source: src/django_gheat/wlheatmap/static/jquery.chained.js@ 9381

/*
 * Chained - jQuery non AJAX(J) chained selects plugin
 *
 * Copyright (c) 2010 Mika Tuupola
 *
 * Licensed under the MIT license:
 *   http://www.opensource.org/licenses/mit-license.php
 *
 */

(function($) {

    $.fn.chained = function(parent_selector, options) { 
        
        return this.each(function() {
            
            /* Save this to self because this changes when scope changes. */            
            var self   = this;
            var backup = $(self).clone();
                        
            /* Handles maximum two parents now. */
            $(parent_selector).each(function() {
                                                
                $(this).bind("change", function() {
                    $(self).html(backup.html());

                    /* If multiple parents build classname like foo\bar. */
                    var selected = "";
                    $(parent_selector).each(function() {
                        selected += "\\" + $(":selected", this).val();
                    });
                    selected = selected.substr(1);

                    /* Also check for first parent without subclassing. */
                    /* TODO: This should be dynamic and check for each parent */
                    /*       without subclassing. */
                    var first = $(parent_selector).first();
                    var selected_first = $(":selected", first).val();
                
                    $("option", self).each(function() {
                        /* Remove unneeded items but save the default value. */
                        if (!$(this).hasClass(selected) && 
                            !$(this).hasClass(selected_first) && $(this).val() !== "") {
                                $(this).remove();
                        }                        
                    });
                
                    /* If we have only the default value disable select. */
                    if (1 == $("option", self).size() && $(self).val() === "") {
                        $(self).attr("disabled", "disabled");
                    } else {
                        $(self).removeAttr("disabled");
                    }
                    $(self).trigger("change");
                });
                
                /* Force IE to see something selected on first page load. */
                $("option", this).first().attr("selected", "selected");
                
                /* Force updating the children. */
                $(this).trigger("change");             

            });
        });
    };
    
    /* Alias for those who like to use more English like syntax. */
    $.fn.chainedTo = $.fn.chained;
    
})(jQuery);