Changed `onMoving` to be a callback by default (simpler code, little performance hit) See also #294

HISTORY.md

@@ -36,6 +36,7 @@ http://visjs.org
   account).
 - Renamed internal items from `ItemBox`, `ItemRange`, and `ItemPoint` to
   respectively `BoxItem`, `RangeItem`, and `PointItem`.
+- Fixed an error thrown when calling `destroy()`.
 
 
 ## 2014-08-29, version 3.3.0

docs/timeline.html

@@ -563,6 +563,14 @@ var options = {
     </td>
 </tr>
 
+<tr>
+    <td>onMoving</td>
+    <td>Function</td>
+    <td>none</td>
+    <td>Callback function triggered repeatedly when an item is being moved. See section <a href="#Editing_Items">Editing Items</a> for more information. Only applicable when both options <code>selectable</code> and <code>editable.updateTime</code> or <code>editable.updateGroup</code> are set <code>true</code>.
+    </td>
+</tr>
+
 <tr>
     <td>onRemove</td>
     <td>Function</td>

lib/timeline/component/ItemSet.js

@@ -51,7 +51,9 @@ function ItemSet(body, options) {
     onRemove: function (item, callback) {
       callback(item);
     },
-    onMoving: null,  // onMoving is null by default for better performance (other on* functions do not support null)
+    onMoving: function (item, callback) {
+      callback(item);
+    },
 
     margin: {
       item: {
@@ -1127,22 +1129,15 @@ ItemSet.prototype._onDrag = function (event) {
         newProps.group = group && group.groupId;
       }
 
-      if (me.options.onMoving) {
-        var itemData = util.extend({}, props.item.data, newProps);
-
-        me.options.onMoving(itemData, function (itemData) {
-          if (itemData) {
-            me._updateItemProps(props.item, itemData);
-          }
-        });
-      }
-      else {
-        me._updateItemProps(props.item, newProps);
-      }
+      // confirm moving the item
+      var itemData = util.extend({}, props.item.data, newProps);
+      me.options.onMoving(itemData, function (itemData) {
+        if (itemData) {
+          me._updateItemProps(props.item, itemData);
+        }
+      });
     });
 
-    // TODO: implement onMoving handler
-
     this.stackDirty = true; // force re-stacking of all items next redraw
     this.body.emitter.emit('change');