Question

An absolutely common sortable case:

<script>
$(function() {
  $("#sortable").sortable();
});
</script>

<ul id="sortable">
  <li>Item 1</li>
  <li>Item 2</li>
  <li>Item 3</li>
</ul>

Problem. Need to cancel dragging of an item on some condition and there is a good advice of Andrew Whitaker, but that approach is working only for jquery-ui-draggable and fails for sortables:

$("#sortable").sortable({
  start: function() {
    return false; // will still cause `this.helper is null`
  }
});

Will be greateful for suggestions.

Answer 1

The sort function callback does the same for sort as drag for draggable (demo):

$("#sortable").sortable({
    sort: function() {
        if ($(this).hasClass("cancel")) {
            $(this).sortable("cancel");
        }
    }
});