Question

I’ve written a function to call the default jQuery.fn.on-handler, after a given number of fired events. Now I stuck, because the original event will not passed to the function, any ideas how to improve this?

;(function ($) {
    var oldOn = $.fn.on,
        i = 0;
    $.fn.on = function () {
        var args = arguments,
            j = args.length;

        for (var last in args);

        while (j--) {
            if ($.isFunction(args[j]) && !isNaN(args[last])) {
                var oldFn = args[j],
                    after = args[last];
                args[j] = function () {
                    i++;
                    if (i === after) {
                        oldFn.call();
                        i = 0;
                    }
                };
            }
        }

        if (!isNaN(args[last])) delete args[last];
        return oldOn.apply(this, arguments);
    };
})(jQuery);

// call the plugin and fire the `fn` after each 20 mousemoves
$(document).on('mousemove', function (e) {
    console.log(e); // undefined
}, 20);

As you can see, will the following work without problems:

var oldOn = $.fn.on;
$.fn.on = function () {
    return oldOn.apply(this, arguments);
};

$(document).on('click', function(e){
    console.log(e) // jQuery.Event
});

Where’s the mistake, how can i get this to work?

Update

I got it much simpler now: https://github.com/yckart/jquery.unevent.js

Answer 1

You’re not passing the arguments from your callback wrapper function to the original callback function.

args[j] = function (*HERE*) {
  i++;
  if (i === after) {
    oldFn.call(*TO HERE*);
    i = 0;
  }
};

Try replacing oldFn.call(); with oldFn.apply(this, [].slice.call(arguments)); to carry them over (and keeping up jQuery’s this).

Edit: http://jsfiddle.net/QFyhX/