Question

I’m using JqueryUI to drag and drop to a sortable list. Suppose coll-selected-list is the list I want to drop on, I want to check if the current item I’m dropping exists in the list already. If it does, I wish to prevent the drop. Is this possible? My code is below:

$("#coll-selected-list").sortable({
        receive: function (event, ui) {
            //alert($(ui.item).text());

            var itemName = $(ui.item).text();
        if ($("#coll-selected-list li:contains(" + itemName + ")")) {
               //DO Nothing 
            }

        }
    });

Answer 1

You can use the cancel() method:

$("#coll-selected-list").sortable({
    receive: function (event, ui) {
        var itemName = ui.item.text();
        if ($("#coll-selected-list li:contains(" + itemName + ")").length) {
            $(this).sortable("cancel");
        }
    }
});