Detailed explanation of examples of using third-party library Immutable.js in WeChat applet-PHP开发-php.cn

Detailed explanation of examples of using third-party library Immutable.js in WeChat applet

高洛峰

Release： 2016-12-29 16:35:09

Original

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前言

Immutable JS 提供一个惰性 Sequence，允许高效的队列方法链，类似 map 和 filter ，不用创建中间代表。immutable 通过惰性队列和哈希映射提供 Sequence, Range, Repeat, Map, OrderedMap, Set 和一个稀疏 Vector。

微信小程序无法直接使用require( 'immutable.js' )进行调用,需要对下载的Immutable代码进行修改,才能使用。

原因分析

Immutable使用了UMD模块化规范

(function (global, factory) {
 typeof exports === &#39;object&#39; && typeof module !== &#39;undefined&#39; ? module.exports = factory() :
 typeof define === &#39;function&#39; && define.amd ? define(factory) :
 (global.Immutable = factory());
}(this, function () { &#39;use strict&#39;;var SLICE$0 = Array.prototype.slice;
 
....
 
}));

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UMD的实现很简单，先判断是否支持Node.js（CommonJS）模块规范，存在则使用Node.js（CommonJS）方式加载模块。再判断是否支持AMD，存在则使用AMD方式加载模块。前两个都不存在，则将模块公开到全局。

exports、module必须都有定义，才能以CommonJS加载模块。通过测试，微信小程序运行环境exports、module并没有定义。

解决方法

修改Immutable代码，注释原有模块导出语句，使用module.exports = factory() 强制导出

(function(global, factory) {
 /*
 typeof exports === &#39;object&#39; && typeof module !== &#39;undefined&#39; ? module.exports = factory() :
 typeof define === &#39;function&#39; && define.amd ? define(factory) :
 (global.Immutable = factory());
 */
 
 module.exports = factory();
 
}(this, function() {

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使用Immutable.js

//index.js
 
var Immutable = require( &#39;../../libs/immutable/immutable.modified.js&#39; );
 
//获取应用实例
var app = getApp();
 
Page( {
 
 onLoad: function() {
 //console.log(&#39;onLoad&#39;);
 var that = this;
 
 var lines = [];
 
 lines.push( "var map1 = Immutable.Map({a:1, b:2, c:3});" );
 var map1 = Immutable.Map({a:1, b:2, c:3});
 lines.push( "var map2 = map1.set(&#39;b&#39;, 50);" );
 var map2 = map1.set(&#39;b&#39;, 50);
 lines.push( "map1.get(&#39;b&#39;);" );
 lines.push(map1.get(&#39;b&#39;));
 lines.push( "map2.get(&#39;b&#39;);" );
 lines.push(map2.get(&#39;b&#39;)); 
 
 this.setData( {
  text: lines.join( &#39;\n&#39; )
 })
 }
})

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Detailed explanation of examples of using third-party library Immutable.js in WeChat applet