jQuery Sortable - Limit number of items in list

To have the function fire every time that you try to drag a new item into a specific list (dynamically) you need to use on() rather than the receive: method.

http://jqueryui.com/demos/sortable/#event-receive

$(function() {
    $( "#day1, #day2" ).sortable({
        connectWith: ".connectedSortable"
    }).disableSelection();

    $( "#day1" ).on( "sortreceive", function(event, ui) {
        if($("#day1 li").length > 10){
            $(ui.sender).sortable('cancel');
        }
    });

});

• DEMO: http://so.lucafilosofi.com/jquery-sortable-limit-number-of-items-in-list

$(function() {
    $(".sortables").sortable({
        connectWith: '.connectedSortable',
        //receive: This event is triggered when a
        //connected sortable list has received an item from another list.
        receive: function(event, ui) {
            // so if > 10
            if ($(this).children().length > 10) {
                //ui.sender: will cancel the change.
                //Useful in the 'receive' callback.
                $(ui.sender).sortable('cancel');
            }
        }
    }).disableSelection();
});