🔥 Angular 2 Hot Module Replacement for Hot Module Reloading via @AngularClass
TypeScript
Latest commit ba628b5 Dec 14, 2016 @blackmiaool blackmiaool committed with gdi2290 fix: typo in readme (#41)

README.md

Angular 2 Fundamentals


Angular 2 Hot Module Replacement

Angular2-HMR Hot Module Reloading for Webpack 2 and Angular 2. All versions of Angular will work with this module

npm install @angularclass/hmr @angularclass/hmr-loader

Please see repository AngularClass/angular2-seed for a working example.
Also download AngularClass/angular2-hmr-loader

hmr-state-dom

main.browser.ts

import { removeNgStyles, createNewHosts, bootloader } from '@angularclass/hmr';

@NgModule({
  bootstrap: [ App ],
  declarations: [ App ],
  imports: [
    // Angular 2
    BrowserModule,
    FormsModule,
    HttpModule,
    RouterModule.forRoot([], {
      useHash: true
    }),
    // app
    appModule
    // vendors
  ],
  providers: []
})
class MainModule {
  constructor(public appRef: ApplicationRef) {}
  hmrOnInit(store) {
    if (!store || !store.state) return;
    console.log('HMR store', store);
    console.log('store.state.data:', store.state.data)
    // inject AppStore here and update it
    // this.AppStore.update(store.state)
    if ('restoreInputValues' in store) {
      store.restoreInputValues();
    }
    // change detection
    this.appRef.tick();
    delete store.state;
    delete store.restoreInputValues;
  }
  hmrOnDestroy(store) {
    var cmpLocation = this.appRef.components.map(cmp => cmp.location.nativeElement);
    // recreate elements
    store.disposeOldHosts = createNewHosts(cmpLocation)
    // inject your AppStore and grab state then set it on store
    // var appState = this.AppStore.get()
    store.state = {data: 'yolo'};
    // store.state = Object.assign({}, appState)
    // save input values
    store.restoreInputValues  = createInputTransfer();
    // remove styles
    removeNgStyles();
  }
  hmrAfterDestroy(store) {
    // display new elements
    store.disposeOldHosts()
    delete store.disposeOldHosts;
    // anything you need done the component is removed
  }
}

export function main() {
  return platformBrowserDynamic().bootstrapModule(MainModule);
}

// boot on document ready
bootloader(main);

bootloader is only needed to detect that the dom is ready before bootstraping otherwise bootstrap. This is needed because that dom is already ready during reloading.

Important Helpers

  • removeNgStyles: remove angular styles
  • createNewHosts and disposeOldHosts: recreate root elements for bootstrapping
  • bootloader: boot on document ready or boot if it's already ready
  • createInputTransfer and restoreInputValues: transfer input DOM state during replacement

Production

In production you only need bootloader which just does this:

export function bootloader(main) {
  if (document.readyState === 'complete') {
    main()
  } else {
    document.addEventListener('DOMContentLoaded', main);
  }
}

You would bootstrap your app the normal way, in production, after dom is ready. Also, in production, you should remove the loader:

        {
          test: /\.ts$/,
          loaders: [
            'awesome-typescript-loader',
          ].concat(prod ? [] : '@angularclass/hmr-loader')
        },

enjoy — AngularClass



AngularClass

AngularClass

Learn AngularJS, Angular 2, and Modern Web Development from the best. Looking for corporate Angular training, want to host us, or Angular consulting? patrick@angularclass.com