Error handling:

- catch QuotaExceededError
- add generic error message to the spinner

client/src/app/app.module.ts

@@ -1,5 +1,5 @@
 import { HttpClientModule, HttpClientXsrfModule } from '@angular/common/http';
-import { APP_INITIALIZER, NgModule } from '@angular/core';
+import { APP_INITIALIZER, ErrorHandler, NgModule } from '@angular/core';
 import { BrowserModule } from '@angular/platform-browser';
 import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
 import { ServiceWorkerModule } from '@angular/service-worker';
@@ -11,6 +11,7 @@ import { AppRoutingModule } from './app-routing.module';
 import { AppComponent } from './app.component';
 import { CoreModule } from './core/core.module';
 import { environment } from '../environments/environment';
+import { ErrorService } from './core/core-services/error.service';
 import { httpInterceptorProviders } from './core/core-services/http-interceptors';
 import { LoginModule } from './site/login/login.module';
 import { OpenSlidesTranslateModule } from './core/translate/openslides-translate-module';
@@ -47,7 +48,8 @@ export function AppLoaderFactory(appLoadService: AppLoadService): () => Promise<
     ],
     providers: [
         { provide: APP_INITIALIZER, useFactory: AppLoaderFactory, deps: [AppLoadService], multi: true },
-        httpInterceptorProviders
+        httpInterceptorProviders,
+        { provide: ErrorHandler, useClass: ErrorService }
     ],
     bootstrap: [AppComponent]
 })

client/src/app/core/core-services/data-store.service.ts

@@ -5,6 +5,7 @@ import { Observable, Subject } from 'rxjs';
 import { BaseModel, ModelConstructor } from '../../shared/models/base/base-model';
 import { CollectionStringMapperService } from './collection-string-mapper.service';
 import { Deferred } from '../promises/deferred';
+import { OpenSlidesStatusService } from './openslides-status.service';
 import { RelationCacheService } from './relation-cache.service';
 import { StorageService } from './storage.service';
 
@@ -338,7 +339,8 @@ export class DataStoreService {
     public constructor(
         private storageService: StorageService,
         private modelMapper: CollectionStringMapperService,
-        private DSUpdateManager: DataStoreUpdateManagerService
+        private DSUpdateManager: DataStoreUpdateManagerService,
+        private statusService: OpenSlidesStatusService
     ) {}
 
     /**
@@ -662,8 +664,16 @@ export class DataStoreService {
      */
     public async flushToStorage(changeId: number): Promise<void> {
         this._maxChangeId = changeId;
+        try {
             await this.storageService.set(DataStoreService.cachePrefix + 'DS', this.jsonStore);
             await this.storageService.set(DataStoreService.cachePrefix + 'maxChangeId', changeId);
+        } catch (e) {
+            if (e?.name === 'QuotaExceededError') {
+                this.statusService.setTooLessLocalStorage();
+            } else {
+                throw e;
+            }
+        }
     }
 
     public print(): void {

client/src/app/core/core-services/error.service.ts

@@ -0,0 +1,36 @@
+import { ErrorHandler, Injectable } from '@angular/core';
+
+import { OpenSlidesStatusService } from './openslides-status.service';
+
+@Injectable({
+    providedIn: 'root'
+})
+export class ErrorService extends ErrorHandler {
+    // TODO: This service cannot be injected into other services since it is constructed twice.
+    public constructor(private statusService: OpenSlidesStatusService) {
+        super();
+    }
+
+    public handleError(error: any): void {
+        const errorInformation = {
+            error,
+            name: this.guessName(error)
+        };
+        this.statusService.currentError.next(errorInformation);
+        super.handleError(error);
+    }
+
+    private guessName(error: any): string | null {
+        if (!error) {
+            return;
+        }
+
+        if (error.rejection?.name) {
+            return error.rejection.name;
+        }
+
+        if (error.name) {
+            return error.name;
+        }
+    }
+}

client/src/app/core/core-services/openslides-status.service.ts

@@ -6,6 +6,11 @@ import { History } from 'app/shared/models/core/history';
 import { BannerDefinition, BannerService } from '../ui-services/banner.service';
 import { Deferred } from '../promises/deferred';
 
+export interface ErrorInformation {
+    error: any;
+    name?: string;
+}
+
 /**
  * Holds information about OpenSlides. This is not included into other services to
  * avoid circular dependencies.
@@ -18,10 +23,12 @@ export class OpenSlidesStatusService {
      * in History mode, saves the history point.
      */
     private history: History = null;
-    private bannerDefinition: BannerDefinition = {
+    private historyBanner: BannerDefinition = {
         type: 'history'
     };
 
+    private tooLessLocalStorage = false;
+
     /**
      * Returns, if OpenSlides is in the history mode.
      */
@@ -35,6 +42,8 @@ export class OpenSlidesStatusService {
 
     public isPrioritizedClient = false;
 
+    public readonly currentError = new BehaviorSubject<ErrorInformation | null>(null);
+
     private _stable = new Deferred();
     private _bootedSubject = new BehaviorSubject<boolean>(false);
 
@@ -63,7 +72,7 @@ export class OpenSlidesStatusService {
      */
     public enterHistoryMode(history: History): void {
         this.history = history;
-        this.banner.addBanner(this.bannerDefinition);
+        this.banner.addBanner(this.historyBanner);
     }
 
     /**
@@ -71,6 +80,13 @@ export class OpenSlidesStatusService {
      */
     public leaveHistoryMode(): void {
         this.history = null;
-        this.banner.removeBanner(this.bannerDefinition);
+        this.banner.removeBanner(this.historyBanner);
+    }
+
+    public setTooLessLocalStorage(): void {
+        if (!this.tooLessLocalStorage) {
+            this.tooLessLocalStorage = true;
+            this.banner.addBanner({ type: 'tooLessLocalStorage' });
+        }
     }
 }

client/src/app/core/ui-services/banner.service.ts

@@ -30,10 +30,7 @@ export class BannerService {
 
     public activeBanners: BehaviorSubject<BannerDefinition[]> = new BehaviorSubject<BannerDefinition[]>([]);
 
-    public constructor(/*translate: TranslateService, */ offlineBroadcastService: OfflineBroadcastService) {
-        /*translate.onLangChange.subscribe(() => {
-            this.offlineBannerDefinition.text = translate.instant(this.offlineBannerDefinition.text);
-        });*/
+    public constructor(offlineBroadcastService: OfflineBroadcastService) {
         offlineBroadcastService.isOfflineObservable.subscribe(offline => {
             if (offline) {
                 this.addBanner(this.offlineBannerDefinition);

client/src/app/shared/components/banner/banner.component.html

@@ -3,6 +3,7 @@
     class="banner"
     [ngClass]="[
         banner.type === 'history' ? 'history-mode-indicator' : '',
+        banner.type === 'tooLessLocalStorage' ? 'too-less-local-storage-indicator' : '',
         banner.class ? banner.class : '',
         banner.largerOnMobileView ? 'larger-on-mobile' : ''
     ]"
@@ -13,6 +14,10 @@
         <span>({{ getHistoryTimestamp() }})</span>
         <a (click)="timeTravel.resumeTime()">{{ 'Exit' | translate }}</a>
     </ng-container>
+    <ng-container *ngSwitchCase="'tooLessLocalStorage'">
+        <span>{{ "QuotaExceededError: The local storage's quota is too low" | translate }}</span>
+        <a href="https://support.openslides.com/help/de-de/7/57" target="_blank">{{ 'Click here for more information' | translate }}</a>
+    </ng-container>
     <ng-container *ngSwitchDefault>
         <a class="banner-link" [routerLink]="banner.link" [style.cursor]="banner.link ? 'pointer' : 'default'">
             <mat-icon>{{ banner.icon }}</mat-icon>

client/src/app/shared/components/banner/banner.component.scss

@@ -40,7 +40,8 @@
     }
 }
 
-.history-mode-indicator {
+.history-mode-indicator,
+.too-less-local-storage-indicator {
     background: repeating-linear-gradient(45deg, #ffee00, #ffee00 10px, #070600 10px, #000000 20px);
 
     span,

client/src/app/shared/components/global-spinner/global-spinner.component.html

@@ -2,7 +2,11 @@
     <div class="spinner-container">
         <div>
             <div class="spinner-component"></div>
-            <div class="spinner-text">{{ text }}</div>
+            <div *ngIf="!error" class="spinner-text">{{ text }}</div>
+            <div *ngIf="error" class="spinner-text">
+                {{ 'An error happened' | translate}}{{ error.name ? ': ' + error.name : ''}}.<br>
+                {{ 'Please contact your system administrator.' | translate }}
+            </div>
         </div>
     </div>
 </os-overlay>

client/src/app/shared/components/global-spinner/global-spinner.component.ts

@@ -4,6 +4,7 @@ import { ChangeDetectorRef, Component, OnDestroy, OnInit } from '@angular/core';
 import { TranslateService } from '@ngx-translate/core';
 import { Subscription } from 'rxjs';
 
+import { ErrorInformation, OpenSlidesStatusService } from 'app/core/core-services/openslides-status.service';
 import { OverlayService } from 'app/core/ui-services/overlay.service';
 
 /**
@@ -35,6 +36,8 @@ export class GlobalSpinnerComponent implements OnInit, OnDestroy {
      */
     private LOADING = this.translate.instant('Loading data. Please wait ...');
 
+    public error: ErrorInformation | null = null;
+
     /**
      * Constructor
      *
@@ -45,8 +48,14 @@ export class GlobalSpinnerComponent implements OnInit, OnDestroy {
     public constructor(
         private overlayService: OverlayService,
         protected translate: TranslateService,
-        private cd: ChangeDetectorRef
-    ) {}
+        private cd: ChangeDetectorRef,
+        private statusService: OpenSlidesStatusService
+    ) {
+        this.statusService.currentError.subscribe(error => {
+            this.error = error;
+            this.cd.markForCheck();
+        });
+    }
 
     /**
      * Init method