Move all state services under a common base class

frontend/src/app/core/state/attachments/attachments.service.ts

@@ -31,10 +31,7 @@ import {
   HttpClient,
   HttpHeaders,
 } from '@angular/common/http';
-import {
-  applyTransaction,
-  QueryEntity,
-} from '@datorama/akita';
+import { applyTransaction } from '@datorama/akita';
 import {
   from,
   Observable,
@@ -42,7 +39,6 @@ import {
 import {
   catchError,
   map,
-  switchMap,
   tap,
 } from 'rxjs/operators';
 import { AttachmentsStore } from 'core-app/core/state/attachments/attachments.store';
@@ -61,13 +57,13 @@ import { HalLink } from 'core-app/features/hal/hal-link/hal-link';
 import isNewResource, { HAL_NEW_RESOURCE_ID } from 'core-app/features/hal/helpers/is-new-resource';
 import { ConfigurationService } from 'core-app/core/config/configuration.service';
 import { insertCollectionIntoState } from 'core-app/core/state/collection-store';
+import {
+  CollectionStore,
+  ResourceCollectionService,
+} from 'core-app/core/state/resource-collection.service';
 
 @Injectable()
-export class AttachmentsResourceService {
-  protected store = new AttachmentsStore();
-
-  public query = new QueryEntity(this.store);
-
+export class AttachmentsResourceService extends ResourceCollectionService<IAttachment> {
   constructor(
     private readonly I18n:I18nService,
     private readonly http:HttpClient,
@@ -76,7 +72,9 @@ export class AttachmentsResourceService {
     private readonly directFileUploadService:OpenProjectDirectFileUploadService,
     private readonly configurationService:ConfigurationService,
     private readonly toastService:ToastService,
-  ) { }
+  ) {
+    super();
+  }
 
   /**
    * This method ensures that a specific collection is fetched, if not available.
@@ -91,20 +89,6 @@ export class AttachmentsResourceService {
     this.fetchAttachments(key).subscribe();
   }
 
-  /**
-   * Returns an observable of all attachments in a collection identified by the collection key.
-   *
-   * @param key the collection key
-   */
-  collection(key:string):Observable<IAttachment[]> {
-    return this.query
-      .select()
-      .pipe(
-        map((state) => state.collections[key]?.ids),
-        switchMap((attachmentIds) => this.query.selectMany(attachmentIds)),
-      );
-  }
-
   /**
    * Fetches attachments by the attachment collection self link.
    * This link is used as key to store the result collection in the resource store.
@@ -273,4 +257,8 @@ export class AttachmentsResourceService {
     const attachments = resource.attachments as unknown&{ href?:string };
     return attachments?.href || null;
   }
+
+  protected createStore():CollectionStore<IAttachment> {
+    return new AttachmentsStore();
+  }
 }

frontend/src/app/core/state/capabilities/capabilities.service.ts

@@ -4,7 +4,6 @@ import {
   tap,
 } from 'rxjs/operators';
 import { Observable } from 'rxjs';
-import { ID } from '@datorama/akita';
 import { HttpClient } from '@angular/common/http';
 import { ApiV3Service } from 'core-app/core/apiv3/api-v3.service';
 import { ToastService } from 'core-app/shared/components/toaster/toast.service';
@@ -16,14 +15,13 @@ import {
 } from 'core-app/core/state/collection-store';
 import { ICapability } from 'core-app/core/state/capabilities/capability.model';
 import { CapabilitiesStore } from 'core-app/core/state/capabilities/capabilities.store';
-import { CapabilitiesQuery } from 'core-app/core/state/capabilities/capabilities.query';
+import {
+  CollectionStore,
+  ResourceCollectionService,
+} from 'core-app/core/state/resource-collection.service';
 
 @Injectable()
-export class CapabilitiesResourceService {
-  protected store = new CapabilitiesStore();
-
-  readonly query = new CapabilitiesQuery(this.store);
-
+export class CapabilitiesResourceService extends ResourceCollectionService<ICapability> {
   private get capabilitiesPath():string {
     return this
       .apiV3Service
@@ -36,6 +34,7 @@ export class CapabilitiesResourceService {
     private apiV3Service:ApiV3Service,
     private toastService:ToastService,
   ) {
+    super();
   }
 
   fetchCapabilities(params:ApiV3ListParameters):Observable<IHALCollection<ICapability>> {
@@ -53,7 +52,7 @@ export class CapabilitiesResourceService {
       );
   }
 
-  update(id:ID, project:Partial<ICapability>):void {
-    this.store.update(id, project);
+  protected createStore():CollectionStore<ICapability> {
+    return new CapabilitiesStore();
   }
 }

frontend/src/app/core/state/collection-store.ts

@@ -82,3 +82,18 @@ export function insertCollectionIntoState<T extends { id:ID }>(
     ));
   });
 }
+
+export function collectionFrom<T>(elements:T[]):IHALCollection<T> {
+  const count = elements.length;
+
+  return {
+    _type: 'Collection',
+    count,
+    total: count,
+    pageSize: count,
+    offset: 1,
+    _embedded: {
+      elements,
+    },
+  };
+}

frontend/src/app/core/state/file-links/file-links.service.ts

@@ -28,10 +28,14 @@
 
 import { Injectable } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
-import { QueryEntity } from '@datorama/akita';
-import { from, Observable } from 'rxjs';
+import { from } from 'rxjs';
 import {
-  catchError, groupBy, map, mergeMap, reduce, switchMap, tap,
+  catchError,
+  groupBy,
+  mergeMap,
+  reduce,
+  switchMap,
+  tap,
 } from 'rxjs/operators';
 import { IFileLink } from 'core-app/core/state/file-links/file-link.model';
 import { IHALCollection } from 'core-app/core/apiv3/types/hal-collection.type';
@@ -39,15 +43,19 @@ import { ToastService } from 'core-app/shared/components/toaster/toast.service';
 import { FileLinksStore } from 'core-app/core/state/file-links/file-links.store';
 import { insertCollectionIntoState } from 'core-app/core/state/collection-store';
 import idFromLink from 'core-app/features/hal/helpers/id-from-link';
+import {
+  CollectionStore,
+  ResourceCollectionService,
+} from 'core-app/core/state/resource-collection.service';
 
 @Injectable()
-export class FileLinksResourceService {
-  private store = new FileLinksStore();
-
+export class FileLinksResourceService extends ResourceCollectionService<IFileLink> {
   constructor(
     private readonly http:HttpClient,
     private readonly toastService:ToastService,
-  ) {}
+  ) {
+    super();
+  }
 
   updateCollectionsForWorkPackage(fileLinksSelfLink:string):void {
     this.http
@@ -79,13 +87,7 @@ export class FileLinksResourceService {
       });
   }
 
-  collection(key:string):Observable<IFileLink[]> {
-    const query = new QueryEntity(this.store);
-    return query
-      .select()
-      .pipe(
-        map((state) => state.collections[key]?.ids),
-        switchMap((fileLinkIds) => query.selectMany(fileLinkIds)),
-      );
+  protected createStore():CollectionStore<IFileLink> {
+    return new FileLinksStore();
   }
 }

frontend/src/app/core/state/principals/principals.query.ts

@@ -1,10 +0,0 @@
-import { QueryEntity } from '@datorama/akita';
-import { Observable } from 'rxjs';
-import { IPrincipal } from './principal.model';
-import { PrincipalsState } from './principals.store';
-
-export class PrincipalsQuery extends QueryEntity<PrincipalsState> {
-  public byIds(ids:string[]):Observable<IPrincipal[]> {
-    return this.selectMany(ids);
-  }
-}

frontend/src/app/core/state/principals/principals.service.ts

@@ -4,35 +4,29 @@ import {
   tap,
 } from 'rxjs/operators';
 import { Observable } from 'rxjs';
-import {
-  applyTransaction,
-  ID,
-} from '@datorama/akita';
+import { applyTransaction } from '@datorama/akita';
 import { ApiV3Service } from 'core-app/core/apiv3/api-v3.service';
 import { ToastService } from 'core-app/shared/components/toaster/toast.service';
 import { IHALCollection } from 'core-app/core/apiv3/types/hal-collection.type';
 import { HttpClient } from '@angular/common/http';
-import { PrincipalsQuery } from 'core-app/core/state/principals/principals.query';
 import { ApiV3ListParameters } from 'core-app/core/apiv3/paths/apiv3-list-resource.interface';
 import {
   collectionKey,
   insertCollectionIntoState,
 } from 'core-app/core/state/collection-store';
-import {
-  EffectHandler,
-} from 'core-app/core/state/effects/effect-handler.decorator';
+import { EffectHandler } from 'core-app/core/state/effects/effect-handler.decorator';
 import { ActionsService } from 'core-app/core/state/actions/actions.service';
 import { PrincipalsStore } from './principals.store';
 import { IPrincipal } from './principal.model';
 import { IUser } from 'core-app/core/state/principals/user.model';
+import {
+  CollectionStore,
+  ResourceCollectionService,
+} from 'core-app/core/state/resource-collection.service';
 
 @EffectHandler
 @Injectable()
-export class PrincipalsResourceService {
-  protected store = new PrincipalsStore();
-
-  readonly query = new PrincipalsQuery(this.store);
-
+export class PrincipalsResourceService extends ResourceCollectionService<IPrincipal> {
   private get principalsPath():string {
     return this
       .apiV3Service
@@ -45,7 +39,9 @@ export class PrincipalsResourceService {
     private http:HttpClient,
     private apiV3Service:ApiV3Service,
     private toastService:ToastService,
-  ) { }
+  ) {
+    super();
+  }
 
   fetchUser(id:string|number):Observable<IUser> {
     return this.http
@@ -78,37 +74,7 @@ export class PrincipalsResourceService {
       );
   }
 
-  update(id:ID, principal:Partial<IPrincipal>):void {
-    this.store.update(id, principal);
-  }
-
-  modifyCollection(params:ApiV3ListParameters, callback:(collection:ID[]) => ID[]):void {
-    const key = collectionKey(params);
-    this.store.update(({ collections }) => (
-      {
-        collections: {
-          ...collections,
-          [key]: {
-            ...collections[key],
-            ids: [...callback(collections[key]?.ids || [])],
-          },
-        },
-      }
-    ));
-  }
-
-  removeFromCollection(params:ApiV3ListParameters, ids:ID[]):void {
-    const key = collectionKey(params);
-    this.store.update(({ collections }) => (
-      {
-        collections: {
-          ...collections,
-          [key]: {
-            ...collections[key],
-            ids: (collections[key]?.ids || []).filter((id) => !ids.includes(id)),
-          },
-        },
-      }
-    ));
+  protected createStore():CollectionStore<IPrincipal> {
+    return new PrincipalsStore();
   }
 }

frontend/src/app/core/state/projects/projects.service.ts

@@ -27,32 +27,29 @@
 //++
 
 import { Injectable } from '@angular/core';
-import { catchError, filter, tap } from 'rxjs/operators';
+import {
+  catchError,
+  tap,
+} from 'rxjs/operators';
 import { Observable } from 'rxjs';
-import { ID } from '@datorama/akita';
 import { HttpClient } from '@angular/common/http';
 import { ApiV3Service } from 'core-app/core/apiv3/api-v3.service';
 import { ToastService } from 'core-app/shared/components/toaster/toast.service';
 import { IHALCollection } from 'core-app/core/apiv3/types/hal-collection.type';
-import { ProjectsQuery } from 'core-app/core/state/projects/projects.query';
 import { ApiV3ListParameters } from 'core-app/core/apiv3/paths/apiv3-list-resource.interface';
 import {
   collectionKey,
   insertCollectionIntoState,
 } from 'core-app/core/state/collection-store';
-import { ProjectsStore } from './projects.store';
 import { IProject } from './project.model';
-
-export function isIProject(input:IProject|undefined):input is IProject {
-  return input !== undefined;
-}
+import {
+  CollectionStore,
+  ResourceCollectionService,
+} from 'core-app/core/state/resource-collection.service';
+import { ProjectsStore } from 'core-app/core/state/projects/projects.store';
 
 @Injectable()
-export class ProjectsResourceService {
-  protected store = new ProjectsStore();
-
-  readonly query = new ProjectsQuery(this.store);
-
+export class ProjectsResourceService extends ResourceCollectionService<IProject> {
   private get projectsPath():string {
     return this
       .apiV3Service
@@ -65,6 +62,7 @@ export class ProjectsResourceService {
     private apiV3Service:ApiV3Service,
     private toastService:ToastService,
   ) {
+    super();
   }
 
   fetchProjects(params:ApiV3ListParameters):Observable<IHALCollection<IProject>> {
@@ -91,9 +89,7 @@ export class ProjectsResourceService {
       );
   }
 
-  lookup(id:ID):Observable<IProject> {
-    return this.query
-      .selectEntity(id)
-      .pipe(filter(isIProject));
+  protected createStore():CollectionStore<IProject> {
+    return new ProjectsStore();
   }
 }

frontend/src/app/core/state/resource-collection.service.ts

@@ -74,6 +74,38 @@ export abstract class ResourceCollectionService<T> {
       ) as Observable<T>;
   }
 
+  /**
+   * Lookup multiple entities from the store
+   */
+  lookupMany(ids:ID[]):Observable<T[]> {
+    return this
+      .query
+      .selectMany(ids);
+  }
+
+  /**
+   * Lookup a single entity from the store
+   * @param id
+   */
+  lookupMultiple(id:ID):Observable<T> {
+    return this
+      .query
+      .selectEntity(id)
+      .pipe(
+        filter((entity) => entity !== undefined),
+      ) as Observable<T>;
+  }
+
+  /**
+   * Update a single entity in the store
+   *
+   * @param id The id to update
+   * @param entity A section of the entity to update
+   */
+  update(id:ID, entity:Partial<T>):void {
+    this.store.update(id, entity);
+  }
+
   /**
    * Create a new instance of this resource service's underyling store.
    * @protected

frontend/src/app/core/state/storages/storages.service.ts

@@ -28,42 +28,21 @@
 
 import { Injectable } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
-import { forkJoin, Observable } from 'rxjs';
-import { filter, map, switchMap } from 'rxjs/operators';
+import { forkJoin } from 'rxjs';
 import { IStorage } from 'core-app/core/state/storages/storage.model';
 import { StoragesStore } from 'core-app/core/state/storages/storages.store';
-import { StoragesQuery } from 'core-app/core/state/storages/storages.query';
 import { insertCollectionIntoState } from 'core-app/core/state/collection-store';
 import { IHALCollection } from 'core-app/core/apiv3/types/hal-collection.type';
 import { IHalResourceLink } from 'core-app/core/state/hal-resource';
-
-export function isIStorage(input:IStorage|undefined):input is IStorage {
-  return input !== undefined;
-}
+import {
+  CollectionStore,
+  ResourceCollectionService,
+} from 'core-app/core/state/resource-collection.service';
 
 @Injectable()
-export class StoragesResourceService {
-  private readonly store = new StoragesStore();
-
-  private readonly query = new StoragesQuery(this.store);
-
-  constructor(private readonly http:HttpClient) {}
-
-  collection(key:string):Observable<IStorage[]> {
-    return this
-      .query
-      .select()
-      .pipe(
-        map((state) => state.collections[key]?.ids),
-        switchMap((ids) => this.query.selectMany(ids)),
-      );
-  }
-
-  lookup(id:string):Observable<IStorage> {
-    return this
-      .query
-      .selectEntity(id)
-      .pipe(filter(isIStorage));
+export class StoragesResourceService extends ResourceCollectionService<IStorage> {
+  constructor(private readonly http:HttpClient) {
+    super();
   }
 
   updateCollection(key:string, storageLinks:IHalResourceLink[]):void {
@@ -74,4 +53,8 @@ export class StoragesResourceService {
       insertCollectionIntoState(this.store, storageCollection, key);
     });
   }
+
+  protected createStore():CollectionStore<IStorage> {
+    return new StoragesStore();
+  }
 }

frontend/src/app/core/state/views/views.service.ts

@@ -11,7 +11,10 @@ import {
 import { ToastService } from 'core-app/shared/components/toaster/toast.service';
 import { IHALCollection } from 'core-app/core/apiv3/types/hal-collection.type';
 import { HttpClient } from '@angular/common/http';
-import { collectionKey } from 'core-app/core/state/collection-store';
+import {
+  collectionKey,
+  insertCollectionIntoState,
+} from 'core-app/core/state/collection-store';
 import {
   EffectHandler,
 } from 'core-app/core/state/effects/effect-handler.decorator';
@@ -22,14 +25,14 @@ import { IView } from 'core-app/core/state/views/view.model';
 import { ApiV3Service } from 'core-app/core/apiv3/api-v3.service';
 import { ApiV3ListParameters } from 'core-app/core/apiv3/paths/apiv3-list-resource.interface';
 import { addParamToHref } from 'core-app/shared/helpers/url-helpers';
+import {
+  CollectionStore,
+  ResourceCollectionService,
+} from 'core-app/core/state/resource-collection.service';
 
 @EffectHandler
 @Injectable()
-export class ViewsResourceService {
-  protected store = new ViewsStore();
-
-  readonly query = new ViewsQuery(this.store);
-
+export class ViewsResourceService extends ResourceCollectionService<IView> {
   private get viewsPath():string {
     return this
       .apiV3Service
@@ -43,6 +46,7 @@ export class ViewsResourceService {
     private apiV3Service:ApiV3Service,
     private toastService:ToastService,
   ) {
+    super();
   }
 
   fetchViews(params:ApiV3ListParameters):Observable<IHALCollection<IView>> {
@@ -52,22 +56,7 @@ export class ViewsResourceService {
       .http
       .get<IHALCollection<IView>>(addParamToHref(this.viewsPath + collectionURL, { pageSize: '-1' }))
       .pipe(
-        tap((events) => {
-          applyTransaction(() => {
-            this.store.upsertMany(events._embedded.elements);
-            this.store.update(({ collections }) => (
-              {
-                collections: {
-                  ...collections,
-                  [collectionURL]: {
-                    ...collections[collectionURL],
-                    ids: events._embedded.elements.map((el) => el.id),
-                  },
-                },
-              }
-            ));
-          });
-        }),
+        tap((collection) => insertCollectionIntoState(this.store, collection, collectionURL)),
         catchError((error) => {
           this.toastService.addError(error);
           throw error;
@@ -75,37 +64,7 @@ export class ViewsResourceService {
       );
   }
 
-  update(id:ID, view:Partial<IView>):void {
-    this.store.update(id, view);
-  }
-
-  modifyCollection(params:ApiV3ListParameters, callback:(collection:ID[]) => ID[]):void {
-    const key = collectionKey(params);
-    this.store.update(({ collections }) => (
-      {
-        collections: {
-          ...collections,
-          [key]: {
-            ...collections[key],
-            ids: [...callback(collections[key]?.ids || [])],
-          },
-        },
-      }
-    ));
-  }
-
-  removeFromCollection(params:ApiV3ListParameters, ids:ID[]):void {
-    const key = collectionKey(params);
-    this.store.update(({ collections }) => (
-      {
-        collections: {
-          ...collections,
-          [key]: {
-            ...collections[key],
-            ids: (collections[key]?.ids || []).filter((id) => !ids.includes(id)),
-          },
-        },
-      }
-    ));
+  protected createStore():CollectionStore<IView> {
+    return new ViewsStore();
   }
 }

frontend/src/app/features/in-app-notifications/center/menu/menu.component.ts

@@ -94,7 +94,7 @@ export class IanMenuComponent implements OnInit {
     },
   ];
 
-  notificationsByProject$ = this.ianMenuService.query.notificationsByProject$.pipe(
+  notificationsByProject$ = this.ianMenuService.notificationsByProject$.pipe(
     map((items) => items
       .map((item) => ({
         ...item,
@@ -110,7 +110,7 @@ export class IanMenuComponent implements OnInit {
       })),
   );
 
-  notificationsByReason$ = this.ianMenuService.query.notificationsByReason$.pipe(
+  notificationsByReason$ = this.ianMenuService.notificationsByReason$.pipe(
     map((items) => this.reasonMenuItems.map((reason) => ({
       ...items.find((item) => item.value === reason.key),
       ...reason,

frontend/src/app/features/in-app-notifications/center/menu/state/ian-menu.query.ts

@@ -1,54 +0,0 @@
-import { Query } from '@datorama/akita';
-import { combineLatest } from 'rxjs';
-import { map } from 'rxjs/operators';
-import idFromLink from 'core-app/features/hal/helpers/id-from-link';
-import { InAppNotificationsResourceService } from 'core-app/core/state/in-app-notifications/in-app-notifications.service';
-import { ProjectsResourceService } from 'core-app/core/state/projects/projects.service';
-import { IProject } from 'core-app/core/state/projects/project.model';
-import { collectionKey } from 'core-app/core/state/collection-store';
-import {
-  IanMenuState,
-  IanMenuStore,
-} from './ian-menu.store';
-
-export class IanMenuQuery extends Query<IanMenuState> {
-  projectsFilter$ = this.select('projectsFilter');
-
-  projectsForNotifications$ = combineLatest([
-    this.projectsFilter$,
-    this.projectsResourceService.query.select(),
-  ]).pipe(
-    map(([filterParams, collectionData]) => {
-      const key = collectionKey(filterParams);
-      const collection = collectionData.collections[key];
-      const ids = collection?.ids || [];
-
-      return ids
-        .map((id:string) => this.projectsResourceService.query.getEntity(id))
-        .filter((item:IProject|undefined) => !!item) as IProject[];
-    }),
-  );
-
-  notificationsByProject$ = combineLatest([
-    this.select('notificationsByProject'),
-    this.projectsForNotifications$,
-  ]).pipe(
-    map(([notifications, projects]) => notifications.map((notification) => {
-      const project = projects.find((p) => p.id.toString() === idFromLink(notification._links.valueLink[0].href));
-      return {
-        ...notification,
-        projectHasParent: !!project?._links.parent.href,
-      };
-    })),
-  );
-
-  notificationsByReason$ = this.select('notificationsByReason');
-
-  constructor(
-    protected store:IanMenuStore,
-    protected resourceService:InAppNotificationsResourceService,
-    protected projectsResourceService:ProjectsResourceService,
-  ) {
-    super(store);
-  }
-}

frontend/src/app/features/in-app-notifications/center/menu/state/ian-menu.service.ts

@@ -3,8 +3,8 @@ import {
   Injector,
 } from '@angular/core';
 import {
-  notificationsMarkedRead,
   notificationCountIncreased,
+  notificationsMarkedRead,
 } from 'core-app/core/state/in-app-notifications/in-app-notifications.actions';
 import {
   EffectCallback,
@@ -16,12 +16,18 @@ import { ApiV3ListParameters } from 'core-app/core/apiv3/paths/apiv3-list-resour
 import idFromLink from 'core-app/features/hal/helpers/id-from-link';
 import { InAppNotificationsResourceService } from 'core-app/core/state/in-app-notifications/in-app-notifications.service';
 import { ProjectsResourceService } from 'core-app/core/state/projects/projects.service';
-import { IanMenuQuery } from './ian-menu.query';
 import {
-  IanMenuStore,
   IAN_MENU_PROJECT_FILTERS,
   IAN_MENU_REASON_FILTERS,
+  IanMenuStore,
 } from './ian-menu.store';
+import { Query } from '@datorama/akita';
+import {
+  map,
+  switchMap,
+} from 'rxjs/operators';
+import { collectionKey } from 'core-app/core/state/collection-store';
+import { combineLatest } from 'rxjs';
 
 @Injectable()
 @EffectHandler
@@ -30,7 +36,33 @@ export class IanMenuService {
 
   readonly store = new IanMenuStore();
 
-  readonly query = new IanMenuQuery(this.store, this.ianResourceService, this.projectsResourceService);
+  readonly query = new Query(this.store);
+
+  projectsFilter$ = this.query.select('projectsFilter');
+
+  projectsForNotifications$ = this
+    .projectsFilter$
+    .pipe(
+      switchMap((filterParams) => {
+        const key = collectionKey(filterParams);
+        return this.projectsResourceService.collection(key);
+      }),
+    );
+
+  notificationsByProject$ = combineLatest([
+    this.query.select('notificationsByProject'),
+    this.projectsForNotifications$,
+  ]).pipe(
+    map(([notifications, projects]) => notifications.map((notification) => {
+      const project = projects.find((p) => p.id.toString() === idFromLink(notification._links.valueLink[0].href));
+      return {
+        ...notification,
+        projectHasParent: !!project?._links.parent.href,
+      };
+    })),
+  );
+
+  notificationsByReason$ = this.query.select('notificationsByReason');
 
   constructor(
     readonly injector:Injector,

frontend/src/app/features/in-app-notifications/center/state/ian-center.service.ts

@@ -4,6 +4,7 @@ import {
 } from '@angular/core';
 import {
   debounceTime,
+  defaultIfEmpty,
   distinctUntilChanged,
   map,
   mapTo,
@@ -85,7 +86,11 @@ export class IanCenterService extends UntilDestroyedMixin {
   selectNotifications$:Observable<INotification[]> = this
     .activeCollection$
     .pipe(
-      switchMap((collection) => forkJoin(collection.ids.map((id) => this.resourceService.lookup(id)))),
+      switchMap((collection) => {
+        const lookupId = (id:ID) => this.resourceService.lookup(id).pipe(take(1));
+        return forkJoin(collection.ids.map(lookupId))
+          .pipe(defaultIfEmpty([]));
+      }),
     );
 
   aggregatedCenterNotifications$ = this

frontend/src/app/features/team-planner/team-planner/planner/team-planner.component.ts

@@ -266,7 +266,7 @@ export class TeamPlannerComponent extends UntilDestroyedMixin implements OnInit,
   principals$ = this.principalIds$
     .pipe(
       this.untilDestroyed(),
-      mergeMap((ids:string[]) => this.principalsResourceService.query.byIds(ids)),
+      mergeMap((ids:string[]) => this.principalsResourceService.lookupMany(ids)),
       debounceTime(50),
       distinctUntilChanged((prev, curr) => prev.length === curr.length && prev.length === 0),
       shareReplay(1),

frontend/src/app/shared/components/attachments/attachment-list/attachment-list-item.component.ts

@@ -77,7 +77,9 @@ export class AttachmentListItemComponent implements OnInit {
   ngOnInit():void {
     const authorId = idFromLink(this.attachment._links.author.href);
 
-    this.author$ = this.principalsResourceService.query.selectEntity(authorId)
+    this.author$ = this
+      .principalsResourceService
+      .lookup(authorId)
       .pipe(
         switchMap((user) => (user ? of(user) : this.principalsResourceService.fetchUser(authorId))),
         map((user) => user as IUser),

frontend/src/app/shared/components/attachments/attachment-list/attachment-list.component.ts

@@ -37,7 +37,7 @@ import { HalResource } from 'core-app/features/hal/resources/hal-resource';
 import { IAttachment } from 'core-app/core/state/attachments/attachment.model';
 import { UntilDestroyedMixin } from 'core-app/shared/helpers/angular/until-destroyed.mixin';
 import { AttachmentsResourceService } from 'core-app/core/state/attachments/attachments.service';
-import { map, switchMap, tap } from 'rxjs/operators';
+import { tap } from 'rxjs/operators';
 import isNewResource from 'core-app/features/hal/helpers/is-new-resource';
 import { Observable } from 'rxjs';
 
@@ -72,12 +72,11 @@ export class AttachmentListComponent extends UntilDestroyedMixin implements OnIn
       this.attachmentsResourceService.requireCollection(this.attachmentsSelfLink);
     }
 
-    this.$attachments = this.attachmentsResourceService.query.select()
+    this.$attachments = this
+      .attachmentsResourceService
+      .collection(this.collectionKey)
       .pipe(
         this.untilDestroyed(),
-        map((state) => state.collections[this.collectionKey]?.ids),
-        switchMap((attachmentIds) => this.attachmentsResourceService.query.selectMany(attachmentIds)),
-
         // store attachments for new resources directly into the resource. This way, the POST request to create the
         // resource embeds the attachments and the backend reroutes the anonymous attachments to the resource.
         tap((attachments) => {