/*
* $Id: PhaseListenerTag.java,v 1.13 2006/12/18 18:58:15 rlubke Exp $
*/
/*
* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the License). You may not use this file except in
* compliance with the License.
*
* You can obtain a copy of the License at
* https://javaserverfaces.dev.java.net/CDDL.html or
* legal/CDDLv1.0.txt.
* See the License for the specific language governing
* permission and limitations under the License.
*
* When distributing Covered Code, include this CDDL
* Header Notice in each file and include the License file
* at legal/CDDLv1.0.txt.
* If applicable, add the following below the CDDL Header,
* with the fields enclosed by brackets [] replaced by
* your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* [Name of File] [ver.__] [Date]
*
* Copyright 2005 Sun Microsystems Inc. All Rights Reserved
*/
package com.sun.faces.taglib.jsf_core;
import com.sun.faces.util.MessageUtils;
import com.sun.faces.util.Util;
import javax.el.ValueExpression;
import javax.faces.component.UIComponent;
import javax.faces.component.UIViewRoot;
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 java.io.Serializable;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* <p>Tag implementation that creates a {@link PhaseListener} instance
* and registers it on the {@link UIViewRoot} associated with our most
* immediate surrounding instance of a tag whose component
* is an instance of {@link UIViewRoot}. This tag creates no output to the
* page currently being created.</p>
* <p/>
*/
public class PhaseListenerTag extends TagSupport {
private static final Logger logger =
Util.getLogger(Util.FACES_LOGGER + Util.TAGLIB_LOGGER);
// ------------------------------------------------------------- Attributes
/**
* <p>The fully qualified class name of the {@link PhaseListener}
* instance to be created.</p>
*/
private ValueExpression type = null;
/**
* <p>The value binding expression used to create a listener
* instance and it is also used to wire up this listener to an
* {@link PhaseListener} property of a JavaBean class.</p>
*/
private ValueExpression binding = null;
/**
* <p>Set the fully qualified class name of the
* {@link PhaseListener} instance to be created.
*
* @param type The new class name
*/
public void setType(ValueExpression type) {
this.type = type;
}
/*
* <p>Set the value binding expression for this listener.</p>
*
* @param binding The new value binding expression
*/
public void setBinding(ValueExpression binding) {
this.binding = binding;
}
// --------------------------------------------------------- Public Methods
/**
* <p>Create a new instance of the specified {@link PhaseListener}
* class, and register it with the {@link UIComponent} instance associated
* with our most immediately surrounding {@link UIComponentELTag} instance, if
* the {@link UIComponent} instance was created by this execution of the
* containing JSP page.</p>
*
* @throws JspException if a JSP error occurs
*/
public int doStartTag() throws JspException {
// find the viewTag
Tag parent = this;
UIComponentELTag tag = null;
while (null != (parent = parent.getParent())) {
if (parent instanceof UIComponentELTag) {
tag = (UIComponentELTag) parent;
}
}
if (tag == null) {
Object params[] = {this.getClass().getName()};
throw new JspException(
MessageUtils.getExceptionMessageString(
MessageUtils.NOT_NESTED_IN_FACES_TAG_ERROR_MESSAGE_ID, params));
}
// Nothing to do unless this tag created a component
if (!tag.getCreated()) {
return (SKIP_BODY);
}
UIViewRoot viewRoot = (UIViewRoot) tag.getComponentInstance();
if (viewRoot == null) {
throw new JspException(
MessageUtils.getExceptionMessageString(MessageUtils.NULL_COMPONENT_ERROR_MESSAGE_ID));
}
// If binding is null, type is set and is a literal value,
// then don't bother wrapping. Just instantiate and
// set.
PhaseListener listener;
if (binding == null && type != null && type.isLiteralText()) {
try {
listener = (PhaseListener)
Util.getListenerInstance(type, null);
} catch (Exception e) {
throw new JspException(e.getMessage(), e.getCause());
}
} else {
listener = new BindingPhaseListener(type, binding);
}
viewRoot.addPhaseListener(listener);
return (SKIP_BODY);
}
/**
* <p>Release references to any acquired resources.
*/
public void release() {
this.type = null;
}
// ----------------------------------------------------------- Inner Classes
private static class BindingPhaseListener
implements PhaseListener, Serializable {
private transient PhaseListener instance;
private ValueExpression type;
private ValueExpression binding;
// -------------------------------------------------------- Constructors
public BindingPhaseListener(ValueExpression type,
ValueExpression binding) {
this.type = type;
this.binding = binding;
}
// ------------------------------------------ Methods from PhaseListener
/**
* <p>Handle a notification that the processing for a particular
* phase has just been completed.</p>
*/
public void afterPhase(PhaseEvent event) {
PhaseListener listener = getPhaseListener();
if (listener != null) {
listener.afterPhase(event);
}
}
/**
* <p>Handle a notification that the processing for a particular
* phase of the request processing lifecycle is about to begin.</p>
*/
public void beforePhase(PhaseEvent event) {
PhaseListener listener = getPhaseListener();
if (listener != null) {
listener.beforePhase(event);
}
}
/**
* <p>Return the identifier of the request processing phase during
* which this listener is interested in processing {@link javax.faces.event.PhaseEvent}
* events. Legal values are the singleton instances defined by the
* {@link javax.faces.event.PhaseId} class, including <code>PhaseId.ANY_PHASE</code>
* to indicate an interest in being notified for all standard phases.</p>
*/
public PhaseId getPhaseId() {
PhaseListener listener = getPhaseListener();
if (listener != null) {
return listener.getPhaseId();
}
return null;
}
/**
* <p>Invoked when the value change described by the specified
* {@link javax.faces.event.ValueChangeEvent} occurs.</p>
*
* @return a <code>PhaseListener</code> instance
* @throws javax.faces.event.AbortProcessingException
* Signal the JavaServer Faces
* implementation that no further processing on the current event
* should be performed
*/
public PhaseListener getPhaseListener() throws AbortProcessingException {
if (instance == null) {
instance = (PhaseListener)
Util.getListenerInstance(type, binding);
}
if (instance != null) {
return instance;
} else {
if (logger.isLoggable(Level.WARNING)) {
// PENDING i18n
logger.warning("PhaseListener will not be processed - " +
"both 'binding' and 'type' are null");
}
return null;
}
}
}
}