Add Store.hasChanges

src/mesh/model/store/Commits.as

@@ -68,9 +68,11 @@ package mesh.model.store
 		 */
 		public function commit(entities:Array = null):void
 		{
-			entities = (entities == null || entities.length == 0) ? _changes.toArray() : intersection(entities, _changes.toArray());
-			_changes.removeAll(entities);
-			queue( new Commit(_store, snapshot(entities)) );
+			if (_store.hasChanges) {
+				entities = (entities == null || entities.length == 0) ? _changes.toArray() : intersection(entities, _changes.toArray());
+				_changes.removeAll(entities);
+				queue( new Commit(_store, snapshot(entities)) );
+			}
 		}
 
 		private function commitFailed(commit:Commit):void

src/mesh/model/store/Store.as

@@ -8,6 +8,8 @@ package mesh.model.store
 	import mesh.model.Entity;
 	import mesh.model.source.Source;
 
+	import mx.events.PropertyChangeEvent;
+
 	/**
 	 * The store represents a repository for all <code>Entity</code>s in your application. The store
 	 * is assigned a data source, which is responsible for persisting the changes to each entity.
@@ -113,12 +115,16 @@ package mesh.model.store
 
 		private function handleEntityStatusStateChange(event:StateEvent):void
 		{
+			var oldHasChanges:Boolean = hasChanges;
+
 			var entity:Entity = Entity( event.target );
 			if (entity.status.isDirty) {
 				_changes.add(entity);
 			} else if (entity.status.isSynced) {
 				_changes.remove(entity);
 			}
+
+			dispatchEvent(PropertyChangeEvent.createUpdateEvent(this, "hasChanges", oldHasChanges, hasChanges));
 		}
 
 		private function register(entity:Entity):void
@@ -176,6 +182,15 @@ package mesh.model.store
 			return _dataSource;
 		}
 
+		[Bindable(event="propertyChange")]
+		/**
+		 * <code>true</code> if the store has uncommitted changes.
+		 */
+		public function get hasChanges():Boolean
+		{
+			return _changes.length > 0;
+		}
+
 		private var _index:EntityIndex;
 		/**
 		 * The internal index of <code>Entity</code>s used by the store.