JavaScript用匿名闭包封装模块

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下面的代码是我的测试代码，注释很重要：

/*global window,jQuery,validate_email,masterUI,$,rest*//** Enable ECMAScript "strict" operation for this function. See more:                                                                                                              * http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/                                                                                                                  * http://stackoverflow.com/questions/5020479/what-advantages-does-using-functionwindow-document-undefined-windo                                                                  * Q1: Why are window and document being fed instead of just being accessed normally?                                                                                             * A1: Generally to fasten the identifier resolution process, having them as local variables can help (although IMO the performance improvements may be negligible).              * A2: Passing the global object is also a widely used technique on non-browser environments, where you don't have a window identifier at the global scope, e.g.:                 * (function (global) {                                                                                                                                                           *  //..                                                                                                                                                                          * })(this); // this on the global execution context is the global object itself                                                                                                  * A3: Passing window and document allows the script to be more efficiently minified                                                                                              *                                                                                                                                                                                * Q2: Why the heck is undefined being passed in?                                                                                                                                 * A1: This is made because the undefined global property in ECMAScript 3, is mutable, meaning that someone could change its value affecting your code, for example:              * undefined = true; // mutable                                                                                                                                                   * (function (undefined) {                                                                                                                                                        * alert(typeof undefined); // "undefined", the local identifier                                                                                                                  * })(); // <-- no value passed, undefined by default                                                                                                                             * If you look carefully undefined is actually not being passed (there's no argument on the function call),                                                                       * that's one of the reliable ways to get the undefined value, without using the property window.undefined.                                                                       *                                                                                                                                                                                */(function(window, document, undefined) {    "use strict";    window.test = {        init: function () {            "use strict";            alert("ok");        }    };})(window, document);// no undefined parameter here to avoid using mutable window.undefined changed by other guy

1.说明，参考了一篇文章和stackoverflow上的一个帖子

2.(function(){})() 这种代码写在独立的js文件里，当js文件被html加载的时候，该函数就会执行。实际上创建了windows.text对象。

以后html代码就可用test.init的形式调用方法。

测试html部分代码如下：

  <head>    <title>AppEngine SDK</title>    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">    <script type="text/javascript" src="../../master/script/third_party/jquery-1.8.0.min.js"></script>    <script type="text/javascript" src="../../master/plugin/jquery-validation-1.9.0/jquery.validate.js"></script>    <script type="text/javascript" src="../../master/plugin/artDialog4.1.6/jquery.artDialog.js"></script>    <script type="text/javascript" src="../../master/script/app/test.js"></script>    <script type="text/javascript">      $(document).ready(function() {      test.init();      })    </script>  </head>

3.Jslint会报两个问题，一是关于undefined的，没找到什么好方法，任它抱怨吧。另一格式最后调用方式要改成：

}(window, document));

无所谓了，就任由它吧。只要功能正常就行。

最后推荐一篇文章，前面的基础部分非常清晰的描述了anonymous closures 的使用。搞JavaScript的朋友看看会很有帮助。

http://www.adequatelygood.com/2010/3/JavaScript-Module-Pattern-In-Depth