title: Populating OnDemandGrid with custom Dojo widget using Solr and JsonRest
body: <p>I have an OnDemandGrid with one column that I want to populate with a custom Dojo widget I built. The data used to populate each of these widgets comes from a Solr query. Since I am expecting possibly thousands of search results, I need to use a JsonRest object to make the queries and handle pagination. Here's what I have so far:</p>
  
  <p>The store:</p>
  
  <pre><code>var store = new JsonRest ({
      target: "/solr/json/response",
  });
  </code></pre>
  
  <p>Creating the grid:</p>
  
  <pre><code>var grid = new (declare([OnDemandGrid, Pagination])) ({
      store: store,
      getBeforePut: false,
      columns: [
          {
               label: "Test",
               field: "first",
               renderCell: myRenderFunction //To render the custom widget
          }
      ]
  }, "grid");
  
  grid.startup();
  </code></pre>
  
  <p>myRenderFunction:</p>
  
  <pre><code>var myRenderFunction = function(object, data, cell) {
  
      var widget = new MyCustomWidget({
          doc: object,
          foo: bar
      }, cell.appendChild(document.createElement("div"));
  
      widget.startup();
      return widget;
  }
  </code></pre>
  
  <p>Sample Solr response, in JSON form:</p>
  
  <pre><code>{
      "response":{
          "docs":[
              {
                  "foo": "Hello",
                  "bar": "World"
              },
              {
                  "foo": "Easy as",
                  "bar": "ABC"
              },
              {
                  "foo": "Simple as",
                  "bar": "Do re mi"
              }
          ]
      },
      "highlighting": { ... },
      "numFound": "74",
      "start": 0
  }
  </code></pre>
  
  <p>I have followed a few examples online demonstrating how to do this using JsonRest and any of the dgrid flavors (and they all worked), but when I try to render the widget to the grid nothing shows up and I get a <code>TypeError: transform(...) is null</code>.</p>
  
  <p>Is there any reason why I can't render my widget to the grid?</p>