17

我创建了一个新的 Angular 项目并按照此处的说明设置 HMR: https ://github.com/angular/angular-cli/wiki/stories-configure-hmr

该项目包含主组件(父组件),它具有router-outlet并链接到 3 个延迟加载的子组件。

注意:我也在使用自定义RouteReuseStrategy,但据我测试它对 HMR 没有影响。

无论我要更改什么文件 - .html 或 .ts(父/子),整个应用程序都会重新加载。

我已经建立了一个基本的仓库,可以在这里找到: https ://github.com/ronfogel/demo-hmr

4

2 回答 2

8

这种行为是意料之中的,我将尝试解释发生了什么。

Angular 设置的热模块替换实际上只是以更通用的方式重新引导整个应用程序并支持多个应用程序根目录,但是如果您将抽象放在一边简单地删除app-root标签,再次添加它并再次引导AppModule,所以整个应用程序发生变化:

export const hmrBootstrap = (
  // webpack stuff
  module: any,
  // bootstrap is AppModule bootstrapper 
  bootstrap: () => Promise<NgModuleRef<any>>
) => {
  let ngModule: NgModuleRef<any>;
  module.hot.accept();
  // bootstraps AppModule ecery time a HMR is needed
  // sets ngModule equal to AppModule if successful (unnecessary)
  bootstrap().then(mod => (ngModule = mod));
  module.hot.dispose(() => {
    // next two lines get native element for all `app-root` tags
    // that exist in `index.html`
    const appRef: ApplicationRef = ngModule.injector.get(ApplicationRef);
    const elements = appRef.components.map(c => c.location.nativeElement);
    // I will share createNewHosts code below it's nothing fancy just
    // the simple add and delete i mentioned
    const makeVisible = createNewHosts(elements);
    //destroy the current AppModule and finalize deletion
    ngModule.destroy();
    makeVisible();
  });
};
于 2018-10-09T19:11:32.250 回答
6

这是我用于最新 Angular 的,工作得很好。你可以试一试...

// main.ts
import { bootloader, createInputTransfer, createNewHosts, removeNgStyles } 
    from '@angularclass/hmr/dist/helpers'; // For correct treeshaking

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

type HmrModule<S> = { appRef: ApplicationRef }
type HmrNgrxModule<S, A> = HmrModule<S> & { 
  store: { dispatch: (A) => any } & Observable<S>,
  actionCreator: (s: S) => A
}

const isNgrxModule = <S, A, M extends HmrNgrxModule<S, A>>
  (instance: HmrModule<S> | HmrNgrxModule<S, A>): instance is M =>
    !!((<M>instance).store && (<M>instance).actionCreator);

function processModule<S, A, M extends HmrModule<S> | HmrNgrxModule<S, A>>(ngModuleRef: NgModuleRef<M>) {

  const hot = module['hot'];
  if (hot) {

    hot['accept']();

    const instance = ngModuleRef.instance;
    const hmrStore = hot['data'];

    if (hmrStore) {
      hmrStore.rootState 
        && isNgrxModule(instance) 
        && instance.store.dispatch(instance.actionCreator(hmrStore.rootState));
      hmrStore.restoreInputValues && hmrStore.restoreInputValues();
      instance.appRef.tick();
      Object.keys(hmrStore).forEach(prop => delete hmrStore[prop]);
    }

    hot['dispose'](hmrStore => {
      isNgrxModule(instance) && instance.store.pipe(take(1)).subscribe(s => hmrStore.rootState = s);
      const cmpLocation = instance.appRef.components.map(cmp => cmp.location.nativeElement);
      const disposeOldHosts = createNewHosts(cmpLocation);
      hmrStore.restoreInputValues = createInputTransfer();
      removeNgStyles();
      ngModuleRef.destroy();
      disposeOldHosts();
    });
  }
  else {
    console.error('HMR is not enabled for webpack-dev-server!');
    console.log('Are you using the --hmr flag for ng serve?');
  }

  return ngModuleRef;
}

const bootstrap = () => platformBrowserDynamic().bootstrapModule(AppModule);
const hmrBootstrap = () => bootloader(() => bootstrap().then(processModule));

environment.hmr
  ? hmrBootstrap()
  : bootstrap();
// app.module.ts
@NgModule({ ... })
export class AppModule {
  constructor(public appRef: ApplicationRef) { ... }
}

HMR如果您喜欢这类东西,该设置也适用于 Ngrx 商店。不过,您可以省略 Ngrx 处理代码。

希望这有所帮助 :-)

于 2018-09-17T08:50:03.427 回答