jQuery UI Sortable Position

Question

how do i track what position an element is when its position in the list/sortable changes?

Answer 1

From the jQuery UI docs:

All callbacks receive two arguments: The original browser event and a prepared ui object, view below for a documentation of this object (if you name your second argument 'ui'):

ui.helper - the current helper element (most often a clone of the item) 
**ui.position - current position of the helper**
ui.offset - current absolute position of the helper  
ui.item - the current dragged element
ui.placeholder - the placeholder (if you defined one)
ui.sender - the sortable where the item comes from 
            (only exists if you move from one connected list to another)

Answer 2

You can use the ui object provided to the events, specifically you want the stop event, the ui.item property and .index(), like this:

$("#sortable").sortable({
    stop: function(event, ui) {
        alert("New position: " + ui.item.index());
    }
});

You can see a working demo here, remember the .index() value is zero-based, so you may want to +1 for display purposes.