#255 Fetching and parsing browse entries

src/app/core/shared/operators.ts

@@ -0,0 +1,47 @@
+import { Observable } from 'rxjs/Observable';
+import { filter, flatMap, map, tap } from 'rxjs/operators';
+import { hasValueOperator } from '../../shared/empty.util';
+import { DSOSuccessResponse } from '../cache/response-cache.models';
+import { ResponseCacheEntry } from '../cache/response-cache.reducer';
+import { ResponseCacheService } from '../cache/response-cache.service';
+import { RemoteData } from '../data/remote-data';
+import { RestRequest } from '../data/request.models';
+import { RequestEntry } from '../data/request.reducer';
+import { RequestService } from '../data/request.service';
+
+/**
+ * This file contains custom RxJS operators that can be used in multiple places
+ */
+
+export const getRequestFromSelflink = (requestService: RequestService) =>
+  (source: Observable<string>): Observable<RequestEntry> =>
+    source.pipe(
+      flatMap((href: string) => requestService.getByHref(href)),
+      hasValueOperator()
+    );
+
+export const getResponseFromSelflink = (responseCache: ResponseCacheService) =>
+  (source: Observable<string>): Observable<ResponseCacheEntry> =>
+    source.pipe(
+      flatMap((href: string) => responseCache.get(href)),
+      hasValueOperator()
+    );
+
+export const filterSuccessfulResponses = () =>
+  (source: Observable<ResponseCacheEntry>): Observable<ResponseCacheEntry> =>
+    source.pipe(filter((entry: ResponseCacheEntry) => entry.response.isSuccessful));
+
+export const getResourceLinksFromResponse = () =>
+  (source: Observable<ResponseCacheEntry>): Observable<string[]> =>
+    source.pipe(
+      filterSuccessfulResponses(),
+      map((entry: ResponseCacheEntry) => (entry.response as DSOSuccessResponse).resourceSelfLinks),
+    );
+
+export const configureRequest = (requestService: RequestService) =>
+  (source: Observable<RestRequest>): Observable<RestRequest> =>
+    source.pipe(tap((request: RestRequest) => requestService.configure(request)));
+
+export const getRemoteDataPayload = () =>
+  <T>(source: Observable<RemoteData<T>>): Observable<T> =>
+    source.pipe(map((remoteData: RemoteData<T>) => remoteData.payload));