Attaching jQuery event handlers so that they are triggered first

Question

Is there a way to attach a jQuery event handler such that the handler is triggered before any previously-attached event handlers? I came across this article, but the code didn't work because event handlers are no-longer stored in an array, which is what his code expected. I attempted to create a jQuery extension to do what I wanted, but this is not working (the events still fire in the order they were bound):

$.fn.extend({
    bindFirst: function(type, handler) {

        var baseType = type;
        var dotIdx = type.indexOf('.');
        if (dotIdx >= 0) {
            baseType = type.substr(0, dotIdx);
        }

        this.each(function() {
            var oldEvts = {};
            var data = $.data(this);
            var events = data.events || data.__events__;
            var handlers = events[baseType];
            for (var h in handlers) {
                if (handlers.hasOwnProperty(h)) {
                    oldEvts[h] = handlers[h];
                    delete handlers[h];
                    // Also tried an unbind here, to no avail
                }
            }

            var self = $(this);
            self.bind(type, handler);

            for (var h in oldEvts) {
                if (oldEvts.hasOwnProperty(h)) {
                    self.bind(baseType, oldEvts[h]);
                }
            }
        });
    }
});

Is there a natural way to reorder event handling? If there isn't, do you know of technique I could apply? I'm using jQuery 1.4.1, though I'll upgrade if I must.

question from:https://stackoverflow.com/questions/4742610/attaching-jquery-event-handlers-so-that-they-are-triggered-first

Answer 1

Here's a simple plugin I did a while back. Lets you bind a handler to the beginning of the list. It is very simple, and I wouldn't guarantee that it works with namespaced events or anything terribly fancy.

For simply binding a single or space separate group of events, it should work.

Example: http://jsfiddle.net/gbcUy/

$.fn.bindUp = function(type, fn) {

    type = type.split(/s+/);

    this.each(function() {
        var len = type.length;
        while( len-- ) {
            $(this).bind(type[len], fn);

            var evt = $.data(this, 'events')[type[len]];
            evt.splice(0, 0, evt.pop());
        }
    });
};

Or if you wanted to manipulate the Array of handlers in some other manner, just get the handlers for the element you want, and manipulate it however you want:

Example: http://jsfiddle.net/gbcUy/1/

var clickHandlers = $('img').data('events').click;

clickHandlers.reverse(); // reverse the order of the Array