Saturday, October 26, 2013

Re: What is the simplest way to show “loading indicator” during an RPC call in GWTP?

I found a cool solution, that is we have to use WidgetPresenter with PopupPanel (say LoadingPresenter). So in my Custom AsyncCall class, i need to fire loadingPresenter. It won't work if we use PopupPanel class inside AsyncCall, i don't understand why? but work if we use PopupPanel Presenter widget

public abstract class AsyncCall<T> implements AsyncCallback<T> {

    /** Call the service method using cb as the callback. */
    public AsyncCall()
        Utility.eventBus.fireEvent(new ShowLoadingEvent(true));

    public final void onFailure(Throwable caught) 
        Utility.eventBus.fireEvent(new ShowLoadingEvent(false));

    public final void onSuccess(T result) 
        Utility.eventBus.fireEvent(new ShowLoadingEvent(false));
    /** the failure method needed to be overwritte */   
    protected abstract void onCustomFailure(Throwable caught);  

    /** overwritte to do something with result */
    protected abstract void onCustomSuccess(T result); 


To make RPC Call, simple use this:

  private AsyncCall<GetDataResult> getDataCallback=new AsyncCall<GetDataResult>(){

        public void onCustomFailure(Throwable caught) {


        public void onCustomSuccess(GetVerbFromTripleResult result) {
             //show data here (it may take long time)


and then it run really smoothly.

On Saturday, October 26, 2013 8:21:57 PM UTC+11, Tom wrote:

I am using GWTP to build my webapp. Here is my problem. I have a customer page (CustPresenter). When that page is visited, it will call & load Data from Database.

It may take a while to load all data, so I want my current Browser locked so that the user can not click any things while data has not finished downloading yet.

So here is what I am thinking. I want to show a DialogBox right before I make the RPC call & hide it when the call finishes. Look at the below code:

public class CustPresenter extends      Presenter<CustPresenter.MyView, CustPresenter.MyProxy> {        private DialogBox loadingDialogBox=new DialogBox();        @Inject DispatchAsync dispatchAsync;        @Override      public void prepareFromRequest(PlaceRequest request){           super.prepareFromRequest(request); ;           GetData getDataAction=new GetData();           dispatchAsync.execute(getDataAction, getDataCallback);        }        private AsyncCallback<GetDataResult> getDataCallback=new AsyncCallback<GetDataResult>(){            @Override          public void onFailure(Throwable caught) {              loadingDialogBox.hide();          }            @Override          public void onSuccess(GetVerbFromTripleResult result) {               //show data here (it may take long time)               loadingDialogBox.hide();          }     };  }  

However, when runing, the dialogbox only shows up for 1 second & then disappears. Right After that all the UiBinder Guis show up on the Customer Page & user can click any buttons on the page while the data has not finished downloading yet. This is not a correct behavior.

I want to do something like this!2/a2581/1. As u can see, when u first time open that link, a loading panel popups & u can't click anything until all guis show up.

So, why do I have this problem?

How to fix it?

Or generally, What is the simplest way to show "loading indicator" during an RPC call in GWTP?

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