package org.activityinfo.legacy.shared.command;
/*
* #%L
* ActivityInfo Server
* %%
* Copyright (C) 2009 - 2013 UNICEF
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program. If not, see
* <http://www.gnu.org/licenses/gpl-3.0.html>.
* #L%
*/
import org.activityinfo.legacy.shared.command.result.CommandResult;
import java.io.Serializable;
/**
* Marker interface for RPC commands.
* <p/>
* Rather than defining a method in the
* {@link org.activityinfo.legacy.shared.command.RemoteCommandService} interface for
* each server-side operation, we define a single
* {@link org.activityinfo.legacy.shared.command.RemoteCommandService#execute(String, java.util.List)}
* method which accepts objects that implement this marker interface.
* <p/>
* On the server, each Command class has a corresponding
* {@link org.activityinfo.server.command.handler.CommandHandler} class which
* carries out the operation.
* <p/>
* This approach is a bit of a riff on Aspect Oriented Programming (AOP),
* allowing us to handle all manners of cross-cutting concerns, such as
* batching, error handling, retrying, and failure on the client side (See
* {@link org.activityinfo.legacy.client.remote.MergingDispatcher}) and
* transactions, logging, and authentication on the server-side. (See
* {@link org.activityinfo.server.endpoint.gwtrpc.CommandServlet}).
*
* @param <T> The type of return type expected as a result
* @author Alex Bertram
*/
public interface Command<T extends CommandResult> extends Serializable {
}