add upgrade exception

docs/grid.md

@@ -152,7 +152,7 @@ to populate a content:
 ```
 $grid->addModalAction('Details', 'Additional Details', function (View $p, $id) use ($grid) {
     // $id of the record which was clicked
-    // $grid->model = $grid->model->load($id);
+    // $model = $grid->model->load($id);
 
     LoremIpsum::addTo($p);
 });

src/Form/AbstractLayout.php

@@ -40,7 +40,7 @@ protected function _addControl(Control $control, Field $field): Control
     public function addControl(string $name, $control = [], array $fieldSeed = []): Control
     {
         if ($this->form->entity === null) {
-            $this->form->entity = (new ProxyModel())->createEntity();
+            $this->form->setModel((new ProxyModel())->createEntity());
         }
         $model = $this->form->entity->getModel();
 

src/Table.php

@@ -146,7 +146,7 @@ public function addColumn(?string $name, $columnDecorator = [], $field = [])
         }
 
         if ($this->model === null) {
-            $this->model = new ProxyModel();
+            $this->setModel(new ProxyModel());
         }
         $this->model->assertIsModel();
 

src/View.php

@@ -104,6 +104,17 @@ public function __construct($label = [])
         $this->setDefaults($defaults);
     }
 
+    #[\Override]
+    public function &__get(string $name)
+    {
+        // TODO remove in atk4/ui 6.0
+        if ($name === 'model' && !(new \ReflectionProperty(self::class, 'model'))->isInitialized($this) && $this->entity !== null) {
+            throw new Exception('Use View::$entity property instead for entity access');
+        }
+
+        return parent::__get($name);
+    }
+
     /**
      * Associate this view with a model. Do not place any logic in this class, instead take it
      * to renderView().
@@ -113,8 +124,8 @@ public function __construct($label = [])
      */
     public function setModel(Model $model): void
     {
-        if ($this->model !== null) {
-            if ($this->model === $model) {
+        if (((new \ReflectionProperty(self::class, 'model'))->isInitialized($this) ? $this->model : $this->entity) !== null) {
+            if (((new \ReflectionProperty(self::class, 'model'))->isInitialized($this) ? $this->model : $this->entity) === $model) {
                 return;
             }
 

tests/ViewTest.php

@@ -10,6 +10,7 @@
 use Atk4\Ui\Callback;
 use Atk4\Ui\Console;
 use Atk4\Ui\Exception;
+use Atk4\Ui\Form;
 use Atk4\Ui\JsCallback;
 use Atk4\Ui\JsSse;
 use Atk4\Ui\Loader;
@@ -103,6 +104,22 @@ public function testSetModelTwiceException(): void
         $v->setModel($m2);
     }
 
+    public function testSetModelEntity(): void
+    {
+        $form = new Form();
+        $form->setApp($this->createApp());
+        $form->invokeInit();
+        $entity = (new Model())->createEntity();
+        $form->setModel($entity);
+
+        self::assertSame($entity, $form->entity);
+        self::assertFalse((new \ReflectionProperty(Form::class, 'model'))->isInitialized($form));
+
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Use View::$entity property instead for entity access');
+        $form->model; // @phpstan-ignore-line
+    }
+
     public function testSetSourceZeroKeyException(): void
     {
         $v = new View();