[CST-5729] implemented functionality to add link tags in head html section when on item page

server.ts

@@ -180,14 +180,14 @@ export function app() {
     changeOrigin: true
   }));
 
-    /**
+  /**
    * Proxy the linksets
    */
-    router.use('/linksets**', createProxyMiddleware({
+  router.use('/linkset**', createProxyMiddleware({
-      target: `${environment.rest.baseUrl}/linksets`,
+    target: `${environment.rest.baseUrl}/signposting/linksets`,
-      pathRewrite: path => path.replace(environment.ui.nameSpace, '/'),
+    pathRewrite: path => path.replace(environment.ui.nameSpace, '/'),
-      changeOrigin: true
+    changeOrigin: true
-    }));
+  }));
 
   /**
    * Checks if the rateLimiter property is present

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

@@ -0,0 +1,16 @@
+import { TestBed } from '@angular/core/testing';
+
+import { SignpostingDataService } from './signposting-data.service';
+
+describe('SignpostingDataService', () => {
+  let service: SignpostingDataService;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(SignpostingDataService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+});

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

@@ -0,0 +1,52 @@
+import { Injectable } from '@angular/core';
+import { DspaceRestService } from '../dspace-rest/dspace-rest.service';
+// import { HttpHeaders, HttpResponse } from '@angular/common/http';
+import { catchError, map } from 'rxjs/operators';
+// import { throwError } from 'rxjs';
+import { Observable, of as observableOf } from 'rxjs';
+import { HALEndpointService } from '../shared/hal-endpoint.service';
+import { RawRestResponse } from '../dspace-rest/raw-rest-response.model';
+import { HttpHeaders } from '@angular/common/http';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class SignpostingDataService {
+
+  constructor(private restService: DspaceRestService, protected halService: HALEndpointService) { }
+
+  getLinks(uuid: string): Observable<any> {
+    const url = this.halService.getRootHref().split('/');
+    const baseUrl = `${url[0]}//${url[2]}/${url[3]}`;
+
+    return this.restService.get(`${baseUrl}/signposting/links/${uuid}`).pipe(
+      catchError((err ) => {
+        console.error(err);
+        return observableOf(false);
+      }),
+      map((res: RawRestResponse) => res)
+    );
+  }
+
+  getLinksets(uuid: string): Observable<any> {
+    const url = this.halService.getRootHref().split('/');
+    const baseUrl = `${url[0]}//${url[2]}/${url[3]}`;
+
+    const requestOptions = {
+      observe: 'response' as any,
+      headers: new HttpHeaders({
+        'accept': 'application/linkset',
+        'Content-Type': 'application/linkset'
+      }),
+      responseType: 'text'
+    } as any;
+
+    return this.restService.getWithHeaders(`${baseUrl}/signposting/linksets/${uuid}`, requestOptions).pipe(
+      catchError((err ) => {
+        console.error(err);
+        return observableOf(false);
+      }),
+      map((res: RawRestResponse) => res)
+    );
+  }
+}

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

@@ -0,0 +1,5 @@
+export interface SignpostingDataLink {
+    href: string,
+    rel: string,
+    type: string
+}

src/app/core/dspace-rest/dspace-rest.service.ts

@@ -1,4 +1,4 @@
-import { Observable, throwError as observableThrowError } from 'rxjs';
+import { Observable, throwError as observableThrowError, throwError } from 'rxjs';
 import { catchError, map } from 'rxjs/operators';
 import { Injectable } from '@angular/core';
 import { HttpClient, HttpHeaders, HttpParams, HttpResponse } from '@angular/common/http';
@@ -58,6 +58,19 @@ export class DspaceRestService {
       }));
   }
 
+  getWithHeaders(absoluteURL: string, reqOptions: any): Observable<any> {
+    const requestOptions = reqOptions;
+
+    return this.http.get(absoluteURL, requestOptions).pipe(
+      map((res) => ({
+        payload: res
+      })),
+      catchError((err) => {
+        console.log('Error: ', err);
+        return throwError(() => new Error(err.error));
+      }));
+  }
+
   /**
    * Performs a request to the REST API.
    *

src/app/core/metadata-item/metadata-item.service.spec.ts

@@ -1,16 +0,0 @@
-import { TestBed } from '@angular/core/testing';
-
-import { MetadataItemService } from './metadata-item.service';
-
-describe('MetadataItemService', () => {
-  let service: MetadataItemService;
-
-  beforeEach(() => {
-    TestBed.configureTestingModule({});
-    service = TestBed.inject(MetadataItemService);
-  });
-
-  it('should be created', () => {
-    expect(service).toBeTruthy();
-  });
-});

src/app/core/metadata-item/metadata-item.service.ts

@@ -1,70 +0,0 @@
-import { Inject, Injectable } from '@angular/core';
-import { MetadataService } from '../metadata/metadata.service';
-import { ActivatedRoute, NavigationEnd, Event as NavigationEvent, NavigationStart, Router } from '@angular/router';
-import { TranslateService } from '@ngx-translate/core';
-import { Meta, Title } from '@angular/platform-browser';
-import { DSONameService } from '../breadcrumbs/dso-name.service';
-import { BundleDataService } from '../data/bundle-data.service';
-import { BitstreamDataService } from '../data/bitstream-data.service';
-import { BitstreamFormatDataService } from '../data/bitstream-format-data.service';
-import { RootDataService } from '../data/root-data.service';
-import { CoreState } from '../core-state.model';
-import { Store } from '@ngrx/store';
-import { HardRedirectService } from '../services/hard-redirect.service';
-import { APP_CONFIG, AppConfig } from 'src/config/app-config.interface';
-import { AuthorizationDataService } from '../data/feature-authorization/authorization-data.service';
-import { filter, map, switchMap, take, mergeMap } from 'rxjs/operators';
-import { DOCUMENT } from '@angular/common';
-
-@Injectable({
-  providedIn: 'root'
-})
-export class MetadataItemService extends MetadataService {
-
-  constructor(
-    private router1: ActivatedRoute,
-    router: Router,
-    translate: TranslateService,
-    meta: Meta,
-    title: Title,
-    dsoNameService: DSONameService,
-    bundleDataService: BundleDataService,
-    bitstreamDataService: BitstreamDataService,
-    bitstreamFormatDataService: BitstreamFormatDataService,
-    rootService: RootDataService,
-    store: Store<CoreState>,
-    hardRedirectService: HardRedirectService,
-    @Inject(APP_CONFIG) appConfig: AppConfig,
-    authorizationService: AuthorizationDataService,
-    @Inject(DOCUMENT) private document: Document
-  ) { 
-    super(router, translate, meta, title, dsoNameService, bundleDataService, bitstreamDataService, bitstreamFormatDataService, rootService, store, hardRedirectService, appConfig, authorizationService);
-  }
-
-  public checkCurrentRoute(){
-
-    console.log(this.router);
-
-    this.router1.url.subscribe(url => {
-      console.log(url);
-      console.log(url[0].path);
-    });
-
-    // this.router.events.subscribe((event: NavigationEvent) => {
-    //   if(event instanceof NavigationStart) {
-    //     if(event.url.startsWith('/entities')){
-    //       console.log('We are on ENTITIES!');
-    //     }
-    //   }
-    // });
-  }
-
-  setLinkTag(){
-    this.clearMetaTags();
-
-    let link: HTMLLinkElement = this.document.createElement('link');
-    link.setAttribute('rel', '');
-    link.setAttribute('href', '');
-    this.document.head.appendChild(link);
-  }
-}

src/app/core/metadata/metadata.service.ts

@@ -45,6 +45,7 @@ import { CoreState } from '../core-state.model';
 import { AuthorizationDataService } from '../data/feature-authorization/authorization-data.service';
 import { getDownloadableBitstream } from '../shared/bitstream.operators';
 import { APP_CONFIG, AppConfig } from '../../../config/app-config.interface';
+import { SignpostingDataService } from '../data/signposting-data.service';
 
 /**
  * The base selector function to select the metaTag section in the store
@@ -96,7 +97,8 @@ export class MetadataService {
     private store: Store<CoreState>,
     private hardRedirectService: HardRedirectService,
     @Inject(APP_CONFIG) private appConfig: AppConfig,
-    private authorizationService: AuthorizationDataService
+    private authorizationService: AuthorizationDataService,
+    private signpostginDataService: SignpostingDataService
   ) {
   }
 
@@ -138,7 +140,7 @@ export class MetadataService {
     }
   }
 
-  private getCurrentRoute(route: ActivatedRoute): ActivatedRoute {
+  public getCurrentRoute(route: ActivatedRoute): ActivatedRoute {
     while (route.firstChild) {
       route = route.firstChild;
     }
@@ -162,6 +164,8 @@ export class MetadataService {
     this.setCitationAbstractUrlTag();
     this.setCitationPdfUrlTag();
     this.setCitationPublisherTag();
+    this.setSignpostingLinks();
+    this.setSignpostingLinksets();
 
     if (this.isDissertation()) {
       this.setCitationDissertationNameTag();
@@ -184,6 +188,45 @@ export class MetadataService {
 
   }
 
+  /**
+   * Add <link name="title" ... >  to the <head>
+   */
+  private setSignpostingLinks() {
+    if (this.currentObject.value instanceof Item){
+      const value = this.signpostginDataService.getLinks(this.currentObject.getValue().id);
+      value.subscribe(links => {
+        links.payload.forEach(link => {
+          this.setLinkTag(link.href, link.rel, link.type);
+        });
+      });
+    }
+  }
+
+  setLinkTag(href: string, rel: string, type: string){
+    let link: HTMLLinkElement = document.createElement('link');
+    link.href = href;
+    link.rel = rel;
+    link.type = type;
+    document.head.appendChild(link);
+    console.log(link);
+  }
+
+  private setSignpostingLinksets() {
+    if (this.currentObject.value instanceof Item){
+      const value = this.signpostginDataService.getLinksets(this.currentObject.getValue().id);
+      value.subscribe(linksets => {
+        this.setLinkAttribute(linksets);
+      });
+    }
+  }
+
+  setLinkAttribute(linksets){
+    console.log('ANDREA', linksets);
+    const linkAttribute = `Link: ${linksets.payload.body}`;
+    const textNode = document.createTextNode(linkAttribute);
+    document.head.appendChild(textNode);
+  }
+
   /**
    * Add <meta name="title" ... >  to the <head>
    */
@@ -363,15 +406,6 @@ export class MetadataService {
     }
   }
 
-  /**
- * Add <meta name="link" ... >  to the <head>
- */
-  // private setLinkTag(): void {
-  //   const value = this.getMetaTagValue('dc.link');
-  //   this.meta.addTag({ name: 'Link', content: value });
-  //   this.addMetaTag('Link', value);
-  // }
-
   getBitLinkIfDownloadable(bitstream: Bitstream, bitstreamRd: RemoteData<PaginatedList<Bitstream>>): Observable<string> {
     return observableOf(bitstream).pipe(
       getDownloadableBitstream(this.authorizationService),

src/app/init.service.ts

@@ -24,7 +24,6 @@ import { isAuthenticationBlocking } from './core/auth/selectors';
 import { distinctUntilChanged, find } from 'rxjs/operators';
 import { Observable } from 'rxjs';
 import { MenuService } from './shared/menu/menu.service';
-import { MetadataItemService } from './core/metadata-item/metadata-item.service';
 
 /**
  * Performs the initialization of the app.
@@ -51,7 +50,6 @@ export abstract class InitService {
     protected localeService: LocaleService,
     protected angulartics2DSpace: Angulartics2DSpace,
     protected metadata: MetadataService,
-    protected metadataItem: MetadataItemService,
     protected breadcrumbsService: BreadcrumbsService,
     protected themeService: ThemeService,
     protected menuService: MenuService,
@@ -190,7 +188,7 @@ export abstract class InitService {
     this.breadcrumbsService.listenForRouteChanges();
     this.themeService.listenForRouteChanges();
     this.menuService.listenForRouteChanges();
-    this.metadataItem.checkCurrentRoute();
+    // this.metadataItem.checkCurrentRoute();
   }
 
   /**

src/modules/app/browser-init.service.ts

@@ -32,7 +32,6 @@ import { logStartupMessage } from '../../../startup-message';
 import { MenuService } from '../../app/shared/menu/menu.service';
 import { RootDataService } from '../../app/core/data/root-data.service';
 import { firstValueFrom, Subscription } from 'rxjs';
-import { MetadataItemService } from 'src/app/core/metadata-item/metadata-item.service';
 
 /**
  * Performs client-side initialization.
@@ -52,7 +51,6 @@ export class BrowserInitService extends InitService {
     protected angulartics2DSpace: Angulartics2DSpace,
     protected googleAnalyticsService: GoogleAnalyticsService,
     protected metadata: MetadataService,
-    protected metadataItem: MetadataItemService,
     protected breadcrumbsService: BreadcrumbsService,
     protected klaroService: KlaroService,
     protected authService: AuthService,
@@ -68,7 +66,6 @@ export class BrowserInitService extends InitService {
       localeService,
       angulartics2DSpace,
       metadata,
-      metadataItem,
       breadcrumbsService,
       themeService,
       menuService,

src/modules/app/server-init.service.ts

@@ -21,7 +21,6 @@ import { BreadcrumbsService } from '../../app/breadcrumbs/breadcrumbs.service';
 import { ThemeService } from '../../app/shared/theme-support/theme.service';
 import { take } from 'rxjs/operators';
 import { MenuService } from '../../app/shared/menu/menu.service';
-import { MetadataItemService } from 'src/app/core/metadata-item/metadata-item.service';
 
 /**
  * Performs server-side initialization.
@@ -37,7 +36,6 @@ export class ServerInitService extends InitService {
     protected localeService: LocaleService,
     protected angulartics2DSpace: Angulartics2DSpace,
     protected metadata: MetadataService,
-    protected metadataItem: MetadataItemService,
     protected breadcrumbsService: BreadcrumbsService,
     protected themeService: ThemeService,
     protected menuService: MenuService
@@ -50,7 +48,6 @@ export class ServerInitService extends InitService {
       localeService,
       angulartics2DSpace,
       metadata,
-      metadataItem,
       breadcrumbsService,
       themeService,
       menuService,