Getting the position of the element in a list when it's drag/dropped (ui.sortable)

Question

I have a sortable list like this one: http://jqueryui.com/demos/sortable

Is it possible to get the start and end position of the element in the list, when it has been moved? I'm talking about their position number, in the list.

For example, if I move element 2 to position 5 in the list, I'd like to assign those two numbers to variables.

I'm new to jQuery - any help would be much appreciated.

Solution 1

• demo: http://so.lucafilosofi.com/getting-the-position-of-the-element-in-a-list-when-its-drag-dropped-ui-sortable/

SOLUTION:

$(function() {
    $('ul#sortable').sortable({
        start: function(event, ui) {
            var start_pos = ui.item.index();
            ui.item.data('start_pos', start_pos);
        },
        update: function(event, ui) {
            var start_pos = ui.item.data('start_pos');
            var end_pos = ui.item.index();
            alert(start_pos + ' - ' + end_pos);
        }
    });
});

• NOTE: Updated to make use of jQuery data() method under advice of Alconja

Solution 2

I believe what you are looking to do is done with the serialize method. Serialize is get the new order of the list.

Solution 3

For some reason ui.item.index() did not work for me.

This did:

update: function (event, ui) 
{
    var index = $('li', $(ui.item).parent()).index(ui.item);
    alert(index);
}

Comments

[Marijn Huizendveld]

This is such a great example of the terrible API design of jQuery UI

[Mottie]

+1 Nice concise answer, but you don't need to wrap the ui.item, it's already a jQuery object. So instead of $(ui.item) use ui.item

[Wurlitzer]

Elegant answer! Thank you so much. I guess the ui.item object is what I was looking for, here.

[Alconja]

+1, although you should probably use ui.item.data('start_pos', start_pos); in start and var start_pos = ui.item.data('start_pos'); in update rather than polluting the id.