/**

 * jQuery Once Plugin v1.2

 * http://plugins.jquery.com/project/once

 *

 * Dual licensed under the MIT and GPL licenses:

 *   http://www.opensource.org/licenses/mit-license.php

 *   http://www.gnu.org/licenses/gpl.html

 */

(function ($) {

  var cache = {}, uuid = 0;

  /**

   * Filters elements by whether they have not yet been processed.

   *

   * @param id

   *   (Optional) If this is a string, then it will be used as the CSS class

   *   name that is applied to the elements for determining whether it has

   *   already been processed. The elements will get a class in the form of

   *   "id-processed".

   *

   *   If the id parameter is a function, it will be passed off to the fn

   *   parameter and the id will become a unique identifier, represented as a

   *   number.

   *

   *   When the id is neither a string or a function, it becomes a unique

   *   identifier, depicted as a number. The element's class will then be

   *   represented in the form of "jquery-once-#-processed".

   *

   *   Take note that the id must be valid for usage as an element's class name.

   * @param fn

   *   (Optional) If given, this function will be called for each element that

   *   has not yet been processed. The function's return value follows the same

   *   logic as $.each(). Returning true will continue to the next matched

   *   element in the set, while returning false will entirely break the

   *   iteration.

   */

  $.fn.once = function (id, fn) {

    if (typeof id != 'string') {

      // Generate a numeric ID if the id passed can't be used as a CSS class.

      if (!(id in cache)) {

        cache[id] = ++uuid;

      }

      // When the fn parameter is not passed, we interpret it from the id.

      if (!fn) {

        fn = id;

      }

      id = 'jquery-once-' + cache[id];

    }

    // Remove elements from the set that have already been processed.

    var name = id + '-processed';

    var elements = this.not('.' + name).addClass(name);

    return $.isFunction(fn) ? elements.each(fn) : elements;

  };

  /**

   * Filters elements that have been processed once already.

   *

   * @param id

   *   A required string representing the name of the class which should be used

   *   when filtering the elements. This only filters elements that have already

   *   been processed by the once function. The id should be the same id that

   *   was originally passed to the once() function.

   * @param fn

   *   (Optional) If given, this function will be called for each element that

   *   has not yet been processed. The function's return value follows the same

   *   logic as $.each(). Returning true will continue to the next matched

   *   element in the set, while returning false will entirely break the

   *   iteration.

   */

  $.fn.removeOnce = function (id, fn) {

    var name = id + '-processed';

    var elements = this.filter('.' + name).removeClass(name);

    return $.isFunction(fn) ? elements.each(fn) : elements;

  };

})(jQuery);