Merge pull request DSpace#2248 from 4Science/feature/CST-5729

Implement Signposting on angular side

Author: tdonohue

server.ts

@@ -26,15 +26,14 @@ import * as ejs from 'ejs';
 import * as compression from 'compression';
 import * as expressStaticGzip from 'express-static-gzip';
 /* eslint-enable import/no-namespace */
-
 import axios from 'axios';
 import LRU from 'lru-cache';
 import isbot from 'isbot';
 import { createCertificate } from 'pem';
 import { createServer } from 'https';
 import { json } from 'body-parser';
 
-import { existsSync, readFileSync } from 'fs';
+import { readFileSync } from 'fs';
 import { join } from 'path';
 
 import { enableProdMode } from '@angular/core';
@@ -180,6 +179,15 @@ export function app() {
     changeOrigin: true
   }));
 
+  /**
+   * Proxy the linksets
+   */
+  router.use('/signposting**', createProxyMiddleware({
+    target: `${environment.rest.baseUrl}`,
+    pathRewrite: path => path.replace(environment.ui.nameSpace, '/'),
+    changeOrigin: true
+  }));
+
   /**
    * Checks if the rateLimiter property is present
    * When it is present, the rateLimiter will be enabled. When it is undefined, the rateLimiter will be disabled.

src/app/bitstream-page/bitstream-download-page/bitstream-download-page.component.spec.ts

@@ -11,6 +11,9 @@ import { ActivatedRoute, Router } from '@angular/router';
 import { getForbiddenRoute } from '../../app-routing-paths';
 import { TranslateModule } from '@ngx-translate/core';
 import { CommonModule } from '@angular/common';
+import { SignpostingDataService } from '../../core/data/signposting-data.service';
+import { ServerResponseService } from '../../core/services/server-response.service';
+import { PLATFORM_ID } from '@angular/core';
 
 describe('BitstreamDownloadPageComponent', () => {
   let component: BitstreamDownloadPageComponent;
@@ -24,6 +27,20 @@ describe('BitstreamDownloadPageComponent', () => {
   let router;
 
   let bitstream: Bitstream;
+  let serverResponseService: jasmine.SpyObj<ServerResponseService>;
+  let signpostingDataService: jasmine.SpyObj<SignpostingDataService>;
+
+  const mocklink = {
+    href: 'http://test.org',
+    rel: 'test',
+    type: 'test'
+  };
+
+  const mocklink2 = {
+    href: 'http://test2.org',
+    rel: 'test',
+    type: 'test'
+  };
 
   function init() {
     authService = jasmine.createSpyObj('authService', {
@@ -44,8 +61,8 @@ describe('BitstreamDownloadPageComponent', () => {
     bitstream = Object.assign(new Bitstream(), {
       uuid: 'bitstreamUuid',
       _links: {
-        content: {href: 'bitstream-content-link'},
-        self: {href: 'bitstream-self-link'},
+        content: { href: 'bitstream-content-link' },
+        self: { href: 'bitstream-self-link' },
       }
     });
 
@@ -54,23 +71,37 @@ describe('BitstreamDownloadPageComponent', () => {
         bitstream: createSuccessfulRemoteDataObject(
           bitstream
         )
+      }),
+      params: observableOf({
+        id: 'testid'
       })
     };
 
     router = jasmine.createSpyObj('router', ['navigateByUrl']);
+
+    serverResponseService = jasmine.createSpyObj('ServerResponseService', {
+      setHeader: jasmine.createSpy('setHeader'),
+    });
+
+    signpostingDataService = jasmine.createSpyObj('SignpostingDataService', {
+      getLinks: observableOf([mocklink, mocklink2])
+    });
   }
 
   function initTestbed() {
     TestBed.configureTestingModule({
       imports: [CommonModule, TranslateModule.forRoot()],
       declarations: [BitstreamDownloadPageComponent],
       providers: [
-        {provide: ActivatedRoute, useValue: activatedRoute},
-        {provide: Router, useValue: router},
-        {provide: AuthorizationDataService, useValue: authorizationService},
-        {provide: AuthService, useValue: authService},
-        {provide: FileService, useValue: fileService},
-        {provide: HardRedirectService, useValue: hardRedirectService},
+        { provide: ActivatedRoute, useValue: activatedRoute },
+        { provide: Router, useValue: router },
+        { provide: AuthorizationDataService, useValue: authorizationService },
+        { provide: AuthService, useValue: authService },
+        { provide: FileService, useValue: fileService },
+        { provide: HardRedirectService, useValue: hardRedirectService },
+        { provide: ServerResponseService, useValue: serverResponseService },
+        { provide: SignpostingDataService, useValue: signpostingDataService },
+        { provide: PLATFORM_ID, useValue: 'server' }
       ]
     })
       .compileComponents();
@@ -107,6 +138,9 @@ describe('BitstreamDownloadPageComponent', () => {
       it('should redirect to the content link', () => {
         expect(hardRedirectService.redirect).toHaveBeenCalledWith('bitstream-content-link');
       });
+      it('should add the signposting links', () => {
+        expect(serverResponseService.setHeader).toHaveBeenCalled();
+      });
     });
     describe('when the user is authorized and logged in', () => {
       beforeEach(waitForAsync(() => {
@@ -134,7 +168,7 @@ describe('BitstreamDownloadPageComponent', () => {
         fixture.detectChanges();
       });
       it('should navigate to the forbidden route', () => {
-        expect(router.navigateByUrl).toHaveBeenCalledWith(getForbiddenRoute(), {skipLocationChange: true});
+        expect(router.navigateByUrl).toHaveBeenCalledWith(getForbiddenRoute(), { skipLocationChange: true });
       });
     });
     describe('when the user is not authorized and not logged in', () => {

src/app/bitstream-page/bitstream-download-page/bitstream-download-page.component.ts

@@ -1,8 +1,8 @@
-import { Component, OnInit } from '@angular/core';
+import { Component, Inject, OnInit, PLATFORM_ID } from '@angular/core';
 import { filter, map, switchMap, take } from 'rxjs/operators';
 import { ActivatedRoute, Router } from '@angular/router';
 import { hasValue, isNotEmpty } from '../../shared/empty.util';
-import { getRemoteDataPayload} from '../../core/shared/operators';
+import { getRemoteDataPayload } from '../../core/shared/operators';
 import { Bitstream } from '../../core/shared/bitstream.model';
 import { AuthorizationDataService } from '../../core/data/feature-authorization/authorization-data.service';
 import { FeatureID } from '../../core/data/feature-authorization/feature-id';
@@ -13,8 +13,11 @@ import { HardRedirectService } from '../../core/services/hard-redirect.service';
 import { getForbiddenRoute } from '../../app-routing-paths';
 import { RemoteData } from '../../core/data/remote-data';
 import { redirectOn4xx } from '../../core/shared/authorized.operators';
-import { Location } from '@angular/common';
+import { isPlatformServer, Location } from '@angular/common';
 import { DSONameService } from '../../core/breadcrumbs/dso-name.service';
+import { SignpostingDataService } from '../../core/data/signposting-data.service';
+import { ServerResponseService } from '../../core/services/server-response.service';
+import { SignpostingLink } from '../../core/data/signposting-links.model';
 
 @Component({
   selector: 'ds-bitstream-download-page',
@@ -28,7 +31,6 @@ export class BitstreamDownloadPageComponent implements OnInit {
   bitstream$: Observable<Bitstream>;
   bitstreamRD$: Observable<RemoteData<Bitstream>>;
 
-
   constructor(
     private route: ActivatedRoute,
     protected router: Router,
@@ -38,8 +40,11 @@ export class BitstreamDownloadPageComponent implements OnInit {
     private hardRedirectService: HardRedirectService,
     private location: Location,
     public dsoNameService: DSONameService,
+    private signpostingDataService: SignpostingDataService,
+    private responseService: ServerResponseService,
+    @Inject(PLATFORM_ID) protected platformId: string
   ) {
-
+    this.initPageLinks();
   }
 
   back(): void {
@@ -89,4 +94,26 @@ export class BitstreamDownloadPageComponent implements OnInit {
       }
     });
   }
+
+  /**
+   * Create page links if any are retrieved by signposting endpoint
+   *
+   * @private
+   */
+  private initPageLinks(): void {
+    if (isPlatformServer(this.platformId)) {
+      this.route.params.subscribe(params => {
+        this.signpostingDataService.getLinks(params.id).pipe(take(1)).subscribe((signpostingLinks: SignpostingLink[]) => {
+          let links = '';
+
+          signpostingLinks.forEach((link: SignpostingLink) => {
+            links = links + (isNotEmpty(links) ? ', ' : '') + `<${link.href}> ; rel="${link.rel}"` + (isNotEmpty(link.type) ? ` ; type="${link.type}" ` : ' ');
+            links = links + (isNotEmpty(links) ? ', ' : '') + `<${link.href}> ; rel="${link.rel}" ; type="${link.type}" `;
+          });
+
+          this.responseService.setHeader('Link', links);
+        });
+      });
+    }
+  }
 }

src/app/core/data/signposting-data.service.spec.ts

@@ -0,0 +1,97 @@
+import { fakeAsync, TestBed, tick } from '@angular/core/testing';
+import { SignpostingDataService } from './signposting-data.service';
+import { DspaceRestService } from '../dspace-rest/dspace-rest.service';
+import { HALEndpointService } from '../shared/hal-endpoint.service';
+import { of } from 'rxjs';
+import { SignpostingLink } from './signposting-links.model';
+
+describe('SignpostingDataService', () => {
+  let service: SignpostingDataService;
+  let restServiceSpy: jasmine.SpyObj<DspaceRestService>;
+  let halServiceSpy: jasmine.SpyObj<HALEndpointService>;
+  const mocklink = {
+    href: 'http://test.org',
+    rel: 'test',
+    type: 'test'
+  };
+
+  const mocklink2 = {
+    href: 'http://test2.org',
+    rel: 'test',
+    type: 'test'
+  };
+
+  const mockResponse: any = {
+    statusCode: 200,
+    payload: [mocklink, mocklink2]
+  };
+
+  const mockErrResponse: any = {
+    statusCode: 500
+  };
+
+  beforeEach(() => {
+    const restSpy = jasmine.createSpyObj('DspaceRestService', ['get', 'getWithHeaders']);
+    const halSpy = jasmine.createSpyObj('HALEndpointService', ['getRootHref']);
+
+    TestBed.configureTestingModule({
+      providers: [
+        SignpostingDataService,
+        { provide: DspaceRestService, useValue: restSpy },
+        { provide: HALEndpointService, useValue: halSpy }
+      ]
+    });
+
+    service = TestBed.inject(SignpostingDataService);
+    restServiceSpy = TestBed.inject(DspaceRestService) as jasmine.SpyObj<DspaceRestService>;
+    halServiceSpy = TestBed.inject(HALEndpointService) as jasmine.SpyObj<HALEndpointService>;
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+
+  it('should return signposting links', fakeAsync(() => {
+    const uuid = '123';
+    const baseUrl = 'http://localhost:8080';
+
+    halServiceSpy.getRootHref.and.returnValue(`${baseUrl}/api`);
+
+    restServiceSpy.get.and.returnValue(of(mockResponse));
+
+    let result: SignpostingLink[];
+
+    const expectedResult: SignpostingLink[] = [mocklink, mocklink2];
+
+    service.getLinks(uuid).subscribe((links) => {
+      result = links;
+    });
+
+    tick();
+
+    expect(result).toEqual(expectedResult);
+    expect(halServiceSpy.getRootHref).toHaveBeenCalled();
+    expect(restServiceSpy.get).toHaveBeenCalledWith(`${baseUrl}/signposting/links/${uuid}`);
+  }));
+
+  it('should handle error and return an empty array', fakeAsync(() => {
+    const uuid = '123';
+    const baseUrl = 'http://localhost:8080';
+
+    halServiceSpy.getRootHref.and.returnValue(`${baseUrl}/api`);
+
+    restServiceSpy.get.and.returnValue(of(mockErrResponse));
+
+    let result: any;
+
+    service.getLinks(uuid).subscribe((data) => {
+      result = data;
+    });
+
+    tick();
+
+    expect(result).toEqual([]);
+    expect(halServiceSpy.getRootHref).toHaveBeenCalled();
+    expect(restServiceSpy.get).toHaveBeenCalledWith(`${baseUrl}/signposting/links/${uuid}`);
+  }));
+});

src/app/core/data/signposting-data.service.ts

@@ -0,0 +1,38 @@
+import { Injectable } from '@angular/core';
+
+import { catchError, map } from 'rxjs/operators';
+import { Observable, of as observableOf } from 'rxjs';
+
+import { DspaceRestService } from '../dspace-rest/dspace-rest.service';
+import { HALEndpointService } from '../shared/hal-endpoint.service';
+import { RawRestResponse } from '../dspace-rest/raw-rest-response.model';
+import { SignpostingLink } from './signposting-links.model';
+
+/**
+ * Service responsible for handling requests related to the Signposting endpoint
+ */
+@Injectable({
+  providedIn: 'root'
+})
+export class SignpostingDataService {
+
+  constructor(private restService: DspaceRestService, protected halService: HALEndpointService) {
+  }
+
+  /**
+   * Retrieve the list of signposting links related to the given resource's id
+   *
+   * @param uuid
+   */
+  getLinks(uuid: string): Observable<SignpostingLink[]> {
+    const baseUrl = this.halService.getRootHref().replace('/api', '');
+
+    return this.restService.get(`${baseUrl}/signposting/links/${uuid}`).pipe(
+      catchError((err) => {
+        return observableOf([]);
+      }),
+      map((res: RawRestResponse) => res.statusCode === 200 ? res.payload as SignpostingLink[] : [])
+    );
+  }
+
+}

src/app/core/data/signposting-links.model.ts

@@ -0,0 +1,8 @@
+/**
+ * Represents the link object received by the signposting endpoint
+ */
+export interface SignpostingLink {
+    href?: string,
+    rel?: string,
+    type?: string
+}

src/app/core/services/server-hard-redirect.service.ts

@@ -46,6 +46,7 @@ export class ServerHardRedirectService extends HardRedirectService {
       }
 
       console.log(`Redirecting from ${this.req.url} to ${url} with ${status}`);
+
       this.res.redirect(status, url);
       this.res.end();
       // I haven't found a way to correctly stop Angular rendering.