Refactored Data Services

src/app/core/cache/object-cache.service.ts

@@ -0,0 +1,58 @@
+import { Injectable } from "@angular/core";
+import { Store } from "@ngrx/store";
+import { ObjectCacheState, ObjectCacheEntry, CacheableObject } from "./object-cache.reducer";
+import { AddToObjectCacheAction, RemoveFromObjectCacheAction } from "./object-cache.actions";
+import { Observable } from "rxjs";
+import { hasNoValue } from "../../shared/empty.util";
+
+@Injectable()
+export class ObjectCacheService {
+  constructor(
+    private store: Store<ObjectCacheState>
+  ) {}
+
+  add(objectToCache: CacheableObject, msToLive: number): void {
+    this.store.dispatch(new AddToObjectCacheAction(objectToCache, msToLive));
+  }
+
+  remove(uuid: string): void {
+    this.store.dispatch(new RemoveFromObjectCacheAction(uuid));
+  }
+
+  get<T extends CacheableObject>(uuid: string): Observable<T> {
+    return this.store.select<ObjectCacheEntry>('core', 'cache', 'object', uuid)
+      .filter(entry => this.isValid(entry))
+      .map((entry: ObjectCacheEntry) => <T> entry.data);
+  }
+
+  getList<T extends CacheableObject>(uuids: Array<string>): Observable<Array<T>> {
+    return Observable.combineLatest(
+      uuids.map((id: string) => this.get<T>(id))
+    );
+  }
+
+  has(uuid: string): boolean {
+    let result: boolean;
+
+    this.store.select<ObjectCacheEntry>('core', 'cache', 'object', uuid)
+      .take(1)
+      .subscribe(entry => result = this.isValid(entry));
+
+    return result;
+  }
+
+  private isValid(entry: ObjectCacheEntry): boolean {
+    if (hasNoValue(entry)) {
+      return false;
+    }
+    else {
+      const timeOutdated = entry.timeAdded + entry.msToLive;
+      const isOutDated = new Date().getTime() > timeOutdated;
+      if (isOutDated) {
+        this.store.dispatch(new RemoveFromObjectCacheAction(entry.data.uuid));
+      }
+      return !isOutDated;
+    }
+  }
+
+}