Question

I’ve got two dojo.dnd.Sources with items. Whenever an item is dropped I need to persist the new order of the items in the Sources using an xhr.

Is there an dojo event or topic that is fired after an dnd operation has (successfully) finished? What would be the best way to use it?

Answer 1

Probably I don’t understand the problem in all details but I don’t see why you need to process events or topics. The best way to record changes is to intercept updating methods on relevant sources. Specifically you need to intercept insertNodes() for drops or any other additions.

Simple example (pseudo-code):

var source1, source2;
// ...
// initialize sources
// populate sources
// ...

function getAllItems(source){
  var items = source.getAllNodes().map(function(node){
    return source.getItem(node.id);
  });
  return items;
}

function dumpSource(source){
  var items = getAllItems(source);
  // XHR items here to your server
}

function recordChange(){
  // now we know that some change has occured
  // it could be a drop or some programmatic updates
  // we don't really care
  dumpSource(source1);
  dumpSource(source2);
}

dojo.connect(source1, "insertNodes", recordChanges);
dojo.connect(source2, "insertNodes", recordChanges);
// now any drop or other change will trigger recordChanges()
// after the change has occurred.

You can try to be smart about that and send some diff information instead of a whole list, but it is up to you to generate it — you have everything you need for that.