[Solved] DragDrop in Hierarchichal RadGrid => e.DestDataItem is null when dropping on row header / "No records to display" message

[chrbra]

Hi,

I've got a hierarchichal RadGrid with one Detail Table. Lets call the items on the upper level "boxes" and the ones in the detail table "apples" - which is quite near reality in this case. (only we're not actually tracking apples ;-))

The user can move one or more different apples from one to another box via DragDrop.

This works fine when the apples are dropped on a specific box: Then I get a e.DestDataItem from the RadGrid1_RowDrop(object sender, GridDragDropEventArgs e) event, and I can figure out which box the apple(s) were placed in.

It also works fine, when there are already apples in a box, and some other apples are dropped on these rows. Then again I get a e.DestDataItem, and I can figure out, which box these apples are in, and I can add the dragged apples to the same box.

BUT: If apples are dropped either on the header rows of the DetailTable, or if a box is empty and they are dropped on the "No child records to display", then the e.DestDataItem is null. This sort of makes sense, but in this case I need a reference to the box, so I can add the dragged apples to this box.
I spent almost an hour now inspecting the GridDragDropEventArgs I get in this case, and I can nowhere find a reference. As soon as the DestDataItem is null, there seems to be no way of finding out which box the apples were dragged on.

The DestinationGrid and DestinationTableView Members are both not-null, so maybe I am missing something.
Any help is appreciated.

Best,
Christian

[Angel Petrov]

Hello Christian,

When dropping over a table view which does not contain records it is expected the e.DestDataItem to be null In this case I suggest that you use the e.DestinationTableView instead as it returns a reference to the GridTableView over which the drop has occurred.(in the particular case the table view which has no records). As for dropping a record on a header row I suggest that you obtain a reference on the client to the GridTableView which holds this header. This can be achieved using the code snippet below:

function onRowDropping(sender, args) {
           var GridTableView = Telerik.Web.UI.Grid.GetFirstParentByTagName(args.get_destinationHtmlElement(), "table");
           var tableView = $find(GridTableView.id);
       }

Note that when a row is dropped over the header the server-side OnRowDrop will not fire. That said the adding/removing of items should be done client-side.

Regards,
Angel Petrov
Telerik