title: DOJO 1.8. FilteringSelect in DataGrid fed by FileItemReadStore is not working
body: <p>I'm struggeling with DOJO 1.8 and Datagrid. I would like to put a filteringSelect into a Datagrid cell. The widget should be fed by a Store. The store is fed by an AJAX request and works find. Also the select widget shows up, but it is empty. There's neither a value nor an option to see in the browser:</p>
  
  <p>The Code for the Store:</p>
  
  <pre><code>     // AJAX REQUEST TO GET PROJECTS AND SAVE AS STORE
   require(['dojo/request', 'dojo/data/ItemFileReadStore'], function(request, ItemFileReadStore){
      request('project/json/getprojects', {
          handleAs: 'json'
      }).then(function(json){
         var projectStore = new ItemFileReadStore({data: {'identifier':'id', 'label':'label', 'items': json}});   
      });
  </code></pre>
  
  <p>The JSON I retrieve looks like this:</p>
  
  <pre><code>[{"id":2,"name":"Bilder-App","customer":"Company A","label":"Company A &gt;&gt; Bilder-App"},{"id":8,"name":"Zeiterfassung","customer":"Company B","label":"Company B &gt;&gt; Zeiterfassung"}]
  </code></pre>
  
  <p>The goal is that the select-box shows the "label" field visually and saves "id" to the store/grid.</p>
  
  <p>Here's the code of the grid_layout for the cell:</p>
  
  <pre><code>{field: "project_id", name: "Kunde/Projekt", type: dojox.grid.cells._Widget, widgetClass: dijit.form.Select, widgetProps: {store: projectStore,  searchAttr: "label"} },
  </code></pre>
  
  <p>Is anyone able to help me with that?</p>
  
  <p>MANY THANKS! </p>
  
  <p>AFX</p>
  
  <hr>
  
  <p>Here is the working formatter:</p>
  
  <pre><code>  // PROJECT-ID FORMATTER
       function formatProjectId(value, index){ 
              var item =  projectStore.get(value);
              var label = item['label'];  
               return label; 
        }     
  </code></pre>
  
  <p>However, there's one slight problem: Right when I selected the  item in the select box it shows the id in the field. When I leave the field it gets formatted correctly.</p>
  
  <p>Does anyone know how to solve this?</p>