app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { NgModule, APP_INITIALIZER } from '@angular/core';
import { HttpClientModule } from '@angular/common/http';

import { AppComponent } from './app.component';
import { AppRoutingModule } from './app-routing.module';
import { CoreModule } from './core/core.module';
import { EditorialisationModule } from './editorialisation/editorialisation.module';
import { Angulartics2Module } from 'angulartics2';
import { UserModule } from './user/user.module';
import { UserService } from './user/services';
import { AppConfigService } from './core/services';

// Function used by APP_INITIALIZER before the app start: init user info / statut (expect a promise)
export function initUserService(authService: UserService) {
  return (): Promise<any> => {
    return new Promise((resolve, reject) => {
      authService.initializeService();
      resolve();
    });
  };
}

export function initAppConfig(appConfigService: AppConfigService) {
  return (): Promise<any> => {
    return new Promise((resolve, reject) => {
      appConfigService.load();
      resolve();
    });
  };
}

@NgModule({
  declarations: [
    AppComponent,
  ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    HttpClientModule,
    CoreModule,
    EditorialisationModule,
    UserModule,
    AppRoutingModule,
    Angulartics2Module.forRoot(),
  ],
  providers: [
    // The order is important as the InitUserService require the configuration of the app
    {
      provide: APP_INITIALIZER,
      useFactory: initAppConfig,
      deps: [AppConfigService],
      multi: true,
    },
    {
      provide: APP_INITIALIZER,
      useFactory: initUserService,
      deps: [UserService],
      multi: true,
    },
  ],
  bootstrap: [AppComponent],
})
export class AppModule { }