Trigger an action at app init

medium-ngrx-indexeddb-AppInitAction.ts

@NgModule({
...
})
export class AppModule {
  constructor(applicationInitStatus: ApplicationInitStatus,
              store: Store<AppState>) {
    // dispatch the app init action when all stores have add a chance to rehydrate from indexedDb
    applicationInitStatus.donePromise.then(() => store.dispatch(new AppInitAction()))
  }
}