javascript全局变量封装模块实现代码
javascript全局变量封装模块实现代码
发布时间:2016-12-30 来源:查字典编辑
摘要:下面的代码是我的测试代码,注释很重要:复制代码代码如下:/*globalwindow,jQuery,validate_email,maste...

下面的代码是我的测试代码,注释很重要:

复制代码 代码如下:

/*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:

复制代码 代码如下:

[plain] view plaincopyprint?

<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:

复制代码 代码如下:

[javascript] view plaincopyprint?}(window, document)); }(window, document));

无所谓了,就任由它吧。只要功能正常就行。

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