了解JS Module Pattern的工作原理

Question

我正在尝试理解jQuery中使用的js模块模式.我已经编辑了几次,并试图在我的技能水平上做一个很好的练习(几个月新鲜的jquery).

这篇文章没有直接的问题.我更瞄准如何在大型网站中正确使用模块模式(与jquery一起)的反馈和输入.

更新:我添加了一些示例,以便全面了解所有编写内容的方法,并尝试覆盖任何陷阱.

/* 
Not all browsers works with console.log, so we want to make sure that
console.log is defined. This defines the consol.log and send the messages
into an alert.
*/
if(!window.console) console = {
  log: function(s) { 
    alert(s); // alert since we dont have the firebug console
  }
};

// Check if namespace is defined
if (typeof (CompanyName) === 'undefined') {
    CompanyName = {};
}

// Or if AppName under CompanyName...

if (typeof (CompanyName.AppName) === 'undefined') {
    CompanyName.AppName = {};
}

// Our namespace
CompanyName.AppName = (function ($) {

    // CHAINING
    var _first = function () {
        // Important to always start with "var"
    },

    _second = function () {
        // Chained (  ...},  ) so it doesnt need "var"
    },

    _third = "Just a var", // Variables just ends with ,

    _four = "Another var"; // Closing the chain with ;

    var _anotherFirst = function () {
        // Previous chain of var's was ended with ; so this var needed "var" in order to start.
    };

    g_globalVar = "I'm free!"; // When starting a var without "var", it becomes global.

    g_globalMethod = function () { 
        alert("I'm free too!"); // Global method.
    };

    g_chainedGlobalVarOne = "We are free!",
    g_chainedGlobalVarTwo = "We are free!";

    // Private Variables
    var _privateVar = "privateVar: accessed from within AppLaunch.Admin namespace";

    // Private Methods
    var _privateMethod = function () {
       log("privateMethod: accessed only from within AppLaunch.Admin");
    }; // Last variable in a chain must always end with ; before the return {}

    function log() {
        if (window.console && window.console.log)
            window.console.log('[AppName] ' + Array.prototype.join.call(arguments, ' '));
    };

    return {
        init: function () {

            // Calling private
            _privateMethod();

            // Calling Public
            this.myPublicMethod();

            // Also Calling Public
            CompanyName.AppName.myPublicMethod();

            // Calling Other namespace's Public Method (when exists)
            CompanyName.OtherNamespace.externalPublicMethod(); 
        },

        // Public
        myPublicMethod: function() {
            log("myPublicMethod");
        },
        // In a View (MVC), I could have a page called myPage where I want to init
        // some particular functions. myPage can be called just like init. 
        myPage: function() { 
            _second();
            _third();
        }

    }
})(jQuery); 

// Initialize
jQuery().ready(function() {
    CompanyName.AppName.init()
    CompanyName.AppName.myPublicMethod();
});  

试图了解正在发生的事情(随意提供更正或更好的解释):

Company.AppName = (function ($) { ...

这里创建名称空间Company.AppName.我在里面设置($)所以我可以使用$而不会与任何其他可能使用$的库冲突.

})(jQuery); 

据我所知,方法和变量在这里返回到命名空间...})(); 通过在里面添加jQuery(),它会告诉它$表示jQuery.

初始化

我不确定这里的最佳做法是什么,但我会添加到目前为止我所知道的内容.

在js文件中初始化:

jQuery(function() { 
    AppLaunch.Admin.init();
});

从文件初始化:

<script type="text/javascript">
// Shorthand for jQuery(document).ready(function() { ... }

jQuery(function($) { 
    AppLaunch.Admin.init($('#someSelector'));     
});
</script>

Answer 1

有很多地方可以让您深入解释模块模式; jQuery对它的使用非常标准.

这只是众多模块模式解释中的一个.