93219: Move APP_INITIALIZER logic into InitService

src/app/app.module.ts

@@ -7,13 +7,9 @@ import { BrowserModule } from '@angular/platform-browser';
 import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
 import { EffectsModule } from '@ngrx/effects';
 import { RouterStateSerializer, StoreRouterConnectingModule } from '@ngrx/router-store';
-import { MetaReducer, Store, StoreModule, USER_PROVIDED_META_REDUCERS } from '@ngrx/store';
+import { MetaReducer, StoreModule, USER_PROVIDED_META_REDUCERS } from '@ngrx/store';
 import { StoreDevtoolsModule } from '@ngrx/store-devtools';
-import {
-  DYNAMIC_ERROR_MESSAGES_MATCHER,
-  DYNAMIC_MATCHER_PROVIDERS,
-  DynamicErrorMessagesMatcher
-} from '@ng-dynamic-forms/core';
+import { DYNAMIC_ERROR_MESSAGES_MATCHER, DYNAMIC_MATCHER_PROVIDERS, DynamicErrorMessagesMatcher } from '@ng-dynamic-forms/core';
 import { TranslateModule } from '@ngx-translate/core';
 import { ScrollToModule } from '@nicky-lenaers/ngx-scroll-to';
 import { AppRoutingModule } from './app-routing.module';
@@ -21,7 +17,6 @@ import { AppComponent } from './app.component';
 import { appEffects } from './app.effects';
 import { appMetaReducers, debugMetaReducers } from './app.metareducers';
 import { appReducers, AppState, storeModuleConfig } from './app.reducer';
-import { CheckAuthenticationTokenAction } from './core/auth/auth.actions';
 import { CoreModule } from './core/core.module';
 import { ClientCookieService } from './core/services/client-cookie.service';
 import { NavbarModule } from './navbar/navbar.module';
@@ -36,6 +31,7 @@ import { EagerThemesModule } from '../themes/eager-themes.module';
 
 import { APP_CONFIG, AppConfig } from '../config/app-config.interface';
 import { RootModule } from './root.module';
+import { InitService } from './init.service';
 
 export function getConfig() {
   return environment;
@@ -82,6 +78,12 @@ IMPORTS.push(
 );
 
 const PROVIDERS = [
+  {
+    provide: APP_INITIALIZER,
+    useFactory: (initService: InitService) => initService.init(),
+    deps: [ InitService ],
+    multi: true,
+  },
   {
     provide: APP_CONFIG,
     useFactory: getConfig
@@ -101,15 +103,6 @@ const PROVIDERS = [
     useClass: DSpaceRouterStateSerializer
   },
   ClientCookieService,
-  // Check the authentication token when the app initializes
-  {
-    provide: APP_INITIALIZER,
-    useFactory: (store: Store<AppState>,) => {
-      return () => store.dispatch(new CheckAuthenticationTokenAction());
-    },
-    deps: [Store],
-    multi: true
-  },
   // register AuthInterceptor as HttpInterceptor
   {
     provide: HTTP_INTERCEPTORS,

src/app/init.service.ts

@@ -0,0 +1,63 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { Store } from '@ngrx/store';
+import { AppState } from './app.reducer';
+import { CheckAuthenticationTokenAction } from './core/auth/auth.actions';
+import { CorrelationIdService } from './correlation-id/correlation-id.service';
+import { DSpaceTransferState } from '../modules/transfer-state/dspace-transfer-state.service';
+
+/**
+ * Performs the initialization of the app.
+ *
+ * Should have distinct extensions for server & browser for the specifics.
+ * Should be provided in AppModule as follows
+ * ```
+ * {
+ *   provide: APP_INITIALIZER
+ *   useFactory: (initService: InitService) => initService.init(),
+ *   deps: [ InitService ],
+ *   multi: true,
+ * }
+ * ```
+ *
+ * In order to be injected in the common APP_INITIALIZER,
+ * concrete subclasses should be provided in their respective app modules as
+ * ```
+ * { provide: InitService, useClass: SpecificInitService }
+ * ```
+ */
+export abstract class InitService {
+  protected constructor(
+    protected store: Store<AppState>,
+    protected correlationIdService: CorrelationIdService,
+    protected dspaceTransferState: DSpaceTransferState,
+  ) {
+  }
+
+  /**
+   * Main initialization method, to be used as the APP_INITIALIZER factory.
+   *
+   * Note that the body of this method and the callback it returns are called
+   * at different times.
+   * This is important to take into account when other providers depend on the
+   * initialization logic (e.g. APP_BASE_HREF)
+   */
+  abstract init(): () => Promise<boolean>;
+
+  protected checkAuthenticationToken(): void {
+    this.store.dispatch(new CheckAuthenticationTokenAction());
+  }
+
+  protected initCorrelationId(): void {
+    this.correlationIdService.initCorrelationId();
+  }
+
+  protected async transferAppState(): Promise<unknown> {
+    return this.dspaceTransferState.transfer();
+  }
+}

src/modules/app/browser-app.module.ts

@@ -1,5 +1,5 @@
 import { HttpClient, HttpClientModule } from '@angular/common/http';
-import { APP_INITIALIZER, NgModule } from '@angular/core';
+import { NgModule } from '@angular/core';
 import { BrowserModule, makeStateKey, TransferState } from '@angular/platform-browser';
 import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
 import { REQUEST } from '@nguniversal/express-engine/tokens';
@@ -13,7 +13,6 @@ import { AppComponent } from '../../app/app.component';
 
 import { AppModule } from '../../app/app.module';
 import { DSpaceBrowserTransferStateModule } from '../transfer-state/dspace-browser-transfer-state.module';
-import { DSpaceTransferState } from '../transfer-state/dspace-transfer-state.service';
 import { ClientCookieService } from '../../app/core/services/client-cookie.service';
 import { CookieService } from '../../app/core/services/cookie.service';
 import { AuthService } from '../../app/core/auth/auth.service';
@@ -23,21 +22,13 @@ import { StatisticsModule } from '../../app/statistics/statistics.module';
 import { BrowserKlaroService } from '../../app/shared/cookies/browser-klaro.service';
 import { KlaroService } from '../../app/shared/cookies/klaro.service';
 import { HardRedirectService } from '../../app/core/services/hard-redirect.service';
-import {
-  BrowserHardRedirectService,
-  locationProvider,
-  LocationToken
-} from '../../app/core/services/browser-hard-redirect.service';
+import { BrowserHardRedirectService, locationProvider, LocationToken } from '../../app/core/services/browser-hard-redirect.service';
 import { LocaleService } from '../../app/core/locale/locale.service';
 import { GoogleAnalyticsService } from '../../app/statistics/google-analytics.service';
 import { AuthRequestService } from '../../app/core/auth/auth-request.service';
 import { BrowserAuthRequestService } from '../../app/core/auth/browser-auth-request.service';
-import { AppConfig, APP_CONFIG_STATE } from '../../config/app-config.interface';
-import { DefaultAppConfig } from '../../config/default-app-config';
-import { extendEnvironmentWithAppConfig } from '../../config/config.util';
-import { CorrelationIdService } from '../../app/correlation-id/correlation-id.service';
-
-import { environment } from '../../environments/environment';
+import { InitService } from 'src/app/init.service';
+import { BrowserInitService } from './browser-init.service';
 
 export const REQ_KEY = makeStateKey<string>('req');
 
@@ -73,25 +64,8 @@ export function getRequest(transferState: TransferState): any {
   ],
   providers: [
     {
-      provide: APP_INITIALIZER,
-      useFactory: (
-        transferState: TransferState,
-        dspaceTransferState: DSpaceTransferState,
-        correlationIdService: CorrelationIdService
-      ) => {
-        if (transferState.hasKey<AppConfig>(APP_CONFIG_STATE)) {
-          const appConfig = transferState.get<AppConfig>(APP_CONFIG_STATE, new DefaultAppConfig());
-          // extend environment with app config for browser
-          extendEnvironmentWithAppConfig(environment, appConfig);
-        }
-        return () =>
-          dspaceTransferState.transfer().then((b: boolean) => {
-            correlationIdService.initCorrelationId();
-            return b;
-          });
-      },
-      deps: [TransferState, DSpaceTransferState, CorrelationIdService],
-      multi: true
+      provide: InitService,
+      useClass: BrowserInitService,
     },
     {
       provide: REQUEST,

src/modules/app/browser-init.service.ts

@@ -0,0 +1,54 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { InitService } from '../../app/init.service';
+import { Store } from '@ngrx/store';
+import { AppState } from '../../app/app.reducer';
+import { DSpaceTransferState } from '../transfer-state/dspace-transfer-state.service';
+import { TransferState } from '@angular/platform-browser';
+import { APP_CONFIG_STATE, AppConfig } from '../../config/app-config.interface';
+import { DefaultAppConfig } from '../../config/default-app-config';
+import { extendEnvironmentWithAppConfig } from '../../config/config.util';
+import { environment } from '../../environments/environment';
+import { CorrelationIdService } from '../../app/correlation-id/correlation-id.service';
+import { Injectable } from '@angular/core';
+
+/**
+ * Performs client-side initialization.
+ */
+@Injectable()
+export class BrowserInitService extends InitService {
+  constructor(
+    protected store: Store<AppState>,
+    protected correlationIdService: CorrelationIdService,
+    protected transferState: TransferState,
+    protected dspaceTransferState: DSpaceTransferState,
+  ) {
+    super(store, correlationIdService, dspaceTransferState);
+  }
+
+  public init(): () => Promise<boolean> {
+    // this method must be called before the callback because APP_BASE_HREF depends on it
+    this.loadAppConfigFromSSR();
+
+    return async () => {
+      await this.transferAppState();
+      this.checkAuthenticationToken();
+      this.initCorrelationId();
+
+      return true;
+    };
+  }
+
+  private loadAppConfigFromSSR(): void {
+    if (this.transferState.hasKey<AppConfig>(APP_CONFIG_STATE)) {
+      const appConfig = this.transferState.get<AppConfig>(APP_CONFIG_STATE, new DefaultAppConfig());
+      // extend environment with app config for browser
+      extendEnvironmentWithAppConfig(environment, appConfig);
+    }
+  }
+}

src/modules/app/server-app.module.ts

@@ -1,9 +1,8 @@
 import { HTTP_INTERCEPTORS } from '@angular/common/http';
-import { APP_INITIALIZER, NgModule } from '@angular/core';
+import { NgModule } from '@angular/core';
 import { BrowserModule, TransferState } from '@angular/platform-browser';
 import { NoopAnimationsModule } from '@angular/platform-browser/animations';
 import { ServerModule } from '@angular/platform-server';
-import { RouterModule } from '@angular/router';
 
 import { TranslateLoader, TranslateModule } from '@ngx-translate/core';
 
@@ -14,7 +13,6 @@ import { AppComponent } from '../../app/app.component';
 
 import { AppModule } from '../../app/app.module';
 import { DSpaceServerTransferStateModule } from '../transfer-state/dspace-server-transfer-state.module';
-import { DSpaceTransferState } from '../transfer-state/dspace-transfer-state.service';
 import { TranslateServerLoader } from '../../ngx-translate-loaders/translate-server.loader';
 import { CookieService } from '../../app/core/services/cookie.service';
 import { ServerCookieService } from '../../app/core/services/server-cookie.service';
@@ -32,10 +30,8 @@ import { ServerHardRedirectService } from '../../app/core/services/server-hard-r
 import { Angulartics2Mock } from '../../app/shared/mocks/angulartics2.service.mock';
 import { AuthRequestService } from '../../app/core/auth/auth-request.service';
 import { ServerAuthRequestService } from '../../app/core/auth/server-auth-request.service';
-import { CorrelationIdService } from '../../app/correlation-id/correlation-id.service';
-import { AppConfig, APP_CONFIG_STATE } from '../../config/app-config.interface';
-
-import { environment } from '../../environments/environment';
+import { InitService } from '../../app/init.service';
+import { ServerInitService } from './server-init.service';
 
 export function createTranslateLoader(transferState: TransferState) {
   return new TranslateServerLoader(transferState, 'dist/server/assets/i18n/', '.json5');
@@ -60,21 +56,9 @@ export function createTranslateLoader(transferState: TransferState) {
     AppModule
   ],
   providers: [
-    // Initialize app config and extend environment
     {
-      provide: APP_INITIALIZER,
-      useFactory: (
-        transferState: TransferState,
-        dspaceTransferState: DSpaceTransferState,
-        correlationIdService: CorrelationIdService,
-      ) => {
-        transferState.set<AppConfig>(APP_CONFIG_STATE, environment as AppConfig);
-        dspaceTransferState.transfer();
-        correlationIdService.initCorrelationId();
-        return () => true;
-      },
-      deps: [TransferState, DSpaceTransferState, CorrelationIdService],
-      multi: true
+      provide: InitService,
+      useClass: ServerInitService,
     },
     {
       provide: Angulartics2,

src/modules/app/server-init.service.ts

@@ -0,0 +1,46 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { InitService } from '../../app/init.service';
+import { Store } from '@ngrx/store';
+import { AppState } from '../../app/app.reducer';
+import { TransferState } from '@angular/platform-browser';
+import { DSpaceTransferState } from '../transfer-state/dspace-transfer-state.service';
+import { CorrelationIdService } from '../../app/correlation-id/correlation-id.service';
+import { APP_CONFIG_STATE, AppConfig } from '../../config/app-config.interface';
+import { environment } from '../../environments/environment';
+import { Injectable } from '@angular/core';
+
+/**
+ * Performs server-side initialization.
+ */
+@Injectable()
+export class ServerInitService extends InitService {
+  constructor(
+    protected store: Store<AppState>,
+    protected correlationIdService: CorrelationIdService,
+    protected transferState: TransferState,
+    protected dspaceTransferState: DSpaceTransferState,
+  ) {
+    super(store, correlationIdService, dspaceTransferState);
+  }
+
+  public init(): () => Promise<boolean> {
+    return async () => {
+      this.checkAuthenticationToken();
+      this.saveAppConfigForCSR();
+      this.transferAppState();  // todo: SSR breaks if we await this (why?)
+      this.initCorrelationId();
+
+      return true;
+    };
+  }
+
+  private saveAppConfigForCSR(): void {
+    this.transferState.set<AppConfig>(APP_CONFIG_STATE, environment as AppConfig);
+  }
+}