问道Angular——Angular5、6、7项目添加热更新(HMR)功能.md

使用hmr-cli

npm i -g hmr-cli

  初始化angular项目,命令行进入该目录

hmr init

  npm run hmr启动项目将附带hmr功能。

---

Angular6添加HMR

environments目录

environments.ts和environment.prod.ts增加hmr: false

export const environment = {
  hmr: false
};

复制environment新增environment.hmr.ts修改hmr:true

export const environment = {
  hmr: true
};

.angular.json文件

build的configurations中添加

"hmr": {
  "fileReplacements": [
    {
      "replace": "src/environments/environment.ts",
      "with": "src/environments/environment.hmr.ts"
    }
  ]
}

serve的configurations中添加

"hmr": {
  "hmr": true,
  "browserTarget": "my-app:build:hmr"
}

tsconfig.app.json的compilerOptions的types中添加

"types": ["node"]

package.json的scripts中添加

"hmr": "ng serve --configuration hmr --open"

安装依赖

npm install --save-dev @angularclass/hmr

src目录下创建hmr.ts

import { NgModuleRef, ApplicationRef } from '@angular/core';
import { createNewHosts } from '@angularclass/hmr';

export const hmrBootstrap = (module: any, bootstrap: () => Promise<NgModuleRef<any>>) => {
  let ngModule: NgModuleRef<any>;
  module.hot.accept();
  bootstrap().then(mod => ngModule = mod);
  module.hot.dispose(() => {
    const appRef: ApplicationRef = ngModule.injector.get(ApplicationRef);
    const elements = appRef.components.map(c => c.location.nativeElement);
    const makeVisible = createNewHosts(elements);
    ngModule.destroy();
    makeVisible();
  });
};

修改main.ts

import { enableProdMode } from '@angular/core';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';

import { AppModule } from './app/app.module';
import { environment } from './environments/environment';

import { hmrBootstrap } from './hmr';

if (environment.production) {
  enableProdMode();
}

const bootstrap = () => platformBrowserDynamic().bootstrapModule(AppModule);

if (environment.hmr) {
  if (module[ 'hot' ]) {
    hmrBootstrap(module, bootstrap);
  } else {
    console.error('HMR is not enabled for webpack-dev-server!');
    console.log('Are you using the --hmr flag for ng serve?');
  }
} else {
  bootstrap().catch(err => console.log(err));
}

Angular5添加HMR

environments目录

environments.ts和environment.prod.ts增加hmr: false

export const environment = {
  hmr: false
};

复制environment新增environment.hmr.ts修改hmr:true

export const environment = {
  hmr: true
};

.angular-cli.json的environments中添加

"hmr": "environments/environment.hmr.ts"

在package.json的scripts中增加

"hmr": "ng serve --hmr -e=hmr --open"

安装依赖

npm install --save-dev @angularclass/hmr

src目录下创建hmr.ts

import { NgModuleRef, ApplicationRef } from '@angular/core';
import { createNewHosts } from '@angularclass/hmr';

export const hmrBootstrap = (module: any, bootstrap: () => Promise<NgModuleRef<any>>) => {
  let ngModule: NgModuleRef<any>;
  module.hot.accept();
  bootstrap().then(mod => ngModule = mod);
  module.hot.dispose(() => {
    const appRef: ApplicationRef = ngModule.injector.get(ApplicationRef);
    const elements = appRef.components.map(c => c.location.nativeElement);
    const makeVisible = createNewHosts(elements);
    ngModule.destroy();
    makeVisible();
  });
};

修改main.ts

import { enableProdMode } from '@angular/core';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';

import { AppModule } from './app/app.module';
import { environment } from './environments/environment';

import { hmrBootstrap } from './hmr';

if (environment.production) {
  enableProdMode();
}

const bootstrap = () => platformBrowserDynamic().bootstrapModule(AppModule);

if (environment.hmr) {
  if (module[ 'hot' ]) {
    hmrBootstrap(module, bootstrap);
  } else {
    console.error('HMR is not enabled for webpack-dev-server!');
    console.log('Are you using the --hmr flag for ng serve?');
  }
} else {
  bootstrap().catch(err => console.log(err));
}