title: How to change the sort oder of a list in SAPUI5 by user event?
body: <p>In my masterview of an split-app I have a list with purchase order items. Initially, the list is ordered descending by the purchase order numbers. I achieved this by defining a sorter in the xml-View declaratively:</p>
  
  
  
  <pre class="lang-html prettyprint-override"><code>&lt;List
      id="listBestellungen"
      noDataText="{i18n&gt;masterListNoDataText}"
      growing="true"
      growingScrollToLoad="true"
      updateFinished="onUpdateFinished"
      selectionChange="onSelectionChange"
      items="{
          path: '/PO_HeadInfoSet',
          sorter: {
              path: 'POHI_Ebeln',
              descending: true
          }
                      }"
                      mode="SingleSelectMaster"
                      &gt;
  ...
  </code></pre>
  
  
  
  <p>Then I have a SortSelect-Button in the footer with the press-Event "onSorting".</p>
  
  <p>The onSorting function looks like this:</p>
  
  <pre><code>onSorting: function(oEvent) {
          var oView = this.getView();
          var oList = oView.byId("listBestellungen");
          var oBinding = oList.getBinding("items");
  
          var SORTKEY = "POHI_Ebeln";
          var DESCENDING = false;
          var GROUP = false;
          var aSorter = [];
  
          aSorter.push(new sap.ui.model.Sorter(SORTKEY, DESCENDING, GROUP));
          oBinding.sort(aSorter);
      }
  </code></pre>
  
  <p>The onSorting function is invoked when I click on the sorting button. Also I can see, that the sorting direction is changed in the binding.</p>
  
  <p>But why or how do I change the sorting of the list in the UI?</p>
  
  <p>Kind regards</p>
  
  <p>Michael</p>