title: How to make pagination with unclear values?
body: <p>I have a list of rooms (users) to chat which I get via socket.io.</p>
  <p>And I want to paginate this list using <strong>ngb-pagination</strong>.</p>
  <p>But in response I get a bunch of errors:</p>
  <p>How to fix it?</p>
  <blockquote>
  <p>Parser Error: Cannot have a pipe in an action expression at column 11
  in [(rooms$ | async)?.meta?.currentPage=$event]</p>
  </blockquote>
  <p><strong>html:</strong></p>
  <pre><code>&lt;ngb-pagination [collectionSize]=&quot;(rooms$ | async)?.meta?.totalItems&quot; [(page)]=&quot;(rooms$ | async)?.meta?.currentPage&quot;
      [pageSize]=&quot;(rooms$ | async)?.meta?.itemsPerPage&quot; (pageChange)=&quot;onPaginateRooms($event)&quot;&gt;
  &lt;/ngb-pagination&gt;
  </code></pre>
  <p><strong>ts:</strong></p>
  <pre><code>export declare class PageEvent {
    pageIndex: number;
    previousPageIndex?: number;
    pageSize: number;
    length: number;
  }
  
  rooms$: Observable&lt;RoomPaginateI&gt; = this.chatService.getMyRooms();
  
  ngOnInit() {
    this.chatService.emitPaginateRooms(10, 0);
  }
  
  ngAfterViewInit() {
    this.chatService.emitPaginateRooms(10, 0);
  }
  
  onPaginateRooms(pageEvent: PageEvent) {
    this.chatService.emitPaginateRooms(pageEvent.pageSize, pageEvent.pageIndex);
  }
  </code></pre>