/**
 * @author Remy Sharp
 * @date 2008-02-25
 * @url http://remysharp.com/2007/09/18/auto-populate-multiple-select-boxes/
 * @license Creative Commons License - ShareAlike http://creativecommons.org/licenses/by-sa/3.0/
 */

(function ($) {
    $.fn.selectChain = function (options) {
        var defaults = {
            key: "id",
            value: "label"
        };

        var settings = $.extend({}, options, defaults);

        if (!(settings.target instanceof $)) settings.target = $(settings.target);

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

            $$.change(function () {
                var data = null;
                if (typeof settings.data == 'string') {
                    data = settings.data + '&' + this.name + '=' + $$.val();
                } else if (typeof settings.data == 'object') {
                    data = settings.data;
                    data[this.name] = $$.val();
                }

                settings.target.empty();

                if (settings.loadingMessage) {
                    o = document.createElement("OPTION");
                    o.value = "";
                    o.text = settings.loadingMessage;
                    settings.target.get(0).options[0] = o;
                }

                $.ajax({
                    url: settings.url,
                    data: data,
                    type: (settings.type || 'get'),
                    dataType: 'json',
                    success: function (j) {
                        settings.target.empty();

                        var options = [],
                            i = 0,
                            o = null;
                        for (i = 0; i < j.length; i++) {
                            /* required to get around IE bug (http://support.microsoft.com/?scid=kb%3Ben-us%3B276228) */
                            o = document.createElement("OPTION");
                            o.value = typeof j[i] == 'object' ? j[i][settings.key] : j[i];
                            o.text = typeof j[i] == 'object' ? j[i][settings.value] : j[i];
                            settings.target.get(0).options[i] = o;
                        }

                        settings.target.attr('disabled', false);

                        if (settings.selectedValue){
                        	settings.target.find('option[value='+settings.selectedValue+']').attr('selected', true);
                        }
                    },
                    error: function (xhr, desc, er) {
                        /* add whatever debug you want here. */
                        //alert(desc);
                    }
                });
            });
        });
    };
})(jQuery);