/*******************************************************************************
 * Copyright (c) 2012-2015 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.websocket.rest;

import org.eclipse.che.ide.commons.exception.UnmarshallerException;
import org.eclipse.che.ide.websocket.Message;

/**
 * Deserializer for the body of the {@link Message}.
 * <p/>
 * By the contract:
 * <code>getPayload()</code> should never return <code>null</code> (should be initialized in impl's constructor
 * and return the same object (with different content) before and after <code>unmarshal()</code>.
 *
 * @param <T>
 * @author <a href="mailto:azatsarynnyy@exoplatfrom.com">Artem Zatsarynnyy</a>
 */
public interface Unmarshallable<T> {
    /**
     * Prepares an object from the incoming {@link Message}.
     *
     * @param response
     *         {@link Message}
     */
    void unmarshal(Message response) throws UnmarshallerException;

    /**
     * The content of the returned object normally differs before and
     * after <code>unmarshall()</code> but by the contract it should never be <code>null</code>.
     *
     * @return an object deserialized from the {@link Message}
     */
    T getPayload();
}