title: Iterating over records in an ExtJS store and filtering on a specific field
body: <p>I am iterating over records in a store as they come in like so:</p>
  
  <pre><code>Ext.create('Ext.data.Store', {
      model: 'Message',
      storeId: 'Staging',
      proxy: {
          type: 'memory',
          reader: {
              type: 'json'
          }
      },
      listeners: {
          add: function(store, records, index, eOpts){
              if (!Ext.data.StoreManager.lookup('Historical').isLoading()) {
  
                  this.each(function(item, index, count) {
                      if(item.notificationType === 'INBOX'){
                          // populate inbox store
                          // increment the unread inbox count
                          console.log('inbox');
                      } else if (item.notificationType === 'NOTIFICATION') {
                          // populate notifications store
                          // increment the unread notification count
                      }
                  });
  
                  // no historical data should be held in memory for performance
                  this.removeAll();
  
              }  
          }
      }   
  }); 
  </code></pre>
  
  <p>The <em>item.notificationType</em> property returns undefined.</p>
  
  <p>I have tried other properties but they also return undefined.</p>
  
  <p>I need to perform different actions when different types are encountered and thought this would do it!</p>
  
  <p>So the item is a record in the store which contains json in the structure as follows:</p>
  
  <pre><code>   {
        "source":"2",
        "target":"1416529",
        "sourceType":"USER",
        "redirectUrl":null,
        "message":"cow's go...",
        "id":606,
        "targetType":"TEAM",
        "messageType":"TIBRR_WALL_MESSAGE",
        "notificationType":"INBOX",
        "sentDate":1356599137173,
        "parameters":null,
        "targetId":"1416529",
        "sourceId":"2",
        "dispatched":true,
        "read":false,
        "readDate":null,
        "dispatchedDate":1356599137377
     }
  </code></pre>