Stats generic service

src/lib/dialog/base-dialog.component.ts

@@ -9,7 +9,7 @@ import { IqserEventTarget } from '../utils';
  * However, some components (e.g. redaction-select, color picker) don't set focus on the input after choosing a value.
  * Also, other components (e.g. dropdown select) trigger a different action on enter, instead of submit.
  *
- * Make sure to remove property type="submit" from the save button and the (submit)="save()" property from the form
+ * Make sure to remove the (submit)="save()" property from the form and to set type="button" on the save button
  * (otherwise the save request will be triggered twice).
  * */
 export abstract class BaseDialogComponent {

src/lib/services/index.ts

@@ -3,3 +3,4 @@ export * from './toaster.service';
 export * from './error-message.service';
 export * from './generic.service';
 export * from './composite-route.guard';
+export * from './stats.service';

src/lib/services/stats.service.ts

@@ -0,0 +1,62 @@
+import { Inject, Injectable, Injector } from '@angular/core';
+import { BehaviorSubject, Observable } from 'rxjs';
+import { HttpClient } from '@angular/common/http';
+import { tap } from 'rxjs/operators';
+import { HeadersConfiguration, mapEach, RequiredParam, Validate } from '../utils';
+
+@Injectable()
+export abstract class StatsService<E, I = E> {
+    private readonly _http = this._injector.get(HttpClient);
+    private readonly _map = new Map<string, BehaviorSubject<E>>();
+
+    protected constructor(
+        protected readonly _injector: Injector,
+        @Inject('ENTITY_PRIMARY_KEY') protected readonly _primaryKey: string,
+        @Inject('ENTITY_CLASS') private readonly _entityClass: new (entityInterface: I, ...args: unknown[]) => E,
+        @Inject('ENTITY_PATH') protected readonly _defaultModelPath: string,
+    ) {}
+
+    @Validate()
+    getFor(@RequiredParam() ids: string[]): Observable<E[]> {
+        const request = this._http.post<I[]>(`/${encodeURI(this._defaultModelPath)}`, ids, {
+            headers: HeadersConfiguration.getHeaders(),
+            observe: 'body',
+        });
+
+        return request.pipe(
+            mapEach(entity => new this._entityClass(entity)),
+            tap(entities => entities.forEach(entity => this.set(entity))),
+        );
+    }
+
+    get(key: string): E {
+        return this._getBehaviourSubject(key).value;
+    }
+
+    set(stats: E): void {
+        if (!this._map.has(this._pluckPrimaryKey(stats))) {
+            this._map.set(this._pluckPrimaryKey(stats), new BehaviorSubject<E>(stats));
+            return;
+        }
+
+        const old = this.get(this._pluckPrimaryKey(stats));
+        if (JSON.stringify(old) !== JSON.stringify(stats)) {
+            this._getBehaviourSubject(this._pluckPrimaryKey(stats)).next(stats);
+        }
+    }
+
+    watch$(key: string): Observable<E> {
+        return this._getBehaviourSubject(key).asObservable();
+    }
+
+    private _pluckPrimaryKey(stats: E): string {
+        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+        // @ts-ignore
+        return stats[this._primaryKey] as string;
+    }
+
+    private _getBehaviourSubject(key: string): BehaviorSubject<E> {
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+        return this._map.get(key)!;
+    }
+}