Added XML Field (De)Serialization

* Call parent method in FieldDropdown's fromXml
* Added protected helper methods to handle serialization/deserialization of enabled property/attribute of fields
* Minor changes to annotations to account for field disabling and 4 spaces per line break per style guide

core/field.js

@@ -399,14 +399,39 @@ Blockly.Field.prototype.bindEvents_ = function() {
 };
 
 /**
- * Sets the field's value based on the given XML element. Should only be
- * called by Blockly.Xml.
+ * Disables field if the given XML element specifies this.
  * @param {!Element} fieldElement The element containing info about the
- *    field's state.
+ *     field's state.
+ * @protected
+ */
+Blockly.Field.prototype.setEnabledFromXml_ = function(fieldElement) {
+  if (fieldElement.getAttribute('enabled') === 'false') {
+    this.setEnabled(false);
+  }
+};
+
+/**
+ * Sets the field's value and possibly disables field based on the given XML
+ *     element. Should only be called by Blockly.Xml.
+ * @param {!Element} fieldElement The element containing info about the
+ *     field's state.
  * @package
  */
 Blockly.Field.prototype.fromXml = function(fieldElement) {
   this.setValue(fieldElement.textContent);
+  this.setEnabledFromXml_(fieldElement);
+};
+
+/**
+ * Adds false enabled attribute to the given XML element if field is disabled.
+ * @param {!Element} fieldElement The element containing info about the
+ *     field's state.
+ * @protected
+ */
+Blockly.Field.prototype.addDisabledToXml_ = function(fieldElement) {
+  if (!this.enabled_) {
+    fieldElement.setAttribute('enabled', 'false');
+  }
 };
 
 /**
@@ -418,6 +443,7 @@ Blockly.Field.prototype.fromXml = function(fieldElement) {
  */
 Blockly.Field.prototype.toXml = function(fieldElement) {
   fieldElement.textContent = this.getValue();
+  this.addDisabledToXml_(fieldElement);
   return fieldElement;
 };
 
@@ -460,7 +486,7 @@ Blockly.Field.prototype.updateEditable = function() {
 
 /**
  * Set whether this field's value can be changed using the editor when the
- * source block is editable.
+ *     source block is editable.
  * @param {boolean} enabled True if enabled.
  */
 Blockly.Field.prototype.setEnabled = function(enabled) {
@@ -470,7 +496,7 @@ Blockly.Field.prototype.setEnabled = function(enabled) {
 
 /**
  * Check whether this field's value can be changed using the editor when the
- * source block is editable.
+ *     source block is editable.
  * @return {boolean} Whether this field is enabled.
  */
 Blockly.Field.prototype.isEnabled = function() {

core/field_dropdown.js

@@ -153,17 +153,17 @@ Blockly.FieldDropdown.fromJson = function(options) {
 };
 
 /**
- * Sets the field's value based on the given XML element. Should only be
- * called by Blockly.Xml.
+ * Sets the field's value and possibly disables field based on the given XML
+ *     element. Should only be called by Blockly.Xml.
  * @param {!Element} fieldElement The element containing info about the
- *    field's state.
+ *     field's state.
  * @package
  */
 Blockly.FieldDropdown.prototype.fromXml = function(fieldElement) {
   if (this.isOptionListDynamic()) {
     this.getOptions(false);
   }
-  this.setValue(fieldElement.textContent);
+  Blockly.FieldDropdown.superClass_.fromXml.call(this, fieldElement);
 };
 
 /**

core/field_multilineinput.js

@@ -105,18 +105,20 @@ Blockly.FieldMultilineInput.prototype.toXml = function(fieldElement) {
   // `Blockly.Xml.domToText` will appear on a single line (this is a limitation
   // of the plain-text format).
   fieldElement.textContent = this.getValue().replace(/\n/g, '
');
+  this.addDisabledToXml_(fieldElement);
   return fieldElement;
 };
 
 /**
- * Sets the field's value based on the given XML element. Should only be
- * called by Blockly.Xml.
+ * Sets the field's value and possibly disables field based on the given XML
+ *     element. Should only be called by Blockly.Xml.
  * @param {!Element} fieldElement The element containing info about the
  *    field's state.
  * @package
  */
 Blockly.FieldMultilineInput.prototype.fromXml = function(fieldElement) {
   this.setValue(fieldElement.textContent.replace(/
/g, '\n'));
+  this.setEnabledFromXml_(fieldElement);
 };
 
 /**

core/field_variable.js

@@ -173,6 +173,7 @@ Blockly.FieldVariable.prototype.fromXml = function(fieldElement) {
   }
 
   this.setValue(variable.getId());
+  this.setEnabledFromXml_(fieldElement);
 };
 
 /**
@@ -190,6 +191,7 @@ Blockly.FieldVariable.prototype.toXml = function(fieldElement) {
   if (this.variable_.type) {
     fieldElement.setAttribute('variabletype', this.variable_.type);
   }
+  this.addDisabledToXml_(fieldElement);
   return fieldElement;
 };