urlyar/assets/js/jquery.ajaxq.js

/*
 * jQuery AjaxQ - AJAX request queueing for jQuery
 *
 * Version: 0.0.1
 * Date: July 22, 2008
 *
 * Copyright (c) 2008 Oleg Podolsky (oleg.podolsky@gmail.com)
 * Licensed under the MIT (MIT-LICENSE.txt) license.
 *
 * http://plugins.jquery.com/project/ajaxq
 * http://code.google.com/p/jquery-ajaxq/
 */

jQuery.ajaxq = function (queue, options) {
    // Initialize storage for request queues if it's not initialized yet
    if (typeof document.ajaxq == "undefined") document.ajaxq = {q: {}, r: null};

    // Initialize current queue if it's not initialized yet
    if (typeof document.ajaxq.q[queue] == "undefined") document.ajaxq.q[queue] = [];

    if (typeof options != "undefined") // Request settings are given, enqueue the new request
    {
        // Copy the original options, because options.complete is going to be overridden

        var optionsCopy = {};
        for (var o in options) optionsCopy[o] = options[o];
        options = optionsCopy;

        // Override the original callback

        var originalCompleteCallback = options.complete;

        options.complete = function (request, status) {
            // Dequeue the current request
            document.ajaxq.q[queue].shift();
            document.ajaxq.r = null;

            // Run the original callback
            if (originalCompleteCallback) originalCompleteCallback(request, status);

            // Run the next request from the queue
            if (document.ajaxq.q[queue].length > 0) document.ajaxq.r = jQuery.ajax(document.ajaxq.q[queue][0]);
        };

        // Enqueue the request
        document.ajaxq.q[queue].push(options);

        // Also, if no request is currently running, start it
        if (document.ajaxq.q[queue].length == 1) document.ajaxq.r = jQuery.ajax(options);
    }
    else // No request settings are given, stop current request and clear the queue
    {
        if (document.ajaxq.r) {
            document.ajaxq.r.abort();
            document.ajaxq.r = null;
        }

        document.ajaxq.q[queue] = [];
    }
}