Bug fix preventing undesired recreation of poll-collection and poll-votes on poll change.

client/src/app/site/cinema/components/poll-collection/poll-collection.component.html

@@ -1,4 +1,4 @@
-<mat-card class="os-card" *ngFor="let poll of polls">
+<mat-card class="os-card" *ngFor="let poll of polls; trackBy: identifyPoll">
     <p class="subtitle-text">
         <a [routerLink]="getPollDetailLink(poll)" [state]="{ back: 'true' }">{{ getPollVoteTitle(poll) }}</a>
     </p>

client/src/app/site/cinema/components/poll-collection/poll-collection.component.ts

@@ -53,6 +53,10 @@ export class PollCollectionComponent extends BaseViewComponentDirective implemen
         );
     }
 
+    public identifyPoll(index: number, poll: ViewBasePoll): number {
+        return poll.id;
+    }
+
     public getPollVoteTitle(poll: ViewBasePoll): string {
         const contentObject = poll.getContentObject();
         const listTitle = contentObject.getListTitle();