/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.myfaces.taglib.core;
import java.io.Serializable;
import java.util.logging.Logger;
import javax.el.ValueExpression;
import javax.faces.FacesException;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;
import javax.faces.webapp.UIComponentELTag;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.Tag;
import javax.servlet.jsp.tagext.TagSupport;
import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspAttribute;
import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspTag;
import org.apache.myfaces.shared.util.ClassUtils;
/**
* Register a PhaseListener instance
*
* @author martin.haimberger
* @version $Revision: 462929 $ $Date: 2006-10-11 21:26:36 +0100 (mi�, 11 oct 2006) $
*/
@JSFJspTag(name = "f:phaseListener", bodyContent = "empty")
public class PhaseListenerTag extends TagSupport
{
private static final Logger log = Logger.getLogger(PhaseListenerTag.class.getName());
/**
* The fully qualified class name of the PhaseListener which should be created.
*/
private ValueExpression type = null;
/**
* A value binding expression used to create a PhaseListener instance.
*/
private ValueExpression binding = null;
/**
* Class name of the PhaseListener to be created and registered.
*/
@JSFJspAttribute(className="javax.el.ValueExpression",
deferredValueType="java.lang.String")
public void setType(ValueExpression type)
{
this.type = type;
}
/**
* Value binding expression that evaluates to a PhaseListener.
*/
@JSFJspAttribute(className="javax.el.ValueExpression",
deferredValueType="javax.faces.event.PhaseListener")
public void setBinding(ValueExpression binding)
{
this.binding = binding;
}
@Override
public int doStartTag() throws JspException
{
// JSF-Spec 1.2 9.4.9
// Locate the one and only UIViewRoot custom action instance by walking up the tag tree
// until you find a UIComponentELTag instance that has no parent. If the
// getCreated() method of this instance returns true, check the binding attribute.
Tag parent = this;
UIComponentELTag parentTag = null;
while ((parent = parent.getParent()) != null)
{
if (parent instanceof UIComponentELTag)
{
parentTag = (UIComponentELTag)parent;
}
}
if (parentTag == null)
{
throw new JspException("Not nested in a UIViewRoot Error for tag with handler class: "
+ this.getClass().getName());
}
if (!parentTag.getCreated())
{
return SKIP_BODY;
}
UIViewRoot root = (UIViewRoot)parentTag.getComponentInstance();
// JSF-Spec 1.2 9.4.9
// If binding is set, call binding.getValue() to obtain a reference to the
// PhaseListener instance. If there is no exception thrown, and binding.getValue()
// returned a non-null object that implements javax.faces.event.PhaseListener, register
// it by calling addPhaseListener(). If there was an exception thrown, rethrow the
// exception as a JspException.
// If the listener instance could not be created, check the type attribute. If the type
// attribute is set, instantiate an instance of the specified class, and register it by calling
// addPhaseListener(). If the binding attribute was also set, store the listener instance
// by calling binding.setValue(). If there was an exception thrown, rethrow the
// exception as a JspException.
PhaseListener listener = null;
try
{
listener = new BindingPhaseListener(binding, type);
}
catch (Exception ex)
{
throw new JspException(ex.getMessage(), ex);
}
root.addPhaseListener(listener);
return SKIP_BODY;
}
private static class BindingPhaseListener implements PhaseListener, Serializable
{
private transient PhaseListener phaseListenerCache = null;
private ValueExpression type;
private ValueExpression binding;
//private final Log log = LogFactory.getLog(PhaseListenerTag.class);
BindingPhaseListener(ValueExpression binding, ValueExpression type)
{
this.binding = binding;
this.type = type;
}
public void afterPhase(PhaseEvent event)
{
PhaseListener listener = getPhaseListener();
if (listener != null)
{
listener.afterPhase(event);
}
}
public void beforePhase(PhaseEvent event)
{
PhaseListener listener = getPhaseListener();
if (listener != null)
{
listener.beforePhase(event);
}
}
public PhaseId getPhaseId()
{
PhaseListener listener = getPhaseListener();
if (listener != null)
{
return listener.getPhaseId();
}
return null;
}
private PhaseListener getPhaseListener()
{
if (phaseListenerCache != null)
{
return phaseListenerCache;
}
else
{
// create PhaseListenerInstance
phaseListenerCache = getPhaseListnerInstance(binding, type);
}
if (phaseListenerCache == null)
{
log.warning("PhaseListener will not be installed. Both binding and type are null.");
}
return phaseListenerCache;
}
private PhaseListener getPhaseListnerInstance(ValueExpression binding, ValueExpression type)
{
FacesContext currentFacesContext = FacesContext.getCurrentInstance();
Object phasesInstance = null;
if (binding != null)
{
phasesInstance = binding.getValue(currentFacesContext.getELContext());
}
else if (type != null)
{
try
{
phasesInstance = ClassUtils.newInstance((String)type.getValue(currentFacesContext.getELContext()));
}
catch (FacesException ex)
{
throw new AbortProcessingException(ex.getMessage(), ex);
}
}
return (PhaseListener)phasesInstance;
}
}
}