Blockly.Xml code cleanup : fields

core/xml.js

@@ -86,6 +86,50 @@ Blockly.Xml.blockToDomWithXY = function(block, opt_noId) {
   return element;
 };
 
+/**
+ * Encode a field as XML.
+ * @param {!Blockly.Field} field The field to encode.
+ * @param {!Blockly.Workspace} workspace The workspace that the field is in.
+ * @return {?Element} XML element, or null if the field did not need to be
+ *     serialized.
+ * @private
+ */
+Blockly.Xml.fieldToDom_ = function(field, workspace) {
+  if (field.name && field.EDITABLE) {
+    var container = goog.dom.createDom('field', null, field.getValue());
+    container.setAttribute('name', field.name);
+    if (field instanceof Blockly.FieldVariable) {
+      var variable = workspace.getVariable(field.getValue());
+      if (variable) {
+        container.setAttribute('id', variable.getId());
+        container.setAttribute('variabletype', variable.type);
+      }
+    }
+    return container;
+  }
+  return null;
+};
+
+/**
+ * Encode all of a block's fields as XML and attach them to the given tree of
+ * XML elements.
+ * @param {!Blockly.Block} block A block with fields to be encoded.
+ * @param {!Element} element The XML element to which the field DOM should be
+ *     attached.
+ * @private
+ */
+Blockly.Xml.allFieldsToDom_ = function(block, element) {
+  var workspace = block.workspace;
+  for (var i = 0, input; input = block.inputList[i]; i++) {
+    for (var j = 0, field; field = input.fieldRow[j]; j++) {
+      var fieldDom = Blockly.Xml.fieldToDom_(field, workspace);
+      if (fieldDom) {
+        element.appendChild(fieldDom);
+      }
+    }
+  }
+};
+
 /**
  * Encode a block subtree as XML.
  * @param {!Blockly.Block} block The root block to encode.
@@ -105,25 +149,8 @@ Blockly.Xml.blockToDom = function(block, opt_noId) {
       element.appendChild(mutation);
     }
   }
-  function fieldToDom(field) {
-    if (field.name && field.EDITABLE) {
-      var container = goog.dom.createDom('field', null, field.getValue());
-      container.setAttribute('name', field.name);
-      if (field instanceof Blockly.FieldVariable) {
-        var variable = block.workspace.getVariable(field.getValue());
-        if (variable) {
-          container.setAttribute('id', variable.getId());
-          container.setAttribute('variabletype', variable.type);
-        }
-      }
-      element.appendChild(container);
-    }
-  }
-  for (var i = 0, input; input = block.inputList[i]; i++) {
-    for (var j = 0, field; field = input.fieldRow[j]; j++) {
-      fieldToDom(field);
-    }
-  }
+
+  Blockly.Xml.allFieldsToDom_(block, element);
 
   var commentText = block.getCommentText();
   if (commentText) {
@@ -583,31 +610,7 @@ Blockly.Xml.domToBlockHeadless_ = function(xmlBlock, workspace) {
         // Titles were renamed to field in December 2013.
         // Fall through.
       case 'field':
-        var field = block.getField(name);
-        var text = xmlChild.textContent;
-        if (field instanceof Blockly.FieldVariable) {
-          // TODO (marisaleung): When we change setValue and getValue to
-          // interact with IDs instead of names, update this so that we get
-          // the variable based on ID instead of textContent.
-          var type = xmlChild.getAttribute('variabletype') || '';
-          var variable = workspace.getVariable(text);
-          if (!variable) {
-            variable = workspace.createVariable(text, type,
-              xmlChild.getAttribute(id));
-          }
-          if (type != null && type !== variable.type) {
-            throw Error('Serialized variable type with id \'' +
-              variable.getId() + '\' had type ' + variable.type + ', and ' +
-              'does not match variable field that references it: ' +
-              Blockly.Xml.domToText(xmlChild) + '.');
-          }
-        }
-        if (!field) {
-          console.warn('Ignoring non-existent field ' + name + ' in block ' +
-                       prototypeName);
-          break;
-        }
-        field.setValue(text);
+        Blockly.Xml.domToField_(block, name, xmlChild);
         break;
       case 'value':
       case 'statement':
@@ -695,6 +698,42 @@ Blockly.Xml.domToBlockHeadless_ = function(xmlBlock, workspace) {
   return block;
 };
 
+/**
+ * Decode an XML field tag and set the value of that field on the given block.
+ * @param {!Blockly.Block} block The block that is currently being deserialized.
+ * @param {string} fieldName The name of the field on the block.
+ * @param {!Element} xml The field tag to decode.
+ * @private
+ */
+Blockly.Xml.domToField_ = function(block, fieldName, xml) {
+  var field = block.getField(fieldName);
+  if (!field) {
+    console.warn('Ignoring non-existent field ' + fieldName + ' in block ' +
+                 block.type);
+    return;
+  }
+
+  var text = xml.textContent;
+  if (field instanceof Blockly.FieldVariable) {
+    // TODO (#1199): When we change setValue and getValue to
+    // interact with IDs instead of names, update this so that we get
+    // the variable based on ID instead of textContent.
+    var type = xml.getAttribute('variabletype') || '';
+    var variable = block.workspace.getVariable(text);
+    if (!variable) {
+      variable = block.workspace.createVariable(text, type,
+        xml.getAttribute('id'));
+    }
+    if (type != null && type !== variable.type) {
+      throw Error('Serialized variable type with id \'' +
+        variable.getId() + '\' had type ' + variable.type + ', and ' +
+        'does not match variable field that references it: ' +
+        Blockly.Xml.domToText(xml) + '.');
+    }
+  }
+  field.setValue(text);
+};
+
 /**
  * Remove any 'next' block (statements in a stack).
  * @param {!Element} xmlBlock XML block element.