Implementing Dirty Flag for a generated Model (Flex 4)

Question

Hi there,
I try to implement a dirty flag for a model generated by a Data Binding Wizard. I tried several ways but always failed to get it work properly bounded to the 'enabled' property of a button. Is there a "best approach" to implement this in a by Flex 4 generated model?
I have all the Form elements bound to the model's properties and defined fx:Bindings on the model's property as well to get the changes back to the model as well.
-> I tried to listen to the properyChange event on the Super model but I always returned true for the Dirty flag and couldn't set it to false when I loaded the model into a Form.
-> I tried to implement a similar approach like below, instead of doing a normal 'getter' function on the isDirty flag I bounded it to the propertyChange event, it failed exactly the same way as above
I did used my own solution earlier like this:
[RemoteClass(alias="VODictionaryEntry")]
     [Bindable]
     public class VODictionaryEntry
               private var _id:Number = 0;
               private var _terminology:String;
               private var _description:String;
               private var _notes:String;
               private var _insert_date:String;
               private var _update_date:String;
               private var _vendor_related:Boolean;
               public var isDirty:Boolean = false;
               public function get vendor_related():Boolean
                    return _vendor_related;
               public function set vendor_related(value:Boolean):void
                    _vendor_related = value;
                    isDirty = true;
               public function get update_date():String
                    return _update_date;
               public function set update_date(value:String):void
                    _update_date = value;
                    isDirty = true;
               public function get insert_date():String
                    return _insert_date;
               public function set insert_date(value:String):void
                    _insert_date = value;
                    isDirty = true;
               public function get notes():String
                    return _notes;
               public function set notes(value:String):void
                    _notes = value;
                    isDirty = true;
               public function get description():String
                    return _description;
               public function set description(value:String):void
                    _description = value;
                    isDirty = true;
               public function get terminology():String
                    return _terminology;
               public function set terminology(value:String):void
                    _terminology = value;
                    isDirty = true;
               public function get id():Number
                    return _id;
               public function set id(value:Number):void
                    _id = value;
                    isDirty = true;
this is a very simple solution but it worked like a charm. Can somebody suggest me something else, a better solution?
thank you
r. Sandor
P.S.: I didn't include the validators to simplify the example.

Answer 1

hi,
meanwhile I come a little bit further if you implement the isDirty flag into your remote model and let generate ( to be included in the flex model as well) a model with Flex you can listen to the propertyChange event and do implement a correctly functioning bindable property.
public function VOMessageEntry():void
     addEventListener( PropertyChangeEvent.PROPERTY_CHANGE, handlePropertyChange );
private function handlePropertyChange( event:PropertyChangeEvent ):void
     if ( event.property != "isDirty" )
          isDirty = true;
this code must be inserted into the generated Object itself not in the _Super_objectname source code.
I hope I could helped somebody with this solution.
r. Sandor