JS模块化规范AMD之RequireJS

1.基本操作

1. 加载 JavaScript 文件（入口文件）

   RequireJS以一个相对于baseUrl的地址来加载所有的代码

   <script data-main="scripts/main.js" src="scripts/require.js"></script>
   

2. 相关配置

   requirejs.config({
   
       baseUrl: 'js/lib',
   
       paths: {
           app: '../app'
       }
   });
   
   requirejs(['jquery', 'canvas', 'app/sub'],
   function   ($,        canvas,   sub) {
       //jQuery, canvas and the app/sub module are all
       //loaded and can be used here now.
   });
   

2.模块相关

1. 简单的值对

   define({
   
       color: "black",
       size: "unisize"
   });
   

2. 没有任何依赖的函数式定义

   define(function () {
   
       return {
           color: "black",
           size: "unisize"
       }
   });
   

3. 存在依赖的函数式定义

   define(["./cart", "./inventory"], function(cart, inventory) {
           //return an object to define the "my/shirt" module.
           return {
               color: "blue",
               size: "large",
               addToCart: function() {
                   inventory.decrement(this);
                   cart.add(this);
               }
           }
       }
   );
   

4.将模块定义为一个函数

    define(["my/cart", "my/inventory"],
        function(cart, inventory) {

            return function(title) {
                return title ? (window.title = title) :
                       inventory.storeName + ' ' + cart.name;
            }
        }
    );

3.简单包装CommonJS来定义模块

define(function(require, exports, module) {
    var a = require('a'),
        b = require('b');

    //Return the module value
    return function () {};
    }
);

4. 定义一个命名模块(jquery中使用)

define("foo/title",
    ["my/cart", "my/inventory"],
    function(cart, inventory) {
        //Define foo/title object in here.
   }
);

jquery:

if ( typeof define === "function" && define.amd ) {
    define( "jquery", [], function() {
        return jQuery;
    } );
}

5.JSONP服务依赖

为了在RequireJS中使用JSON服务，须要将callback参数的值指定为"define"。这意味着你可将获取到的JSONP URL的值看成是一个模块定义。

下面是一个调用JSONP API端点的示例。该示例中，JSONP的callback参数为"callback"，因此"callback=define"告诉API将JSON响应包裹到一个"define()"中：

require(["http://example.com/api/data.json?callback=define"],
    function (data) {
        //The data object will be the API response for the
        //JSONP data call.
        console.log(data);
    }
);

仅支持返回值类型为JSON object的JSONP服务，其他返回类型如数组、字串、数字等都不能支持。

6.压缩合并

1. 常规压缩合并

   node r.js -o baseUrl=js name=main out=built.js
   

   有外部CDN的情况

   //表示paths.jquery不参与合并，压缩。这时生成的built.js
   node r.js -o baseUrl=js name=main out=built.js paths.jquery=empty:  也就不包含它了。
   

   合并成大文件，设置配置文件

   ({
       appDir: "./",
       baseUrl: "js",
       dir: "../r6-built",
       paths: {
           jquery: 'empty:'
       },
       modules: [
           {
               name: "page1"
           },
           {
               name: "page2"
           }
       ]
   })
   

   命令

   node r.js -o build.js
   

2. 合并压缩CSS

   node r.js -o cssIn=css/main.css out=css/built.css
   

   还可以使用optimizeCss参数设置来配置是否压缩及压缩选项。

   optimizeCss的取值有

   none  不压缩，仅合并
   
   standard  标准压缩 去换行、空格、注释
   
   standard.keepLines  除标准压缩外，保留换行
   
   standard.keepComments  除标准压缩外，保留注释
   
   standard.keepComments.keepLines  除标准压缩外，保留换行和注释
   

   示例：

   node r.js -o cssIn=css/main.css out=css/built.css optimizeCss=standard
   

   压缩后built.css整个为一行了。

*:first-child {
margin-top: 0 !important;
}

body>*:last-child {
margin-bottom: 0 !important;
}

/* BLOCKS
=============================================================================*/

p, blockquote, ul, ol, dl, table, pre {
margin: 15px 0;
}

/* HEADERS
=============================================================================*/

h1, h2, h3, h4, h5, h6 {
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
}

h1 tt, h1 code, h2 tt, h2 code, h3 tt, h3 code, h4 tt, h4 code, h5 tt, h5 code, h6 tt, h6 code {
font-size: inherit;
}

body>h2:first-child, body>h1:first-child, body>h1:first-child+h2, body>h3:first-child, body>h4:first-child, body>h5:first-child, body>h6:first-child {
margin-top: 0;
padding-top: 0;
}

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0;
}

h1+p, h2+p, h3+p, h4+p, h5+p, h6+p {
margin-top: 10px;
}

/* LINKS
=============================================================================*/

a {
color: #4183C4;
text-decoration: none;
}

a:hover {
text-decoration: underline;
}

/* LISTS
=============================================================================*/

ul, ol {
padding-left: 30px;
}

ul li > :first-child,
ol li > :first-child,
ul li ul:first-of-type,
ol li ol:first-of-type,
ul li ol:first-of-type,
ol li ul:first-of-type {
margin-top: 0px;
}

ul ul, ul ol, ol ol, ol ul {
margin-bottom: 0;
}

dl {
padding: 0;
}

dl dt {
font-size: 14px;
font-weight: bold;
font-style: italic;
padding: 0;
margin: 15px 0 5px;
}

dl dt:first-child {
padding: 0;
}

dl dt>:first-child {
margin-top: 0px;
}

dl dt>:last-child {
margin-bottom: 0px;
}

dl dd {
margin: 0 0 15px;
padding: 0 15px;
}

dl dd>:first-child {
margin-top: 0px;
}

dl dd>:last-child {
margin-bottom: 0px;
}

/* CODE
=============================================================================*/

pre, code, tt {
font-size: 12px;
font-family: Consolas, "Liberation Mono", Courier, monospace;
}

code, tt {
margin: 0 0px;
padding: 0px 0px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px;
}

pre>code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent;
}

pre {
background-color: #f8f8f8;
border: 1px solid #ccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px;
}

pre code, pre tt {
background-color: transparent;
border: none;
}

kbd {
-moz-border-bottom-colors: none;
-moz-border-left-colors: none;
-moz-border-right-colors: none;
-moz-border-top-colors: none;
background-color: #DDDDDD;
background-image: linear-gradient(#F1F1F1, #DDDDDD);
background-repeat: repeat-x;
border-color: #DDDDDD #CCCCCC #CCCCCC #DDDDDD;
border-image: none;
border-radius: 2px 2px 2px 2px;
border-style: solid;
border-width: 1px;
font-family: "Helvetica Neue",Helvetica,Arial,sans-serif;
line-height: 10px;
padding: 1px 4px;
}

/* QUOTES
=============================================================================*/

blockquote {
border-left: 4px solid #DDD;
padding: 0 15px;
color: #777;
}

blockquote>:first-child {
margin-top: 0px;
}

blockquote>:last-child {
margin-bottom: 0px;
}

/* HORIZONTAL RULES
=============================================================================*/

hr {
clear: both;
margin: 15px 0;
height: 0px;
overflow: hidden;
border: none;
background: transparent;
border-bottom: 4px solid #ddd;
padding: 0;
}

.postBody a:link, .postBody a:visited, .postBody a:active ,.postBody a,.postBody a:hover,{
text-decoration: none;
}
a:hover{
cursor: pointer;
}
/* IMAGES
=============================================================================*/

img {
max-width: 100%
}
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