title: Encode specific fields from store in JSON
body: <p>Currently I can take a store, push it into an array, and encode it to a JSON object with this:</p>
  
  <pre><code>        var models = msgLogStore.getRange(),
              tmpArray = [];
  
          for (m = 0; m &lt; models.length; m++) {
              tmpArray.push(models[m].data);
          }
  
          var msgLogDataAsJson = Ext.JSON.encode(tmpArray);
  </code></pre>
  
  <p>But how would I go about only pushing specific fields?</p>