UndoCommand.java

/*
 * 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.rpc.client.interceptor;

import com.google.gwt.user.client.rpc.AsyncCallback;
import com.gwtplatform.dispatch.shared.DispatchRequest;

/**
 * The interface that {@link RpcInterceptor}s use to send the action to undo to the server.
 *
 * @param <A> The action type.
 * @param <R> The result type.
 */
public interface UndoCommand<A, R> {
    /**
     * Undo an action.
     *
     * @param action   The action to undo.
     * @param result   The result of the action to undo.
     * @param callback A callback that will be invoked once the action has been undone, successfully or not.
     * @return A {@link com.gwtplatform.dispatch.shared.DispatchRequest} object representing the request,
     *           it should never be {@code null}.
     */
    DispatchRequest undo(A action, R result, AsyncCallback<Void> callback);
}