/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.classic;
import java.io.Serializable;
import org.hibernate.CallbackException;
import org.hibernate.Session;
/**
* Provides callbacks from the <tt>Session</tt> to the persistent object.
* Persistent classes <b>may</b> implement this interface but they are not
* required to.<br>
* <br>
* <b>onSave:</b> called just before the object is saved<br>
* <b>onUpdate:</b> called just before an object is updated,
* ie. when <tt>Session.update()</tt> is called<br>
* <b>onDelete:</b> called just before an object is deleted<br>
* <b>onLoad:</b> called just after an object is loaded<br>
* <br>
* <tt>onLoad()</tt> may be used to initialize transient properties of the
* object from its persistent state. It may <b>not</b> be used to load
* dependent objects since the <tt>Session</tt> interface may not be
* invoked from inside this method.<br>
* <br>
* A further intended usage of <tt>onLoad()</tt>, <tt>onSave()</tt> and
* <tt>onUpdate()</tt> is to store a reference to the <tt>Session</tt>
* for later use.<br>
* <br>
* If <tt>onSave()</tt>, <tt>onUpdate()</tt> or <tt>onDelete()</tt> return
* <tt>VETO</tt>, the operation is silently vetoed. If a
* <tt>CallbackException</tt> is thrown, the operation is vetoed and the
* exception is passed back to the application.<br>
* <br>
* Note that <tt>onSave()</tt> is called after an identifier is assigned
* to the object, except when identity column key generation is used.
*
* @see CallbackException
* @author Gavin King
*/
public interface Lifecycle {
/**
* Return value to veto the action (true)
*/
public static final boolean VETO = true;
/**
* Return value to accept the action (false)
*/
public static final boolean NO_VETO = false;
/**
* Called when an entity is saved.
* @param s the session
* @return true to veto save
* @throws CallbackException
*/
public boolean onSave(Session s) throws CallbackException;
/**
* Called when an entity is passed to <tt>Session.update()</tt>.
* This method is <em>not</em> called every time the object's
* state is persisted during a flush.
* @param s the session
* @return true to veto update
* @throws CallbackException
*/
public boolean onUpdate(Session s) throws CallbackException;
/**
* Called when an entity is deleted.
* @param s the session
* @return true to veto delete
* @throws CallbackException
*/
public boolean onDelete(Session s) throws CallbackException;
/**
* Called after an entity is loaded. <em>It is illegal to
* access the <tt>Session</tt> from inside this method.</em>
* However, the object may keep a reference to the session
* for later use.
*
* @param s the session
* @param id the identifier
*/
public void onLoad(Session s, Serializable id);
}