package org.apache.turbine.util.velocity;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache Turbine" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache Turbine", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Iterator;
import org.apache.turbine.modules.ActionEvent;
import org.apache.turbine.services.velocity.TurbineVelocity;
import org.apache.turbine.util.RunData;
import org.apache.turbine.util.parser.ParameterParser;
import org.apache.velocity.context.Context;
/**
* If you are using VelocitySite stuff, then your Action's should
* extend this class instead of extending the ActionEvent class. The
* difference between this class and the ActionEvent class is that
* this class will first attempt to execute one of your doMethod's
* with a constructor like this:
*
* <p><code>doEvent(RunData data, Context context)</code></p>
*
* <p>It gets the context from the TemplateInfo.getTemplateContext()
* method. If it can't find a method like that, then it will try to
* execute the method without the Context in it.</p>
*
* @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
* @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
* @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
* @version $Id: VelocityActionEvent.java,v 1.18 2003/08/20 10:58:28 henning Exp $
*/
public abstract class VelocityActionEvent extends ActionEvent
{
/** Constant needed for Reflection */
private static final Class [] methodParams
= new Class [] { RunData.class, Context.class };
/**
* You need to implement this in your classes that extend this
* class.
*
* @param data A Turbine RunData object.
* @exception Exception a generic exception.
*/
public abstract void doPerform(RunData data)
throws Exception;
/**
* This overrides the default Action.perform() to execute the
* doEvent() method. If that fails, then it will execute the
* doPerform() method instead.
*
* @param data A Turbine RunData object.
* @exception Exception a generic exception.
*/
protected void perform(RunData data)
throws Exception
{
try
{
executeEvents(data, TurbineVelocity.getContext(data));
}
catch (NoSuchMethodException e)
{
doPerform(data);
}
}
/**
* This method should be called to execute the event based system.
*
* @param data A Turbine RunData object.
* @param context Velocity context information.
* @exception Exception a generic exception.
*/
public void executeEvents(RunData data, Context context)
throws Exception
{
// Name of the button.
String theButton = null;
// ParameterParser.
ParameterParser pp = data.getParameters();
String button = pp.convert(BUTTON);
String key = null;
// Loop through and find the button.
for (Iterator it = pp.keySet().iterator(); it.hasNext();)
{
key = (String) it.next();
if (key.startsWith(button))
{
if (considerKey(key, pp))
{
theButton = formatString(key);
break;
}
}
}
if (theButton == null)
{
throw new NoSuchMethodException(
"ActionEvent: The button was null");
}
Method method = null;
try
{
method = getClass().getMethod(theButton, methodParams);
Object[] methodArgs = new Object[] { data, context };
if (log.isDebugEnabled())
{
log.debug("Invoking " + method);
}
method.invoke(this, methodArgs);
}
catch (NoSuchMethodException nsme)
{
// Attempt to execute things the old way..
if (log.isDebugEnabled())
{
log.debug("Couldn't locate the Event ( " + theButton
+ "), running executeEvents() in "
+ super.getClass().getName());
}
super.executeEvents(data);
}
catch (InvocationTargetException ite)
{
Throwable t = ite.getTargetException();
log.error("Invokation of " + method , t);
}
finally
{
pp.remove(key);
}
}
}