com.gwtplatform.mvp.client.proxy

Class NotifyingAsyncCallback<T>

java.lang.Object

com.gwtplatform.mvp.client.proxy.NotifyingAsyncCallback<T>

Type Parameters:

T - The type of the return value. See AsyncCallback.

All Implemented Interfaces:

AsyncCallback<T>

public abstract class NotifyingAsyncCallback<T>
extends Object
implements AsyncCallback<T>

An implementation of AsyncCallback that sends events on the EventBus whenever an async call starts, succeeds, or fails. The events fired are AsyncCallStartEvent, AsyncCallSucceedEvent, AsyncCallFailEvent.

So the way to use NotifyingAsyncCallback is the following:

   NotifyingAsyncCallback callback = new NotifyingAsyncCallback(eventBus) { ... };
   callback.prepare();
   someRpcMethod(callback);
   callback.checkLoading();
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NotifyingAsyncCallback.State This enum indicates the state of the notifying async callback.

Constructor Summary

Constructors

Constructor and Description
NotifyingAsyncCallback(EventBus eventBus)

Method Summary

Methods

Modifier and Type	Method and Description
void	checkLoading() This method is used to indicate that the async callback is currently loading.
protected void	failure(Throwable caught) This method is called whenever the asynchronous call returns with a failure.
void	onFailure(Throwable caught)
void	onSuccess(T result)
void	prepare() This method is used to place that the async callback in its INITIALIZED stated.
protected abstract void	success(T result) This method is called whenever the asynchronous call returns successfully.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NotifyingAsyncCallback

public NotifyingAsyncCallback(EventBus eventBus)

Method Detail

onFailure

public final void onFailure(Throwable caught)

Specified by:

onFailure in interface AsyncCallback<T>

onSuccess

public final void onSuccess(T result)

Specified by:

onSuccess in interface AsyncCallback<T>

prepare

public void prepare()

This method is used to place that the async callback in its INITIALIZED stated. It should be call prior to invoking any RPC that takes this callback as a parameter. See NotifyingAsyncCallback for usage.

checkLoading

public void checkLoading()

This method is used to indicate that the async callback is currently loading. It will not do anything if the call is already finished (i.e. in the case of an immediate failure or success). See NotifyingAsyncCallback for usage.

success

protected abstract void success(T result)

This method is called whenever the asynchronous call returns successfully.

Parameters:

result - the return value of the remote produced call.

failure

protected void failure(Throwable caught)

This method is called whenever the asynchronous call returns with a failure. Override this method if you want to perform clean-up operation when an async call fails. The default implementation is empty.

Parameters:

caught - failure encountered while executing a remote procedure call.