Seaside jQuery - Sorting a list with drag and drop and sending it back via Ajax causes OrderedCollection to turn into an Array?

Question

The code below is form the Seaside book at: http://book.seaside.st/book/web-20/jquery/enhanced-todo-application/drag-and-drop

html jQuery new sortable
    onStop:
            (html jQuery ajax
                    callback: [ :items | modelRole getModelRolePlayer setItemList: items ]
                    passengers: (html jQuery this find: 'li'));
    axis: 'y'

My instance variable _itemList is initially OrderedCollection. As soon as I move the rows around in the page then entire list is sent back in it's new order. However, this time setItemList: receives an Array.

Does this make any sense? Am I missing something?

Answer 1

So the problem is that #callback:passenger: uses #subStrings: to get the element ids from the AJAX callback and then does a #collect: on that collection to determine the Smalltalk objects. Since #subStrings: returns an array, the #collect: will also return an array.

The solution: send #asOrderedCollection to the array before storing it:

(html jQuery ajax
  callback: [ :items | modelRole getModelRolePlayer setItemList: items asOrderedCollection ]
  passengers: (html jQuery this find: 'li'));