Add custom dimension (handle) to pageTrack of matomo

This extends/overrides the pageTrack/eventTrack methods of angulartics
matomo plugin and hooks into the event tracking (view-tracker.component)
that's there for DSpace internal statistics.

Author: kosarko

src/app/statistics/angulartics/dspace/view-tracker.component.ts

@@ -36,12 +36,14 @@ export class ViewTrackerComponent implements OnInit, OnDestroy {
     this.sub = this.referrerService.getReferrer()
       .pipe(take(1))
       .subscribe((referrer: string) => {
+        let dc_identifier  = this.object.firstMetadataValue("dc.identifier.uri");
         this.angulartics2.eventTrack.next({
           action: 'page_view',
           properties: {
             object: this.object,
             referrer,
             category: 'page_view',
+            dc_identifier: dc_identifier
           },
         });
       });

src/config/default-app-config.ts

@@ -433,6 +433,7 @@ export class DefaultAppConfig implements AppConfig {
   // Matomo configuration
   matomo: MatomoConfig = {
     hostUrl: 'http://localhost:8135/',
-    siteId: '1'
+    siteId: '1',
+    dimensionId: 1
   };
 }

src/config/matomo-config.ts

@@ -8,4 +8,6 @@ export class MatomoConfig implements Config {
   public hostUrl: string;
 
   public siteId: string;
+
+  public dimensionId: Number;
 }

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

@@ -102,6 +102,21 @@ export class BrowserInitService extends InitService {
       this.initRouteListeners();
       this.themeService.listenForThemeChanges(true);
       this.trackAuthTokenExpiration();
+      // ideally we'd add the custom dimension to the 'trackPageView' action only, but don't have that information
+      // in pageTrack context. So we add it to page_view events, and remove it after the page view.
+      // page_view events are fired via view-track.component, and exposes dc.identifier.uri via properties
+      this.angulartics2Matomo.eventTrack = function (action, properties? : any) {
+        if (action === 'page_view') {
+          if (properties.dc_identifier) {
+            (window as any)._paq.push(['setCustomDimension', environment.matomo.dimensionId, properties.dc_identifier]);
+          }
+        }
+      };
+      let pageTrack = this.angulartics2Matomo.pageTrack;
+      this.angulartics2Matomo.pageTrack = function (path: string) {
+        pageTrack.call(this, path);
+        (window as any)._paq.push(['deleteCustomDimension', environment.matomo.dimensionId]);
+      };
       this.angulartics2Matomo.startTracking();
 
       this.initKlaro();