title: filter an async Table in Angular
body: <p>My Data is coming from an database (firestore) and I would like to use them in an async table. I use angular2-datatable for none async Data. My approach to use it in a async way does show me the table with the correct data but I cant use sorting on it.</p>
  
  <pre><code>&lt;table class="table table-striped" 
         [mfData]="users | async | dataFilter : filterQuery" 
          #mf="mfDataTable" 
          [mfRowsOnPage]="10" 
          [(mfSortBy)]="timestamp" 
          [(mfSortOrder)]="desc"&gt;
  &lt;/table&gt;
  </code></pre>
  
  <p>So my question. 
  1) Can I acutally use the sorting with async data and 2) What are am I doing wrong?</p>
  
  <p>example data:</p>
  
  <pre><code>{
    "1": {
      "id": 1,
      "timestamp": XXX
    },
    "2": {
      "id": 2,
      "timestamp": XXX
    },
    "3": {
      "id": 3,
      "timestamp": XXX
    }
  }
  </code></pre>