Question: Assuming that data retrieves from DataStore using RPCproxy, populate to grid using ListStore upon opening the page. 

Then, there's a form to add an entity and after modification it will reflect the new list in GXT grid with the new added row.

How can reload the grid? I tried .reconfigure() method in Grid but didn't work.

Answer: 
grid.getStore().getLoader().load();

update:

First of all you must extract Grid before your Proxy, and the second thing is to change your RPC callback:

```

    public class PagingBeanModelGridExample extends LayoutContainer {  

    //put grid Class outside a method or declare it as a final on the begin of a method
    Grid grid = null;

    protected void onRender(Element parent, int index) {
        super.onRender(parent, index);

        RpcProxy> proxy = new RpcProxy>() {

            @Override
            public void load(Object loadConfig, final AsyncCallback> callback) {
                //modification here - look that callback is overriden not passed through!!
                service.getBeanPosts((PagingLoadConfig) loadConfig, new AsyncCallback>() {

                    public void onFailure(Throwable caught) {
                        callback.onFailure(caught);
                    }

                    public void onSuccess(PagingLoadResult result) {
                        callback.onSuccess(result);
                        //here you are reloading store
                        grid.getStore().getLoader().load();
                    }
                });
            }
        };

        // loader  
        final BasePagingLoader> loader = new BasePagingLoader>(proxy, new BeanModelReader());

        ListStore store = new ListStore(loader);
        List columns = new ArrayList();
        //...  
        ColumnModel cm = new ColumnModel(columns);

        grid = new Grid(store, cm);
        add(grid);

    }
} 
```
To display the new data to grid do you really need to reload the grid? 
You can create a new model object with the new data and add this to the ListStore.

Suppose you have a CommentModel which extends the BaseModel and a ListStore of Comment model commentStore.  

```
final ListStore<Commentmodel> commentStore = new ListStore<Commentmodel>();

//now call a rpc to load all available comments and add this to the commentStore.
commentService.getAllComment(new AsyncCallback<List<Commentmodel>>() {

   @Override
   public void onFailure(Throwable caught) {
    lbError.setText("data loading failure");

   }

   @Override
   public void onSuccess(List<Commentmodel> result) {
    commentStore.add(result);

   }
  }); 

```

`commentService` is an `AsyncService`.

Now if a user post a comment, just create a new `CommentModel` object with the new data

`CommentModel newData = new CommentModel('user name', 'message','date');`

And add this to the commentStore. 

`commentStore.add(newData);`

Hope this will serve you purpose.

But if you really need to reload the whole set of data, call the service again. In the `onSuccess` method first clear the commentStore then add result. Remember this is more more time consuming that the 1st approach.