdownTraitTest.php
@@ -221,7 +221,7 @@ public function testGetSchemaDataDefaults(): void
     public static function provideLazyLoadedDoesntCallGetSource()
     {
         $methodsToCall = [
-            'Field',
+            'renderField',
             'getSchemaStateDefaults',
             'getSchemaState',
             'getSchemaDataDefaults',
diff --git a/tests/php/Forms/SelectionGroupTest.php b/tests/php/Forms/SelectionGroupTest.php
index 711695d5ce7..d036b9792e4 100644
--- a/tests/php/Forms/SelectionGroupTest.php
+++ b/tests/php/Forms/SelectionGroupTest.php
@@ -25,7 +25,7 @@ public function testFieldHolder()
             ),
         ];
         $field = new SelectionGroup('MyGroup', $items);
-        $parser = new CSSContentParser($field->FieldHolder());
+        $parser = new CSSContentParser($field->renderFieldHolder());
         $listEls = $parser->getBySelector('li');
         $listElOne = $listEls[0];
         $listElTwo = $listEls[1];
@@ -57,7 +57,7 @@ public function testSelectedFieldHolder()
         $field = new SelectionGroup('MyGroup', $items);
         $field->setValue('two');
 
-        $parser = new CSSContentParser($field->FieldHolder());
+        $parser = new CSSContentParser($field->renderFieldHolder());
 
         $listEls = $parser->getBySelector('li');
         $listElOne = $listEls[0];
@@ -75,7 +75,7 @@ public function testLegacyItemsFieldHolder()
             'two' => new LiteralField('two', 'two view'),
         ];
         $field = new SelectionGroup('MyGroup', $items);
-        $parser = new CSSContentParser($field->FieldHolder());
+        $parser = new CSSContentParser($field->renderFieldHolder());
         $listEls = $parser->getBySelector('li');
         $listElOne = $listEls[0];
         $listElTwo = $listEls[1];
@@ -94,7 +94,7 @@ public function testLegacyItemsFieldHolderWithTitle()
             'two//two title' => new LiteralField('two', 'two view'),
         ];
         $field = new SelectionGroup('MyGroup', $items);
-        $parser = new CSSContentParser($field->FieldHolder());
+        $parser = new CSSContentParser($field->renderFieldHolder());
         $listEls = $parser->getBySelector('li');
         $listElOne = $listEls[0];
         $listElTwo = $listEls[1];
diff --git a/tests/php/Forms/SingleLookupFieldTest.php b/tests/php/Forms/SingleLookupFieldTest.php
index b699dd2d2b8..0cde348755d 100644
--- a/tests/php/Forms/SingleLookupFieldTest.php
+++ b/tests/php/Forms/SingleLookupFieldTest.php
@@ -25,7 +25,7 @@ public function testValueFromSource()
         $this->assertInstanceOf(SingleLookupField::class, $testField);
 
         $testField->setValue('member1');
-        preg_match('/Member 1/', $testField->Field() ?? '', $matches);
+        preg_match('/Member 1/', $testField->renderField() ?? '', $matches);
         $this->assertEquals($matches[0], 'Member 1');
     }
 
@@ -41,7 +41,7 @@ public function testValueNotFromSource()
         $this->assertInstanceOf(SingleLookupField::class, $testField);
 
         $testField->setValue('member123');
-        preg_match('/\(none\)/', $testField->Field() ?? '', $matches);
+        preg_match('/\(none\)/', $testField->renderField() ?? '', $matches);
         $this->assertEquals($matches[0], '(none)');
     }
 }
diff --git a/tests/php/Forms/TextareaFieldTest.php b/tests/php/Forms/TextareaFieldTest.php
index f75bd4589ad..b661c2dcffa 100644
--- a/tests/php/Forms/TextareaFieldTest.php
+++ b/tests/php/Forms/TextareaFieldTest.php
@@ -15,12 +15,12 @@ public function testCasting()
         $inputText = "These are some unicodes: ä, ö, & ü";
         $field = new TextareaField("Test", "Test");
         $field->setValue($inputText);
-        $this->assertStringContainsString('These are some unicodes: &auml;, &ouml;, &amp; &uuml;', $field->Field());
+        $this->assertStringContainsString('These are some unicodes: &auml;, &ouml;, &amp; &uuml;', $field->renderField());
         // Test shortcodes
         $inputText = "Shortcode: [file_link id=4]";
         $field = new TextareaField("Test", "Test");
         $field->setValue($inputText);
-        $this->assertStringContainsString('Shortcode: [file_link id=4]', $field->Field());
+        $this->assertStringContainsString('Shortcode: [file_link id=4]', $field->renderField());
     }
 
     /**
@@ -32,7 +32,7 @@ public function testReadonlyDisplayUnicodes()
         $field = new TextareaField("Test", "Test");
         $field->setValue($inputText);
         $field = $field->performReadonlyTransformation();
-        $this->assertStringContainsString('These are some unicodes: äöü', $field->Field());
+        $this->assertStringContainsString('These are some unicodes: äöü', $field->renderField());
     }
 
     /**
@@ -47,7 +47,7 @@ public function testReadonlyDisplaySpecialHTML()
         $this->assertStringContainsString(
             'These are some special &lt;html&gt; chars including &#039;single&#039; &amp;'
             . ' &quot;double&quot; quotations',
-            $field->Field()
+            $field->renderField()
         );
     }
 
diff --git a/tests/php/Forms/TreeDropdownFieldTest.php b/tests/php/Forms/TreeDropdownFieldTest.php
index 83e091f89e6..1c9384f1c66 100644
--- a/tests/php/Forms/TreeDropdownFieldTest.php
+++ b/tests/php/Forms/TreeDropdownFieldTest.php
@@ -314,7 +314,7 @@ public function testTreeSearchUsingSubObject()
         $noResult = $parser->getBySelector($cssPath);
         $this->assertEmpty(
             $noResult,
-            $subObject2 . ' is not found'
+            get_class($subObject2) . ' is not found'
         );
     }
 
@@ -324,7 +324,7 @@ public function testReadonly()
         $fileMock = $this->objFromFixture(File::class, 'asdf');
         $field->setValue($fileMock->ID);
         $readonlyField = $field->performReadonlyTransformation();
-        $result = (string) $readonlyField->Field();
+        $result = (string) $readonlyField->renderField();
         $this->assertStringContainsString(
             '<span class="readonly" id="TestTree">&lt;Special &amp; characters&gt;</span>',
             $result
diff --git a/tests/php/Forms/TreeMultiselectFieldTest.php b/tests/php/Forms/TreeMultiselectFieldTest.php
index 408ab4af861..04b11356665 100644
--- a/tests/php/Forms/TreeMultiselectFieldTest.php
+++ b/tests/php/Forms/TreeMultiselectFieldTest.php
@@ -155,7 +155,7 @@ public function testEmpty()
         $items = $field->getItems();
         $this->assertCount(0, $items, 'there must be no items selected');
 
-        $html = $field->Field();
+        $html = $field->renderField();
         $this->assertStringContainsString($field->ID(), $html);
         $this->assertStringContainsString('unchanged', $html);
     }
@@ -178,7 +178,7 @@ public function testChanged()
         $items = $field->getItems();
         $this->assertCount(2, $items, 'there must be exactly 2 items selected');
 
-        $html = $field->Field();
+        $html = $field->renderField();
         $this->assertStringContainsString($field->ID(), $html);
         $this->assertStringContainsString($this->fieldValue, $html);
     }
@@ -213,7 +213,7 @@ public function testEmptyReadonly()
         $items = $field->getItems();
         $this->assertCount(0, $items, 'there must be 0 selected items');
 
-        $html = $field->Field();
+        $html = $field->renderField();
         $this->assertStringContainsString($field->ID(), $html);
     }
 
@@ -249,7 +249,7 @@ public function testChangedReadonly()
         $items = $field->getItems();
         $this->assertCount(2, $items, 'there must be exactly 2 selected items');
 
-        $html = $field->Field();
+        $html = $field->renderField();
         $this->assertStringContainsString($field->ID(), $html);
         $this->assertStringContainsString($this->fieldValue, $html);
     }
diff --git a/tests/php/Model/ModelDataTest.php b/tests/php/Model/ModelDataTest.php
index 33f4b171d3a..f3e910b774d 100644
--- a/tests/php/Model/ModelDataTest.php
+++ b/tests/php/Model/ModelDataTest.php
@@ -122,7 +122,7 @@ public function testObjectCustomise()
         $this->assertEquals('casted', $newModelData->XML_val('alwaysCasted'));
 
         $this->assertEquals('castable', $modelData->forTemplate());
-        $this->assertEquals('casted', $newModelData->forTemplate());
+        $this->assertEquals('castable', $newModelData->forTemplate());
     }
 
     public function testDefaultValueWrapping()
@@ -139,25 +139,6 @@ public function testDefaultValueWrapping()
         $this->assertEquals('SomeTitleValue', $obj->forTemplate());
     }
 
-    public function testCastingClass()
-    {
-        $expected = [
-            //'NonExistant'   => null,
-            'Field'         => 'CastingType',
-            'Argument'      => 'ArgumentType',
-            'ArrayArgument' => 'ArrayArgumentType'
-        ];
-        $obj = new ModelDataTest\CastingClass();
-
-        foreach ($expected as $field => $class) {
-            $this->assertEquals(
-                $class,
-                $obj->castingClass($field),
-                "castingClass() returns correct results for ::\$$field"
-            );
-        }
-    }
-
     public function testObjWithCachedStringValueReturnsValidObject()
     {
         $obj = new ModelDataTest\NoCastingInformation();
diff --git a/tests/php/Model/ModelDataTest/NotCached.php b/tests/php/Model/ModelDataTest/NotCached.php
index 2b988824932..57678e6411e 100644
--- a/tests/php/Model/ModelDataTest/NotCached.php
+++ b/tests/php/Model/ModelDataTest/NotCached.php
@@ -9,7 +9,7 @@ class NotCached extends ModelData implements TestOnly
 {
     public $Test;
 
-    protected function objCacheGet($key)
+    public function objCacheGet(string $fieldName, array $arguments = []): mixed
     {
         // Disable caching
         return null;
diff --git a/tests/php/ORM/Filters/EndsWithFilterTest.php b/tests/php/ORM/Filters/EndsWithFilterTest.php
index 40c69c0e209..907715d0767 100644
--- a/tests/php/ORM/Filters/EndsWithFilterTest.php
+++ b/tests/php/ORM/Filters/EndsWithFilterTest.php
@@ -197,20 +197,6 @@ public static function provideMatches()
                 'modifiers' => [],
                 'matches' => false,
             ],
-            // These will both evaluate to true because the __toString() method just returns the class name.
-            // We're testing this scenario because ArrayList might contain arbitrary values
-            [
-                'filterValue' => new ArrayData(['SomeField' => 'some value']),
-                'matchValue' => new ArrayData(['SomeField' => 'some value']),
-                'modifiers' => [],
-                'matches' => true,
-            ],
-            [
-                'filterValue' => new ArrayData(['SomeField' => 'SoMe VaLuE']),
-                'matchValue' => new ArrayData(['SomeField' => 'some value']),
-                'modifiers' => [],
-                'matches' => true,
-            ],
             // case insensitive
             [
                 'filterValue' => 'somevalue',
diff --git a/tests/php/ORM/Filters/PartialMatchFilterTest.php b/tests/php/ORM/Filters/PartialMatchFilterTest.php
index 7d11ebe7c10..8a3d5fdaf9e 100644
--- a/tests/php/ORM/Filters/PartialMatchFilterTest.php
+++ b/tests/php/ORM/Filters/PartialMatchFilterTest.php
@@ -197,20 +197,6 @@ public static function provideMatches()
                 'modifiers' => [],
                 'matches' => false,
             ],
-            // These will both evaluate to true because the __toString() method just returns the class name.
-            // We're testing this scenario because ArrayList might contain arbitrary values
-            [
-                'filterValue' => new ArrayData(['SomeField' => 'some value']),
-                'matchValue' => new ArrayData(['SomeField' => 'some value']),
-                'modifiers' => [],
-                'matches' => true,
-            ],
-            [
-                'filterValue' => new ArrayData(['SomeField' => 'SoMe VaLuE']),
-                'matchValue' => new ArrayData(['SomeField' => 'some value']),
-                'modifiers' => [],
-                'matches' => true,
-            ],
             // case insensitive
             [
                 'filterValue' => 'somevalue',
diff --git a/tests/php/ORM/Filters/StartsWithFilterTest.php b/tests/php/ORM/Filters/StartsWithFilterTest.php
index 32e2050ff83..66a2d8b16bd 100644
--- a/tests/php/ORM/Filters/StartsWithFilterTest.php
+++ b/tests/php/ORM/Filters/StartsWithFilterTest.php
@@ -197,20 +197,6 @@ public static function provideMatches()
                 'modifiers' => [],
                 'matches' => false,
             ],
-            // These will both evaluate to true because the __toString() method just returns the class name.
-            // We're testing this scenario because ArrayList might contain arbitrary values
-            [
-                'filterValue' => new ArrayData(['SomeField' => 'some value']),
-                'matchValue' => new ArrayData(['SomeField' => 'some value']),
-                'modifiers' => [],
-                'matches' => true,
-            ],
-            [
-                'filterValue' => new ArrayData(['SomeField' => 'SoMe VaLuE']),
-                'matchValue' => new ArrayData(['SomeField' => 'some value']),
-                'modifiers' => [],
-                'matches' => true,
-            ],
             // case insensitive
             [
                 'filterValue' => 'somevalue',
diff --git a/tests/php/ORM/LabelFieldTest.php b/tests/php/ORM/LabelFieldTest.php
index 58f3b4edaf1..def2c3fb781 100644
--- a/tests/php/ORM/LabelFieldTest.php
+++ b/tests/php/ORM/LabelFieldTest.php
@@ -11,6 +11,6 @@ class LabelFieldTest extends SapphireTest
     public function testFieldHasNoNameAttribute()
     {
         $field = new LabelField('MyName', 'MyTitle');
-        $this->assertEquals(trim($field->Field() ?? ''), '<label id="MyName" class="readonly">MyTitle</label>');
+        $this->assertEquals(trim($field->renderField() ?? ''), '<label id="MyName" class="readonly">MyTitle</label>');
     }
 }
diff --git a/tests/php/Security/PermissionCheckboxSetFieldTest.php b/tests/php/Security/PermissionCheckboxSetFieldTest.php
index 5aa3f4830d7..0276ad17ba0 100644
--- a/tests/php/Security/PermissionCheckboxSetFieldTest.php
+++ b/tests/php/Security/PermissionCheckboxSetFieldTest.php
@@ -27,8 +27,8 @@ public function testHiddenPermissions()
             $f->getHiddenPermissions(),
             ['NON-ADMIN']
         );
-        $this->assertStringContainsString('ADMIN', $f->Field());
-        $this->assertStringNotContainsString('NON-ADMIN', $f->Field());
+        $this->assertStringContainsString('ADMIN', $f->renderField());
+        $this->assertStringNotContainsString('NON-ADMIN', $f->renderField());
     }
 
     public function testSaveInto()
diff --git a/tests/php/Security/PermissionTest.php b/tests/php/Security/PermissionTest.php
index 6be7a44d201..909cb7e01eb 100644
--- a/tests/php/Security/PermissionTest.php
+++ b/tests/php/Security/PermissionTest.php
@@ -141,14 +141,14 @@ public function testGettingMembersByPermission()
     public function testHiddenPermissions()
     {
         $permissionCheckboxSet = new PermissionCheckboxSetField('Permissions', 'Permissions', Permission::class, 'GroupID');
-        $this->assertStringContainsString('CMS_ACCESS_LeftAndMain', $permissionCheckboxSet->Field());
+        $this->assertStringContainsString('CMS_ACCESS_LeftAndMain', $permissionCheckboxSet->renderField());
 
         Config::modify()->merge(Permission::class, 'hidden_permissions', ['CMS_ACCESS_LeftAndMain']);
 
-        $this->assertStringNotContainsString('CMS_ACCESS_LeftAndMain', $permissionCheckboxSet->Field());
+        $this->assertStringNotContainsString('CMS_ACCESS_LeftAndMain', $permissionCheckboxSet->renderField());
 
         Config::inst()->remove(Permission::class, 'hidden_permissions');
-        $this->assertStringContainsString('CMS_ACCESS_LeftAndMain', $permissionCheckboxSet->Field());
+        $this->assertStringContainsString('CMS_ACCESS_LeftAndMain', $permissionCheckboxSet->renderField());
     }
 
     public function testEmptyMemberFails()
diff --git a/tests/php/View/SSViewerTest.php b/tests/php/View/SSViewerTest.php
index d9de2385f30..881010f5ac3 100644
--- a/tests/php/View/SSViewerTest.php
+++ b/tests/php/View/SSViewerTest.php
@@ -360,8 +360,9 @@ public function testGlobalVariablesAreEscaped()
             'z<div></div>z',
             $this->render('$SSViewerTest_GlobalThatTakesArguments($SSViewerTest_GlobalHTMLFragment)')
         );
+        // Don't escape value when passing into a method call
         $this->assertEquals(
-            'z&lt;div&gt;&lt;/div&gt;z',
+            'z<div></div>z',
             $this->render('$SSViewerTest_GlobalThatTakesArguments($SSViewerTest_GlobalHTMLEscaped)')
         );
     }
@@ -1118,57 +1119,59 @@ public function testBaseTagGeneration()
     public function testIncludeWithArguments()
     {
         $this->assertEquals(
-            $this->render('<% include SSViewerTestIncludeWithArguments %>'),
-            '<p>[out:Arg1]</p><p>[out:Arg2]</p><p>[out:Arg2.Count]</p>'
+            '<p>[out:Arg1]</p><p>[out:Arg2]</p><p>[out:Arg2.Count]</p>',
+            $this->render('<% include SSViewerTestIncludeWithArguments %>')
         );
 
         $this->assertEquals(
-            $this->render('<% include SSViewerTestIncludeWithArguments Arg1=A %>'),
-            '<p>A</p><p>[out:Arg2]</p><p>[out:Arg2.Count]</p>'
+            '<p>A</p><p>[out:Arg2]</p><p>[out:Arg2.Count]</p>',
+            $this->render('<% include SSViewerTestIncludeWithArguments Arg1=A %>')
         );
 
         $this->assertEquals(
-            $this->render('<% include SSViewerTestIncludeWithArguments Arg1=A, Arg2=B %>'),
-            '<p>A</p><p>B</p><p></p>'
+            '<p>A</p><p>B</p><p></p>',
+            $this->render('<% include SSViewerTestIncludeWithArguments Arg1=A, Arg2=B %>')
         );
 
         $this->assertEquals(
-            $this->render('<% include SSViewerTestIncludeWithArguments Arg1=A Bare String, Arg2=B Bare String %>'),
-            '<p>A Bare String</p><p>B Bare String</p><p></p>'
+            '<p>A Bare String</p><p>B Bare String</p><p></p>',
+            $this->render('<% include SSViewerTestIncludeWithArguments Arg1=A Bare String, Arg2=B Bare String %>')
         );
 
         $this->assertEquals(
+            '<p>A</p><p>Bar</p><p></p>',
             $this->render(
                 '<% include SSViewerTestIncludeWithArguments Arg1="A", Arg2=$B %>',
                 new ArrayData(['B' => 'Bar'])
-            ),
-            '<p>A</p><p>Bar</p><p></p>'
+            )
         );
 
         $this->assertEquals(
+            '<p>A</p><p>Bar</p><p></p>',
             $this->render(
                 '<% include SSViewerTestIncludeWithArguments Arg1="A" %>',
                 new ArrayData(['Arg1' => 'Foo', 'Arg2' => 'Bar'])
-            ),
-            '<p>A</p><p>Bar</p><p></p>'
+            )
         );
 
         $this->assertEquals(
-            $this->render('<% include SSViewerTestIncludeWithArguments Arg1="A", Arg2=0 %>'),
-            '<p>A</p><p>0</p><p></p>'
+            '<p>A</p><p>0</p><p></p>',
+            $this->render('<% include SSViewerTestIncludeWithArguments Arg1="A", Arg2=0 %>')
         );
 
         $this->assertEquals(
-            $this->render('<% include SSViewerTestIncludeWithArguments Arg1="A", Arg2=false %>'),
-            '<p>A</p><p></p><p></p>'
+            '<p>A</p><p></p><p></p>',
+            $this->render('<% include SSViewerTestIncludeWithArguments Arg1="A", Arg2=false %>')
         );
 
         $this->assertEquals(
-            $this->render('<% include SSViewerTestIncludeWithArguments Arg1="A", Arg2=null %>'),
-            '<p>A</p><p></p><p></p>'
+            '<p>A</p><p></p><p></p>',
+            // Note Arg2 is explicitly overridden with null
+            $this->render('<% include SSViewerTestIncludeWithArguments Arg1="A", Arg2=null %>')
         );
 
         $this->assertEquals(
+            'SomeArg - Foo - Bar - SomeArg',
             $this->render(
                 '<% include SSViewerTestIncludeScopeInheritanceWithArgsInLoop Title="SomeArg" %>',
                 new ArrayData(
@@ -1179,19 +1182,19 @@ public function testIncludeWithArguments()
                         ]
                     )]
                 )
-            ),
-            'SomeArg - Foo - Bar - SomeArg'
+            )
         );
 
         $this->assertEquals(
+            'A - B - A',
             $this->render(
                 '<% include SSViewerTestIncludeScopeInheritanceWithArgsInWith Title="A" %>',
                 new ArrayData(['Item' => new ArrayData(['Title' =>'B'])])
-            ),
-            'A - B - A'
+            )
         );
 
         $this->assertEquals(
+            'A - B - C - B - A',
             $this->render(
                 '<% include SSViewerTestIncludeScopeInheritanceWithArgsInNestedWith Title="A" %>',
                 new ArrayData(
@@ -1202,11 +1205,11 @@ public function testIncludeWithArguments()
                         ]
                     )]
                 )
-            ),
-            'A - B - C - B - A'
+            )
         );
 
         $this->assertEquals(
+            'A - A - A',
             $this->render(
                 '<% include SSViewerTestIncludeScopeInheritanceWithUpAndTop Title="A" %>',
                 new ArrayData(
@@ -1217,8 +1220,7 @@ public function testIncludeWithArguments()
                         ]
                     )]
                 )
-            ),
-            'A - A - A'
+            )
         );
 
         $data = new ArrayData(
@@ -2202,7 +2204,66 @@ public function testRequireCallInTemplateInclude()
         }
     }
 
-    public function testCallsWithArguments()
+    public static function provideCallsWithArguments(): array
+    {
+        return [
+            [
+                'template' => '$Level.output(1)',
+                'expected' => '1-1',
+            ],
+            [
+                'template' => '$Nest.Level.output($Set.First.Number)',
+                'expected' => '2-1',
+            ],
+            [
+                'template' => '<% with $Set %>$Up.Level.output($First.Number)<% end_with %>',
+                'expected' => '1-1',
+            ],
+            [
+                'template' => '<% with $Set %>$Top.Nest.Level.output($First.Number)<% end_with %>',
+                'expected' => '2-1',
+            ],
+            [
+                'template' => '<% loop $Set %>$Up.Nest.Level.output($Number)<% end_loop %>',
+                'expected' => '2-12-22-32-42-5',
+            ],
+            [
+                'template' => '<% loop $Set %>$Top.Level.output($Number)<% end_loop %>',
+                'expected' => '1-11-21-31-41-5',
+            ],
+            [
+                'template' => '<% with $Nest %>$Level.output($Top.Set.First.Number)<% end_with %>',
+                'expected' => '2-1',
+            ],
+            [
+                'template' => '<% with $Level %>$output($Up.Set.Last.Number)<% end_with %>',
+                'expected' => '1-5',
+            ],
+            [
+                'template' => '<% with $Level.forWith($Set.Last.Number) %>$output("hi")<% end_with %>',
+                'expected' => '5-hi',
+            ],
+            [
+                'template' => '<% loop $Level.forLoop($Set.First.Number) %>$Number<% end_loop %>',
+                'expected' => '!0',
+            ],
+            [
+                'template' => '<% with $Nest %>
+                        <% with $Level.forWith($Up.Set.First.Number) %>$output("hi")<% end_with %>
+                    <% end_with %>',
+                'expected' => '1-hi',
+            ],
+            [
+                'template' => '<% with $Nest %>
+                        <% loop $Level.forLoop($Top.Set.Last.Number) %>$Number<% end_loop %>
+                    <% end_with %>',
+                'expected' => '!0!1!2!3!4',
+            ],
+        ];
+    }
+
+    #[DataProvider('provideCallsWithArguments')]
+    public function testCallsWithArguments(string $template, string $expected): void
     {
         $data = new ArrayData(
             [
@@ -2222,28 +2283,7 @@ public function testCallsWithArguments()
             ]
         );
 
-        $tests = [
-        '$Level.output(1)' => '1-1',
-        '$Nest.Level.output($Set.First.Number)' => '2-1',
-        '<% with $Set %>$Up.Level.output($First.Number)<% end_with %>' => '1-1',
-        '<% with $Set %>$Top.Nest.Level.output($First.Number)<% end_with %>' => '2-1',
-        '<% loop $Set %>$Up.Nest.Level.output($Number)<% end_loop %>' => '2-12-22-32-42-5',
-        '<% loop $Set %>$Top.Level.output($Number)<% end_loop %>' => '1-11-21-31-41-5',
-        '<% with $Nest %>$Level.output($Top.Set.First.Number)<% end_with %>' => '2-1',
-        '<% with $Level %>$output($Up.Set.Last.Number)<% end_with %>' => '1-5',
-        '<% with $Level.forWith($Set.Last.Number) %>$output("hi")<% end_with %>' => '5-hi',
-        '<% loop $Level.forLoop($Set.First.Number) %>$Number<% end_loop %>' => '!0',
-        '<% with $Nest %>
-				<% with $Level.forWith($Up.Set.First.Number) %>$output("hi")<% end_with %>
-			<% end_with %>' => '1-hi',
-        '<% with $Nest %>
-				<% loop $Level.forLoop($Top.Set.Last.Number) %>$Number<% end_loop %>
-			<% end_with %>' => '!0!1!2!3!4',
-        ];
-
-        foreach ($tests as $template => $expected) {
-            $this->assertEquals($expected, trim($this->render($template, $data) ?? ''));
-        }
+        $this->assertEquals($expected, trim($this->render($template, $data) ?? ''));
     }
 
     public function testRepeatedCallsAreCached()
@@ -2360,7 +2400,7 @@ public function testPrimitivesConvertedToDBFields()
     public function testMe(): void
     {
         $myArrayData = new class extends ArrayData {
-            public function forTemplate()
+            public function forTemplate(): string
             {
                 return '';
             }
diff --git a/tests/php/View/SSViewerTest/TestFixture.php b/tests/php/View/SSViewerTest/TestFixture.php
index f0abb39bc69..bdb97fe3b1d 100644
--- a/tests/php/View/SSViewerTest/TestFixture.php
+++ b/tests/php/View/SSViewerTest/TestFixture.php
@@ -2,71 +2,84 @@
 
 namespace SilverStripe\View\Tests\SSViewerTest;
 
-use SilverStripe\Model\List\ArrayList;
-use SilverStripe\Model\ModelData;
+use ReflectionClass;
+use SilverStripe\Dev\TestOnly;
+use SilverStripe\View\SSViewer_Scope;
+use Stringable;
 
 /**
  * A test fixture that will echo back the template item
  */
-class TestFixture extends ModelData
+class TestFixture implements TestOnly, Stringable
 {
-    protected $name;
+    private ?string $name;
 
     public function __construct($name = null)
     {
         $this->name = $name;
-        parent::__construct();
     }
 
-    private function argedName($fieldName, $arguments)
+    public function __call(string $name, array $arguments = []): static|array|null
     {
-        $childName = $this->name ? "$this->name.$fieldName" : $fieldName;
-        if ($arguments) {
-            return $childName . '(' . implode(',', $arguments) . ')';
-        } else {
-            return $childName;
+        return $this->getValue($name, $arguments);
+    }
+
+    public function __get(string $name): static|array|null
+    {
+        return $this->getValue($name);
+    }
+
+    public function __isset(string $name): bool
+    {
+        if (preg_match('/NotSet/i', $name)) {
+            return false;
         }
+        $reflectionScope = new ReflectionClass(SSViewer_Scope::class);
+        $globalProperties = $reflectionScope->getStaticPropertyValue('globalProperties');
+        if (array_key_exists($name, $globalProperties)) {
+            return false;
+        }
+        return true;
     }
 
-    public function obj(
-        string $fieldName,
-        array $arguments = [],
-        bool $cache = false,
-        ?string $cacheName = null
-    ): ?object {
-        $childName = $this->argedName($fieldName, $arguments);
+    public function __toString(): string
+    {
+        if (preg_match('/NotSet/i', $this->name ?? '')) {
+            return '';
+        }
+        if (preg_match('/Raw/i', $this->name ?? '')) {
+            return $this->name ?? '';
+        }
+        return '[out:' . $this->name . ']';
+    }
+
+    private function getValue(string $name, array $arguments = []): static|array|null
+    {
+        $childName = $this->argedName($name, $arguments);
 
         // Special field name Loop### to create a list
-        if (preg_match('/^Loop([0-9]+)$/', $fieldName ?? '', $matches)) {
-            $output = new ArrayList();
+        if (preg_match('/^Loop([0-9]+)$/', $name ?? '', $matches)) {
+            $output = [];
             for ($i = 0; $i < $matches[1]; $i++) {
-                $output->push(new TestFixture($childName));
+                $output[] = new TestFixture($childName);
             }
             return $output;
-        } else {
-            if (preg_match('/NotSet/i', $fieldName ?? '')) {
-                return new ModelData();
-            } else {
-                return new TestFixture($childName);
-            }
         }
-    }
 
-    public function XML_val(string $fieldName, array $arguments = [], bool $cache = false): string
-    {
-        if (preg_match('/NotSet/i', $fieldName ?? '')) {
-            return '';
-        } else {
-            if (preg_match('/Raw/i', $fieldName ?? '')) {
-                return $fieldName;
-            } else {
-                return '[out:' . $this->argedName($fieldName, $arguments) . ']';
-            }
+        if (preg_match('/NotSet/i', $name)) {
+            return null;
         }
+
+        return new TestFixture($childName);
     }
 
-    public function hasValue(string $fieldName, array $arguments = [], bool $cache = true): bool
+    private function argedName(string $fieldName, array $arguments): string
     {
-        return (bool)$this->XML_val($fieldName, $arguments);
+        $childName = $this->name ? "$this->name.$fieldName" : $fieldName;
+        if ($arguments) {
+            return $childName . '(' . implode(',', $arguments) . ')';
+        } else {
+            return $childName;
+        }
     }
 }
diff --git a/tests/php/i18n/i18nTestManifest.php b/tests/php/i18n/i18nTestManifest.php
index d2fd62a133f..2a8bcfb9ec8 100644
--- a/tests/php/i18n/i18nTestManifest.php
+++ b/tests/php/i18n/i18nTestManifest.php
@@ -17,10 +17,10 @@
 use SilverStripe\i18n\Tests\i18nTest\MySubObject;
 use SilverStripe\i18n\Tests\i18nTest\TestDataObject;
 use SilverStripe\View\SSViewer;
-use SilverStripe\View\SSViewer_DataPresenter;
 use SilverStripe\View\ThemeResourceLoader;
 use SilverStripe\View\ThemeManifest;
 use SilverStripe\Model\ModelData;
+use SilverStripe\View\SSViewer_Scope;
 use Symfony\Component\Translation\Loader\ArrayLoader;
 use Symfony\Component\Translation\Translator;
 
@@ -71,9 +71,9 @@ public static function getExtraDataObjects()
 
     public function setupManifest()
     {
-        // force SSViewer_DataPresenter to cache global template vars before we switch to the
+        // force SSViewer_Scope to cache global template vars before we switch to the
         // test-project class manifest (since it will lose visibility of core classes)
-        $presenter = new SSViewer_DataPresenter(new ModelData());
+        $presenter = new SSViewer_Scope(new ModelData());
         unset($presenter);
 
         // Switch to test manifest