看如下的代码：
/*
* Chained - jQuery / Zepto chained selects plugin
*
* Copyright (c) 2010-2014 Mika Tuupola
*
* Licensed under the MIT license:
* http://www.opensource.org/licenses/mit-license.php
*
* Project home:
* http://www.appelsiini.net/projects/chained
*
* Version: 1.0.0
*
* By Neelie: 增加 data-level 确认父级, 取代 value, 以允许中文值
*
*/
;(function($, window, document, undefined) {
"use strict";
$.fn.chained = function(parent_selector) {
function option_value(el) {
return $("option:selected", el).data('level') || $("option:selected", el).val();
}
return this.each(function() {
/* Save this to child because this changes when scope changes. */
var child = this;
var backup = $(child).clone();
/* Handles maximum two parents now. */
$(parent_selector).each(function() {
$(this).bind("change", function() {
updateChildren();
});
/* Force IE to see something selected on first page load, */
/* unless something is already selected */
if (!$("option:selected", this).length) {
$("option", this).first().attr("selected", "selected");
}
/* Force updating the children. */
updateChildren();
});
function updateChildren() {
var trigger_change = true;
// var currently_selected_value = $("option:selected", child).val();
var currently_selected_value = option_value(child);
$(child).html(backup.html());
/* If multiple parents build classname like foo\bar. */
var selected = "";
$(parent_selector).each(function() {
var selectedClass = option_value(this);
if (selectedClass) {
if (selected.length > 0) {
if (window.Zepto) {
/* Zepto class regexp dies with classes like foo\bar. */
selected += "\\\\";
} else {
selected += "\\";
}
}
selected += selectedClass;
}
});
/* Also check for first parent without subclassing. */
/* TODO: This should be dynamic and check for each parent */
/* without subclassing. */
var first;
if ($.isArray(parent_selector)) {
first = $(parent_selector[0]).first();
} else {
first = $(parent_selector).first();
}
var selected_first = option_value(first);
$("option", child).each(function() {
/* Remove unneeded items but save the default value. */
if ($(this).hasClass(selected) && $(this).val() === currently_selected_value) {
$(this).prop("selected", true);
trigger_change = false;
} else if (!$(this).hasClass(selected) && !$(this).hasClass(selected_first) && $(this).val() !== "") {
$(this).remove();
}
});
/* If we have only the default value disable select. */
if (1 === $("option", child).size() && $(child).val() === "") {
$(child).prop("disabled", true);
} else {
$(child).prop("disabled", false);
}
if (trigger_change) {
$(child).trigger("change");
}
}
});
};
/* Alias for those who like to use more English like syntax. */
$.fn.chainedTo = $.fn.chained;
/* Default settings for plugin. */
$.fn.chained.defaults = {};
})(window.jQuery || window.Zepto, window, document);