package org.apache.turbine.modules;
/* ====================================================================
* 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.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.turbine.Turbine;
import org.apache.turbine.TurbineConstants;
import org.apache.turbine.util.RunData;
import org.apache.turbine.util.parser.ParameterParser;
import org.apache.turbine.util.parser.ParserUtils;
/**
* <p>
*
* This is an alternative to the Action class that allows you to do
* event based actions. Essentially, you label all your submit buttons
* with the prefix of "eventSubmit_" and the suffix of "methodName".
* For example, "eventSubmit_doDelete". Then any class that subclasses
* this class will get its "doDelete(RunData data)" method executed.
* If for any reason, it was not able to execute the method, it will
* fall back to executing the doPeform() method which is required to
* be implemented.
*
* <p>
*
* Limitations:
*
* <p>
*
* Because ParameterParser makes all the key values lowercase, we have
* to do some work to format the string into a method name. For
* example, a button name eventSubmit_doDelete gets converted into
* eventsubmit_dodelete. Thus, we need to form some sort of naming
* convention so that dodelete can be turned into doDelete.
*
* <p>
*
* Thus, the convention is this:
*
* <ul>
* <li>The variable name MUST have the prefix "eventSubmit_".</li>
* <li>The variable name after the prefix MUST begin with the letters
* "do".</li>
* <li>The first letter after the "do" will be capitalized and the
* rest will be lowercase</li>
* </ul>
*
* If you follow these conventions, then you should be ok with your
* method naming in your Action class.
*
* @author <a href="mailto:jon@latchkey.com">Jon S. Stevens </a>
* @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
* @author <a href="quintonm@bellsouth.net">Quinton McCombs</a>
* @version $Id: ActionEvent.java,v 1.20 2003/09/02 07:48:30 henning Exp $
*/
public abstract class ActionEvent extends Action
{
/** Logging */
protected Log log = LogFactory.getLog(this.getClass());
/** Constant needed for Reflection */
private static final Class [] methodParams
= new Class [] { RunData.class };
/**
* You need to implement this in your classes that extend this class.
*
* @param data Turbine information.
* @exception Exception a generic exception.
*/
public abstract void doPerform(RunData data)
throws Exception;
/** The name of the button to look for. */
protected static final String BUTTON = "eventSubmit_";
/** The length of the button to look for. */
protected static final int BUTTON_LENGTH = BUTTON.length();
/** The prefix of the method name. */
protected static final String METHOD_NAME_PREFIX = "do";
/** The length of the method name. */
protected static final int METHOD_NAME_LENGTH = METHOD_NAME_PREFIX.length();
/** The length of the button to look for. */
protected static final int LENGTH = BUTTON.length();
/**
* If true, the eventSubmit_do<xxx> variable must contain
* a not null value to be executed.
*/
private boolean submitValueKey = false;
/**
* C'tor
*/
public ActionEvent()
{
super();
submitValueKey = Turbine.getConfiguration()
.getBoolean(TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_KEY,
TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_DEFAULT);
log.debug(submitValueKey
? "ActionEvent accepts only eventSubmit_do Keys with a value != 0"
: "ActionEvent accepts all eventSubmit_do Keys");
}
/**
* This overrides the default Action.perform() to execute the
* doEvent() method. If that fails, then it will execute the
* doPerform() method instead.
*
* @param data Turbine information.
* @exception Exception a generic exception.
*/
protected void perform(RunData data)
throws Exception
{
try
{
executeEvents(data);
}
catch (NoSuchMethodException e)
{
doPerform(data);
}
}
/**
* This method should be called to execute the event based system.
*
* @param data Turbine information.
* @exception Exception a generic exception.
*/
public void executeEvents(RunData data)
throws Exception
{
// Name of the button.
String theButton = null;
// Parameter parser.
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 };
if (log.isDebugEnabled())
{
log.debug("Invoking " + method);
}
method.invoke(this, methodArgs);
}
catch (InvocationTargetException ite)
{
Throwable t = ite.getTargetException();
log.error("Invokation of " + method , t);
}
finally
{
pp.remove(key);
}
}
/**
* This method does the conversion of the lowercase method name
* into the proper case.
*
* @param input The unconverted method name.
* @return A string with the method name in the proper case.
*/
protected final String formatString(String input)
{
String tmp = null;
if (StringUtils.isNotEmpty(input))
{
tmp = input.toLowerCase();
// Chop off suffixes (for image type)
input = (tmp.endsWith(".x") || tmp.endsWith(".y"))
? input.substring(0, input.length() - 2)
: input;
if (ParserUtils.getUrlFolding()
!= ParserUtils.URL_CASE_FOLDING_NONE)
{
tmp = tmp.substring(BUTTON_LENGTH + METHOD_NAME_LENGTH);
tmp = METHOD_NAME_PREFIX + StringUtils.capitalise(tmp);
}
else
{
tmp = input.substring(BUTTON_LENGTH);
}
}
return tmp;
}
/**
* Checks whether the selected key really is a valid event.
*
* @param key The selected key
* @param pp The parameter parser to look for the key value
*
* @return true if this key is really an ActionEvent Key
*/
protected boolean considerKey(String key, ParameterParser pp)
{
if (!submitValueKey)
{
log.debug("No Value required, accepting " + key);
return true;
}
else
{
// If the action.eventsubmit.needsvalue key is true,
// events with a "0" or empty value are ignored.
// This can be used if you have multiple eventSubmit_do<xxx>
// fields in your form which are selected by client side code,
// e.g. JavaScript.
//
// If this key is unset or missing, nothing changes for the
// current behaviour.
//
String keyValue = pp.getString(key);
log.debug("Key Value is " + keyValue);
if (StringUtils.isEmpty(keyValue))
{
log.debug("Key is empty, rejecting " + key);
return false;
}
try
{
if (Integer.parseInt(keyValue) != 0)
{
log.debug("Integer != 0, accepting " + key);
return true;
}
}
catch (NumberFormatException nfe)
{
// Not a number. So it might be a
// normal Key like "continue" or "exit". Accept
// it.
log.debug("Not a number, accepting " + key);
return true;
}
}
log.debug("Rejecting " + key);
return false;
}
}