Flex Advanced Data Grid w/ hierarchical data: How to access currentTarget fields on dragdrop event?

Question

So this is driving me crazy. I've got an advanced data grid with a dataprovider that's an array collection w/ hierarchical data. Each object (including the children) has an id field. I'm trying to drag and drop data from within the ADG. When this happens, I need to grab the id off the drop target and change the dragged object's parentid field. Here's what I've got:

public function topAccountsGrid_dragDropHandler(event:DragEvent):void{  
    //In this function, you need to make the move, update the field in salesforce, and refresh the salesforce data...
    if(checkActivateAccountManageMode.selected == true) {
        var dragObj:Array = event.dragSource.dataForFormat("treeDataGridItems") as Array;
        var newParentId:String = event.currentTarget['Id'];
        dragObj[0].ParentId = newParentId;
    } else {
        return;
    }
    app.wrapper.save(dragObj[0], 
        new mx.rpc.Responder(
            function():void {
            refreshData();
        },
        function():void{_status = "apex error!";}
        )
    );
}

I can access the data I'm draggin (hence changing parentId) but not the currentTarget. I think the hierarchical data is part of the problem, but I can't find much in the documentation? Any thoughts?

Answer 1

event.currentTarget is not a node, it's the ADG itself. However, it's quite easy to get the information you want, since the ADG stores that data internally (as mx_internal).

I'm using the following code snippets (tested with Flex SDK 4.1) in a dragOver handler, but I guess it will work in a dragDrop handler too.

protected function myGrid_dragDropHandler(event:DragEvent):void
{
    // Get the dragged items. This could either be an Array, a Vector or NULL.
    var draggedItems:Object = getDraggedItems(event.dragSource);

    if (!draggedItems)
        return;

    // That's our ADG where the event handler is registered.
    var dropTarget:AdvancedDataGrid = AdvancedDataGrid(event.currentTarget);

    // Get the internal information about the dropTarget from the ADG.
    var dropData:Object = mx_internal::dropTarget._dropData;

    // In case the dataProvider is hierarchical, get the internal hierarchicalData aka rootModel.
    var hierarchicalData:IHierarchicalData = dropTarget.mx_internal::_rootModel;
    var targetParent:Object = null;

    // If it's a hierarchical data structure and the dropData could be retrieved
    // then get the parent node to which the draggedItems are going to be added.
    if (hierarchicalData && dropData)
        targetParent = dropData.parent;

    for each (var draggedItem:Object in draggedItems)
    {
        // do something with the draggedItem
    }
}

protected function getDraggedItems(dragSource:DragSource):Object
{
    if (dragSource.hasFormat("treeDataGridItems"))
        return dragSource.dataForFormat("treeDataGridItems") as Array;

    if (dragSource.hasFormat("items"))
        return dragSource.dataForFormat("items") as Array;

    if (dragSource.hasFormat("itemsByIndex"))
        return dragSource.dataForFormat("itemsByIndex") as Vector.<Object>;

    return null;
}

Answer 2

var dropData:Object = mx_internal::dropTarget._dropData; 

should be

var dropData:Object = dropTarget.mx_internal::_dropData;

Try this.