Added services and models

src/app/core/tasks/tasks.service.ts

@@ -0,0 +1,82 @@
+import { HttpHeaders } from '@angular/common/http';
+
+import { merge as observableMerge, Observable, of as observableOf } from 'rxjs';
+import { distinctUntilChanged, filter, flatMap, map, mergeMap, tap } from 'rxjs/operators';
+
+import { DataService } from '../data/data.service';
+import { DeleteRequest, FindAllOptions, PostRequest, TaskDeleteRequest, TaskPostRequest } from '../data/request.models';
+import { isNotEmpty } from '../../shared/empty.util';
+import { HttpOptions } from '../dspace-rest-v2/dspace-rest-v2.service';
+import { ProcessTaskResponse } from './models/process-task-response';
+import { RemoteDataError } from '../data/remote-data-error';
+import { NormalizedObject } from '../cache/models/normalized-object.model';
+import { getResponseFromEntry } from '../shared/operators';
+import { ErrorResponse, MessageResponse, RestResponse } from '../cache/response.models';
+import { CacheableObject } from '../cache/object-cache.reducer';
+
+export abstract class TasksService<TNormalized extends NormalizedObject, TDomain extends CacheableObject> extends DataService<TNormalized, TDomain> {
+
+  public getBrowseEndpoint(options: FindAllOptions): Observable<string> {
+    return this.halService.getEndpoint(this.linkPath);
+  }
+
+  protected fetchRequest(requestId: string): Observable<ProcessTaskResponse> {
+    const responses = this.requestService.getByUUID(requestId).pipe(
+      getResponseFromEntry()
+    );
+    const errorResponses = responses.pipe(
+      filter((response: RestResponse) => !response.isSuccessful),
+      mergeMap((response: ErrorResponse) => observableOf(
+        new ProcessTaskResponse(
+          response.isSuccessful,
+          new RemoteDataError(response.statusCode, response.statusText, response.errorMessage)
+        ))
+      ));
+    const successResponses = responses.pipe(
+      filter((response: RestResponse) => response.isSuccessful),
+      map((response: MessageResponse) =>  new ProcessTaskResponse(response.isSuccessful)),
+      distinctUntilChanged()
+    );
+    return observableMerge(errorResponses, successResponses);
+  }
+
+  protected getEndpointByIDHref(endpoint, resourceID): string {
+    return isNotEmpty(resourceID) ? `${endpoint}/${resourceID}` : `${endpoint}`;
+  }
+
+  protected getEndpointByMethod(endpoint: string, method: string): string {
+    return isNotEmpty(method) ? `${endpoint}/${method}` : `${endpoint}`;
+  }
+
+  public postToEndpoint(linkPath: string, body: any, scopeId?: string, options?: HttpOptions): Observable<ProcessTaskResponse> {
+    const requestId = this.requestService.generateRequestId();
+    return this.halService.getEndpoint(linkPath).pipe(
+      filter((href: string) => isNotEmpty(href)),
+      map((endpointURL: string) => this.getEndpointByIDHref(endpointURL, scopeId)),
+      distinctUntilChanged(),
+      map((endpointURL: string) => new TaskPostRequest(requestId, endpointURL, body, options)),
+      tap((request: PostRequest) => this.requestService.configure(request)),
+      flatMap((request: PostRequest) => this.fetchRequest(requestId)),
+      distinctUntilChanged());
+  }
+
+  public deleteById(linkName: string, scopeId: string, options?: HttpOptions): Observable<ProcessTaskResponse> {
+    const requestId = this.requestService.generateRequestId();
+    return this.halService.getEndpoint(linkName || this.linkPath).pipe(
+      filter((href: string) => isNotEmpty(href)),
+      distinctUntilChanged(),
+      map((endpointURL: string) => this.getEndpointByIDHref(endpointURL, scopeId)),
+      map((endpointURL: string) => new TaskDeleteRequest(requestId, endpointURL, null, options)),
+      tap((request: DeleteRequest) => this.requestService.configure(request)),
+      flatMap((request: DeleteRequest) => this.fetchRequest(requestId)),
+      distinctUntilChanged());
+  }
+
+  protected makeHttpOptions() {
+    const options: HttpOptions = Object.create({});
+    let headers = new HttpHeaders();
+    headers = headers.append('Content-Type', 'application/x-www-form-urlencoded');
+    options.headers = headers;
+    return options;
+  }
+}