net.sf.eBus.client.CancelRequestCallback Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of core Show documentation
The newest version!
//
// Copyright 2016 Charles W. Rapp
//
// 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 net.sf.eBus.client;

/**
 * A class implementing {@code EReplier} is not required to
 * override {@link EReplier#cancelRequest(EReplyFeed.ERequest, boolean)}.
 * Instead, a Java lambda expression for
 * {@code CancelRequestCallback} may be passed to
 * {@link EReplyFeed.Builder#cancelRequestCallback(CancelRequestCallback)}
 * and the lambda expression code will be executed when a
 * request is canceled.
 *
 * @see EReplyFeed.Builder#cancelRequestCallback(CancelRequestCallback)
 *
 * @author Charles W. Rapp
 */

@FunctionalInterface
public interface CancelRequestCallback
{
//---------------------------------------------------------------
// Member methods.
//

    /**
     * With eBus release 5.6.0 a second, parameter is added:
     * {@code mayRespond}. If {@code true} the replier accepts
     * the cancel request, the replier should respond with an
     * appropriate
     * {@link net.sf.eBus.messages.EReplyMessage reply message}
     * (note that a new
     * {@link net.sf.eBus.messages.EReplyMessage.ReplyStatus}
     * has been added: {@code CANCELED}). If the replier rejects
     * this cancel request then it may respond with
     * a {@code EReplyMessage} with a status of
     * {@code CANCEL_REJECT} and a reason for the reject.
     * does nothing and continues to
     * work the request.
     * 
     * if {@code mayRespond} is {@code false} then this is a
     * unilateral request cancellation. The request is shut down
     * and no further replies will be accepted. However,
     * in-flight replies posted prior to cancellation
     * may still be delivered.
     * 
     * 
     * {@link EReplyFeed.ERequest request} matches the
     * replier's open and advertised {@link EReplyFeed feed}. The
     * associated {@code EReplyFeed} may be retrieved by calling
     * {@link EReplyFeed.ERequest#replier()}.
     * 
     * @param request cancel this request.
     * @param mayRespond set to {@code true} if replier is
     * allowed to respond to the cancel request. This allows the
     * replier to accept or reject the request cancellation.
     */
    void call(EReplyFeed.ERequest request,
              boolean mayRespond);
} // end of interface CancelRequestCallback