title: Prevent DataView retrieving old data after it has been updated
body: <p>I've been having some problems with DataView that always retrieve the old data set. Even though the page has been re-loaded, IDataProvider has never been updated into the current state of the database. Here is how my IDataProvider looks like : </p>
  
  <pre><code>   private class MyDataProvider implements IDataProvider&lt;Item&gt; {
  
      private List&lt;Item&gt; list;
  
      private List&lt;Item&gt; getData() {
          if(list == null) {
              list = projectLogic.getItems();
              Collections.reverse(list);
          }
          return list;
      }
  
  
      @Override
      public Iterator&lt;Item&gt; iterator(int first, int count){
          return getData().subList(first, first + count).iterator();
      }
  
      @Override
      public int size(){
          return getData().size();
      }
  
      @Override
      public IModel&lt;Item&gt; model(Item object){
          return new DetachableItemModel(object);
      }
  
      /**
       * Detaches model after use. This is generally used to null out transient references that can be re-attached later. 
       */
      @Override
      public void detach(){
          list = null;
      }
  
  }
  </code></pre>
  
  <p>detach() is already set the list into null but why does this not affect the provider in my dataview?</p>