Angular2初探

　　Angular2是Google下一代MV*框架，用于构建复杂浏览器应用。Angular2给WEB或移动Apps带来了一揽子解决方案，从模板渲染到数据绑定，从Http服务到表单处理等等，总之，你想要的，Angular2基本上都已封装好了。
　　万事始于Hello World，不论Angular2怎么牛，咱们先得把官方的例子跑起来再说。这里使用基于webpack创建Angular应用。

环境准备
　　node v5.x.x
　　npm v3.x.x
step1：创建并配置本项目
创建项目目录：

mkdir angular2Demo
cd angular2Demo

创建配置文件
典型的 Angular 项目需要一系列配置文件
package.json 用来标记出本项目所需的 npm 依赖包。
tsconfig.json 定义了 TypeScript 编译器如何从项目源文件生成 JavaScript 代码。
typings.json 为那些 TypeScript 编译器无法识别的库提供了额外的定义文件。
webpack.config.js为构建Angular应用所进行的一系列webpack配置。

package.json

{
  "name": "angular2demo","version": "1.0.0","description": "Angular 2 demo.","main": "index.js","scripts": { "start": "webpack-dev-server --inline --progress --port 8080","test": "karma start","build": "rimraf dist && webpack --config config/webpack.prod.js --progress --profile --bail","postinstall": "typings install" },"dependencies": { "@angular/common": "2.0.0","@angular/compiler": "2.0.0","@angular/core": "2.0.0","@angular/forms": "2.0.0","@angular/http": "2.0.0","@angular/platform-browser": "2.0.0","@angular/platform-browser-dynamic": "2.0.0","@angular/router": "3.0.0","core-js": "^2.4.1","rxjs": "5.0.0-beta.12","zone.js": "^0.6.23" },"devDependencies": { "angular2-template-loader": "^0.4.0","awesome-typescript-loader": "^2.2.4","css-loader": "^0.23.1","extract-text-webpack-plugin": "^1.0.1","file-loader": "^0.8.5","html-loader": "^0.4.3","html-webpack-plugin": "^2.15.0","jasmine-core": "^2.4.1","karma": "^1.2.0","karma-jasmine": "^1.0.2","karma-phantomjs-launcher": "^1.0.2","karma-sourcemap-loader": "^0.3.7","karma-webpack": "^1.8.0","null-loader": "^0.1.1","phantomjs-prebuilt": "^2.1.7","raw-loader": "^0.5.1","rimraf": "^2.5.2","style-loader": "^0.13.1","typescript": "^2.0.2","typings": "^1.3.2","webpack": "^1.13.0","webpack-dev-server": "^1.14.1","webpack-merge": "^0.14.0" },"repository": { "type": "git","url": "git+https://github.com/HalZhan/angular2Demo.git" },"author": "halzhan","license": "MIT","bugs": { "url": "https://github.com/HalZhan/angular2Demo/issues" },"homepage": "https://github.com/HalZhan/angular2Demo#readme" }

tsconfig.json

{
  "compilerOptions": { "target": "es5","module": "commonjs","moduleResolution": "node","sourceMap": true,"emitDecoratorMetadata": true,"experimentalDecorators": true,"removeComments": false,"noImplicitAny": true,"suppressImplicitAnyIndexErrors": true } }

typings.json

{
  "globalDependencies": { "core-js": "registry:dt/core-js#0.0.0+20160725163759","jasmine": "registry:dt/jasmine#2.2.0+20160621224255","node": "registry:dt/node#6.0.0+20160909174046" } }

webpack.config.js

module.exports = require('./config/webpack.dev.js'); // 待补充

karma.conf.js

module.exports = require('./config/karma.conf.js'); // 待补充

下面我们继续完善配置文件。
公共配置
　　我们可以为开发、产品和测试环境定义分别各自的配置文件。 但三者总会有一些公共配置。 于是我们把那些公共的配置收集到一个名叫 webpack.common.js 的独立文件中。

config/webpack.common.js

var webpack = require('webpack');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var ExtractTextPlugin = require('extract-text-webpack-plugin');
var helpers = require('./helpers');

module.exports = {
  entry: {
    'polyfills': './src/polyfills.ts',// 运行Angular时所需的一些标准js
    'vendor': './src/vendor.ts',// Angular、Lodash、bootstrap.css......
    'app': './src/main.ts' // 应用代码
  },resolve: {
    extensions: ['','.js','.ts'] // 加载的文件类型(明确的扩展名、.js、.ts)
  },module: {
    loaders: [
      {
        test: /\.ts$/,loaders: ['awesome-typescript-loader','angular2-template-loader' // 用于加载 Angular 组件的模板和样式
        ]
      },// ts - 将typescript代码转译成es5的加载器，由tsconfig.json文件指导
      {
        test: /\.html$/,loader: 'html' // 为组件模板准备的加载器
      },{
        test: /\.(png|jpe?g|gif|svg|woff|woff2|ttf|eot|ico)$/,loader: 'file?name=assets/[name].[hash].[ext]' // 图片和字体文件也能被打包
      },{
        test: /\.css$/,exclude: helpers.root('src','app'),loader: ExtractTextPlugin.extract('style','css?sourceMap')
      },// 模式匹配应用级样式
      {
        test: /\.css$/,include: helpers.root('src',loader: 'raw'
      } // 模式匹配组件局部样式 ( 在组件元数据的 styleUrls 属性中指定的那些 ) 
    ]
  },plugins: [
    new webpack.optimize.CommonsChunkPlugin({
      name: ['app','vendor','polyfills']
    }),// 提取公共代码

    new HtmlWebpackPlugin({
      template: 'src/index.html'
    }) // 自动向目标.html文件注入script和link标签
  ]
};

config/helpers.js

var path = require('path');
var _root = path.resolve(__dirname,'..');
function root(args) {
  args = Array.prototype.slice.call(arguments,0);
  return path.join.apply(path,[_root].concat(args));
}
exports.root = root;

开发环境配置
config/webpack.dev.js

var webpackMerge = require('webpack-merge');
var ExtractTextPlugin = require('extract-text-webpack-plugin');
var commonConfig = require('./webpack.common.js');
var helpers = require('./helpers');

module.exports = webpackMerge(commonConfig,{
  devtool: 'cheap-module-eval-source-map',output: {
    path: helpers.root('dist'),publicPath: 'http://localhost:8080/',filename: '[name].js',chunkFilename: '[id].chunk.js'
  },plugins: [
    new ExtractTextPlugin('[name].css')
  ],devServer: {
    historyApiFallback: true,stats: 'minimal'
  }
});

产品环境配置
config/webpack.prod.js

var webpack = require('webpack');
var webpackMerge = require('webpack-merge');
var ExtractTextPlugin = require('extract-text-webpack-plugin');
var commonConfig = require('./webpack.common.js');
var helpers = require('./helpers');

const ENV = process.env.NODE_ENV = process.env.ENV = 'production';

module.exports = webpackMerge(commonConfig,{
  devtool: 'source-map',output: {
    path: helpers.root('dist'),publicPath: '/',filename: '[name].[hash].js',chunkFilename: '[id].[hash].chunk.js'
  },htmlLoader: {
    minimize: false // workaround for ng2
  },plugins: [
    new webpack.NoErrorsPlugin(),// 如果出现任何错误，就终止构建
    new webpack.optimize.DedupePlugin(),// 检测完全相同 ( 以及几乎完全相同 ) 的文件，并把它们从输出中移除
    new webpack.optimize.UglifyJsPlugin({ // https://github.com/angular/angular/issues/10618
                                          // 最小化 (minify) 生成的包
      mangle: {
        keep_fnames: true
      }
    }),new ExtractTextPlugin('[name].[hash].css'),// 把内嵌的 css 抽取成外部文件，并为其文件名添加“缓存无效哈希”
    new webpack.DefinePlugin({ // 用来定义环境变量，以便我们在自己的程序中引用它
      'process.env': {
        'ENV': JSON.stringify(ENV)
      }
    })
  ]
});

(可选)测试环境配置
config/webpack.test.js

var helpers = require('./helpers');

module.exports = {
  devtool: 'inline-source-map',resolve: {
    extensions: ['','.ts','.js']
  },module: {
    loaders: [
      {
        test: /\.ts$/,loaders: ['awesome-typescript-loader','angular2-template-loader']
      },{
        test: /\.html$/,loader: 'html'

      },{
        test: /\.(png|jpe?g|gif|svg|woff|woff2|ttf|eot|ico)$/,loader: 'null'
      },{
        test: /\.css$/,exclude: helpers.root('src',include: helpers.root('src',loader: 'raw'
      }
    ]
  }
}

(可选)Karma单元测试配置
config/karma.conf.js

var webpackConfig = require('./webpack.test');

module.exports = function (config) {
  var _config = {
    basePath: '',frameworks: ['jasmine'],files: [
      {pattern: './config/karma-test-shim.js',watched: false}
    ],preprocessors: {
      './config/karma-test-shim.js': ['webpack','sourcemap']
    },webpack: webpackConfig,webpackMiddleware: {
      stats: 'errors-only'
    },webpackServer: {
      noInfo: true
    },reporters: ['progress'],port: 9876,colors: true,logLevel: config.LOG_INFO,autoWatch: false,browsers: ['PhantomJS'],singleRun: true
  };

  config.set(_config);
};

config/karma-test-shim.js
　　告诉 Karma 哪些文件需要预加载，首要的是：带有“测试版提供商”的 Angular 测试框架是每个应用都希望预加载的。

Error.stackTraceLimit = Infinity;

require('core-js/es6');
require('core-js/es7/reflect');

require('zone.js/dist/zone');
require('zone.js/dist/long-stack-trace-zone');
require('zone.js/dist/proxy');
require('zone.js/dist/sync-test');
require('zone.js/dist/jasmine-patch');
require('zone.js/dist/async-test');
require('zone.js/dist/fake-async-test');

var appContext = require.context('../src',true,/\.spec\.ts/);

appContext.keys().forEach(appContext);

var testing = require('@angular/core/testing');
var browser = require('@angular/platform-browser-dynamic/testing');

testing.Testbed.initTestEnvironment(browser.browserDynamicTestingModule,browser.platformbrowserDynamicTesting());

step2：编写源码
src/index.html

<!DOCTYPE html>
<html>
  <head>
    <base href="/">
    <title>Angular With Webpack</title>
    <Meta charset="UTF-8">
    <Meta name="viewport" content="width=device-width,initial-scale=1">
  </head>
  <body>
    <my-app>Loading...</my-app>
  </body>
</html>

src/main.ts

import { platformbrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app/app.module';
if (process.env.ENV === 'production') {
  enableProdMode();
}
platformbrowserDynamic().bootstrapModule(AppModule);

public/css/styles.css

body { background: #0147A7; color: #fff; }

src/app/app.component.ts

import { Component } from '@angular/core';
import '../../public/css/styles.css';
@Component({
  selector: 'my-app',templateUrl: './app.component.html',styleUrls: ['./app.component.css']
})
export class AppComponent { }

src/app/app.component.html
这里需要用到Angular Logo，下载后放入”public/images/”目录下。

<main>
  <h1>Hello from Angular App with Webpack</h1>
  <img src="../../public/images/angular.png">
</main>

src/app/app.component.css

main { padding: 1em; font-family: Arial,Helvetica,sans-serif; text-align: center; margin-top: 50px; display: block; }

(用于单元测试，可选)src/app/app.component.spec.ts

import { Testbed } from '@angular/core/testing';
import { AppComponent } from './app.component';
describe('App',() => { beforeEach(() => { Testbed.configureTestingModule({ declarations: [AppComponent]}); }); it ('should work',() => { let fixture = Testbed.createComponent(AppComponent); expect(fixture.componentInstance instanceof AppComponent).toBe(true,'should create AppComponent'); }); });

src/app/app.module.ts

import { NgModule } from '@angular/core';
import { browserModule }  from '@angular/platform-browser';
import { AppComponent } from './app.component';
@NgModule({
  imports: [
    browserModule
  ],declarations: [
    AppComponent
  ],bootstrap: [ AppComponent ]
})
export class AppModule { }

src/vendor.ts

// Angular
import '@angular/platform-browser';
import '@angular/platform-browser-dynamic';
import '@angular/core';
import '@angular/common';
import '@angular/http';
import '@angular/router';
// RxJS
import 'rxjs';
// Other vendors for example jQuery,Lodash or Bootstrap
// You can import js,ts,css,sass,...

src/polyfills.ts

import 'core-js/es6';
import 'core-js/es7/reflect';
require('zone.js/dist/zone');
if (process.env.ENV === 'production') {
  // Production
} else {
  // Development
  Error['stackTraceLimit'] = Infinity;
  require('zone.js/dist/long-stack-trace-zone');
}

step3：编译运行
1. 在项目根目录下，执行

webpack --progress --colors

(–progress –colors是为了查看进度，可以不用加)
2. 全局安装webpack-dev-server

npm install -g webpack-dev-server --verbose

(–verbose可以显示安装详细信息，可以不用加上)
3. 启动webpack server

webpack-dev-server --content-base dist/

(设置静态文件访问路径)

step4：查看结果
访问localhost:8080，如果一切顺利，我们能够看到最终的结果：

样例源码已托管至github，如有兴趣可自行clone

git clone https://github.com/HalZhan/angular2Demo.git