/*jquery.cascade.js */
/*
 * jQuery UI cascade
 * version: 1.1.1 (6/16/2008)
 * @requires: jQuery v1.2 or later
 * adapted from Yehuda Katz, Rein Henrichs autocomplete plugin
 * Dual licensed under the MIT and GPL licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
 *
 * Copyright 2008 Mike Nichols

 */

;(function($) {

  $.ui = $.ui || {}; $.ui.cascade = $.ui.cascade || {};

  $.fn.cascade = function(parent,opt) {
        if( opt.event ){
                //namespace our event
                opt.event = opt.event.replace('.cascade','') + '.cascade';
        }

    opt = $.extend({}, {
                list: [], //static list to use as datasource
                timeout: 10,//delay before firing getList operation
                getList: function(select) { $(this).trigger("updateList", [opt.list]); }, //function to fetch datasource
                template: function(str) { return "<option value='" + str + "'>" + str + "</option>"; },//applied to each item in datasource
                match: function(selectedValue) { return true;}, //'this' is the js object, or the current list item from 'getList',
                event: "change.cascade",        //event to listen on parent which fires the cascade
                getParentValue: function(parent) { return $(parent).val(); } //delegate for retrieving the parent element's value
    }, opt);

    if($.ui.cascade.ext) {
                for(var ext in $.ui.cascade.ext) {
                if(opt[ext]) {
                  opt = $.extend(opt, $.ui.cascade.ext[ext](opt));
                  delete opt[ext];
                }
                }
        }

    return this.each(function() {
                var source = $(parent);
                var self = $(this);

                //bind any events in extensions to each instance
                if($.ui.cascade.event) {
                        for(var e in $.ui.cascade.event) {
                                self.bind(e + ".cascade",[source],$.ui.cascade.event[e]);
                        }
                }

                $(source).bind(opt.event,function() {
                        self.trigger("loading.cascade",[source[0]]);

                        var selectTimeout = $.data(self, "selectTimeout");
                        if(selectTimeout) { window.clearInterval(selectTimeout); }
                        $.data(self, "selectTimeout", window.setTimeout(function() {
                                        self.trigger("cascade");
                        }, opt.timeout));

                });

        self.bind("cascade", function() {
          self.one("updateList", function(e, list) {
            list = $(list)
              .filter(function() { return opt.match.call(this, opt.getParentValue(parent)); })
              .map(function() {
                var node = $(opt.template(this))[0];
                return node;
              });

                        self.empty();//clear the source/select

            if(list.length){
                                self.html(list);
                        }

                        self.trigger("loaded.cascade",[source[0]]);//be sure to fire even if there is no data

                        if( self.is(":input") ) { //opinionated , but  enables cascading from this element as  well
                                self.trigger("change.cascade");
                        }
          });

          opt.getList.call(self[0],source);     //call with child element as this

        });
    });
  };

})(jQuery);