Singleton DS, inject things into it.

client/src/app/core/rootInjector.ts

@@ -0,0 +1,6 @@
+import { Injector } from '@angular/core';
+
+export class RootInjector {
+    constructor() {}
+    public static injector: Injector;
+}

client/src/app/core/services/cache.service.spec.ts

@@ -0,0 +1,15 @@
+import { TestBed, inject } from '@angular/core/testing';
+
+import { CacheService } from './cache.service';
+
+describe('WebsocketService', () => {
+    beforeEach(() => {
+        TestBed.configureTestingModule({
+            providers: [CacheService]
+        });
+    });
+
+    it('should be created', inject([CacheService], (service: CacheService) => {
+        expect(service).toBeTruthy();
+    }));
+});

client/src/app/core/services/cache.service.ts

@@ -0,0 +1,21 @@
+import { Injectable } from '@angular/core';
+
+/**
+ * Handles all incoming and outgoing notify messages via {@link WebsocketService}.
+ */
+@Injectable({
+    providedIn: 'root'
+})
+export class CacheService {
+    /**
+     * Constructor to create the NotifyService. Registers itself to the WebsocketService.
+     * @param websocketService
+     */
+    constructor() {
+        console.log('Cache constructor');
+    }
+
+    public test() {
+        console.log('hi');
+    }
+}

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

@@ -3,6 +3,7 @@ import { Observable, BehaviorSubject } from 'rxjs';
 
 import { ImproperlyConfiguredError } from 'app/core/exceptions';
 import { BaseModel, ModelId } from 'app/shared/models/base.model';
+import { CacheService } from './cache.service';
 
 /**
  * represents a collection on the Django server, uses an ID to access a {@link BaseModel}.
@@ -53,7 +54,9 @@ export class DataStoreService {
      * Empty constructor for dataStore
      * @param http use HttpClient to send models back to the server
      */
-    constructor() {}
+    constructor(private cacheService: CacheService) {
+        cacheService.test();
+    }
 
     /**
      * Read one, multiple or all ID's from dataStore

client/src/app/openslides.component.ts

@@ -1,23 +1,19 @@
 import { Injector } from '@angular/core';
-import { HttpClient } from '@angular/common/http';
 import { Observable, of } from 'rxjs';
 
 import { DataStoreService } from './core/services/data-store.service';
+import { CacheService } from './core/services/cache.service';
+import { RootInjector } from './core/rootInjector';
 
 /**
  * injects the {@link DataStoreService} to all its children and provides a generic function to catch errors
  * should be abstract and a mere parent to all {@link DataStoreService} accessors
  */
 export abstract class OpenSlidesComponent {
-    /**
-     * To inject the {@link DataStoreService} into the children of OpenSlidesComponent
-     */
-    protected injector: Injector;
-
     /**
      * The dataStore Service
      */
-    protected dataStore: DataStoreService;
+    private static _DS: DataStoreService;
 
     /**
      * Empty constructor
@@ -25,9 +21,7 @@ export abstract class OpenSlidesComponent {
      * Static injection of {@link DataStoreService} in all child instances of OpenSlidesComponent
      * Throws a warning even tho it is the new syntax. Ignored for now.
      */
-    constructor() {
-        this.injector = Injector.create([{ provide: DataStoreService, useClass: DataStoreService, deps: [] }]);
-    }
+    constructor() {}
 
     /**
      * getter to access the {@link DataStoreService}
@@ -35,10 +29,20 @@ export abstract class OpenSlidesComponent {
      * @return access to dataStoreService
      */
     get DS(): DataStoreService {
-        if (this.dataStore == null) {
-            this.dataStore = this.injector.get(DataStoreService);
+        if (OpenSlidesComponent._DS == null) {
+            const injector = Injector.create(
+                [
+                    {
+                        provide: DataStoreService,
+                        useClass: DataStoreService,
+                        deps: [CacheService]
+                    }
+                ],
+                RootInjector.injector
+            );
+            OpenSlidesComponent._DS = injector.get(DataStoreService);
         }
-        return this.dataStore;
+        return OpenSlidesComponent._DS;
     }
 
     /**

client/src/main.ts

@@ -1,8 +1,9 @@
-import { enableProdMode } from '@angular/core';
+import { enableProdMode, NgModuleRef } from '@angular/core';
 import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
 
 import { AppModule } from './app/app.module';
 import { environment } from './environments/environment';
+import { RootInjector } from 'app/core/rootInjector';
 
 if (environment.production) {
     enableProdMode();
@@ -10,4 +11,7 @@ if (environment.production) {
 
 platformBrowserDynamic()
     .bootstrapModule(AppModule)
+    .then((moduleRef: NgModuleRef<AppModule>) => {
+        RootInjector.injector = moduleRef.injector;
+    })
     .catch(err => console.log(err));