com.gwtplatform.dispatch.client.DefaultCallbackDispatchRequest Maven / Gradle / Ivy
/**
* Copyright 2011 ArcBees Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.gwtplatform.dispatch.client;
import com.google.gwt.user.client.rpc.AsyncCallback;
/**
* An implementation of {@link CallbackDispatchRequest} that should be used by
* {@link com.gwtplatform.dispatch.client.actionhandler.ClientActionHandler}s that
* make asynchronous calls that do not return a {@link com.google.gwt.http.client.Request}.
*
* {@link #isPending()} will return true until either {@link #onSuccess(Object)} or
* {@link #onFailure} is called.
*
* Calling {@link #cancel()} will prevent the {@link #onSuccess(Object)} and
* {@link #onFailure(Throwable)} from being forwarded to the code that requested the
* action handler be executed/undone.
*
* @param The type of the {@link AsyncCallback}.
* @author Brendan Doherty
*/
public class DefaultCallbackDispatchRequest implements CallbackDispatchRequest {
private boolean pending;
private final AsyncCallback callback;
/**
* Construct a {@link DefaultCallbackDispatchRequest}. See the class documentation
* for details.
*
* @param callback The resultCallback parameter passed to
* {@link com.gwtplatform.dispatch.client.actionhandler.ClientActionHandler#execute
* ClientActionHandler#execute()}
* or the callback parameter passed to
* {@link com.gwtplatform.dispatch.client.actionhandler.ClientActionHandler#undo
* ClientActionHandler#undo()}
*/
public DefaultCallbackDispatchRequest(AsyncCallback callback) {
this.callback = callback;
this.pending = true;
}
@Override
public void cancel() {
pending = false;
}
@Override
public boolean isPending() {
return pending;
}
@Override
public void onFailure(Throwable caught) {
if (pending) {
pending = false;
callback.onFailure(caught);
}
}
@Override
public void onSuccess(R result) {
if (pending) {
pending = false;
callback.onSuccess(result);
}
}
}