/**
* Licensed under the Common Development and Distribution License,
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.sun.com/cddl/
*
* 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 com.sun.facelets.tag.jsf.core;
import java.io.IOException;
import java.io.Serializable;
import javax.el.ELException;
import javax.el.ValueExpression;
import javax.faces.FacesException;
import javax.faces.component.ActionSource;
import javax.faces.component.EditableValueHolder;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.ActionEvent;
import javax.faces.event.ActionListener;
import javax.faces.event.ValueChangeListener;
import com.sun.facelets.FaceletContext;
import com.sun.facelets.FaceletException;
import com.sun.facelets.tag.TagAttribute;
import com.sun.facelets.tag.TagAttributeException;
import com.sun.facelets.tag.TagConfig;
import com.sun.facelets.tag.TagException;
import com.sun.facelets.tag.TagHandler;
import com.sun.facelets.tag.jsf.ComponentSupport;
import com.sun.facelets.util.ReflectionUtil;
/**
* Register an ActionListener instance on the UIComponent associated with the
* closest parent UIComponent custom action. <p/> See <a target="_new"
* href="http://java.sun.com/j2ee/javaserverfaces/1.1_01/docs/tlddocs/f/actionListener.html">tag
* documentation</a>.
*
* @see javax.faces.event.ActionListener
* @see javax.faces.component.ActionSource
* @author Jacob Hookom
* @version $Id: ActionListenerHandler.java,v 1.5 2006/10/20 01:14:45 jhook Exp $
*/
public final class ActionListenerHandler extends TagHandler {
private final static class LazyActionListener implements ActionListener, Serializable {
private transient ActionListener instance;
private final String type;
private final ValueExpression binding;
public LazyActionListener(String type, ValueExpression binding) {
this.type = type;
this.binding = binding;
}
public void processAction(ActionEvent event) throws AbortProcessingException {
if (this.instance == null) {
FacesContext faces = FacesContext.getCurrentInstance();
if (faces == null)
return;
if (this.binding != null) {
this.instance = (ActionListener) binding
.getValue(faces.getELContext());
}
if (this.instance == null && this.type != null) {
try {
this.instance = (ActionListener) ReflectionUtil
.forName(this.type).newInstance();
} catch (Exception e) {
throw new AbortProcessingException(
"Couldn't Lazily instantiate ValueChangeListener",
e);
}
if (this.binding != null) {
binding.setValue(faces.getELContext(), this.instance);
}
}
}
if (this.instance != null) {
this.instance.processAction(event);
}
}
}
private final TagAttribute type;
private final TagAttribute binding;
private final String listenerType;
/**
* @param config
*/
public ActionListenerHandler(TagConfig config) {
super(config);
this.binding = this.getAttribute("binding");
this.type = this.getAttribute("type");
if (this.type != null) {
if (!this.type.isLiteral()) {
throw new TagAttributeException(this.type,
"Must be a literal class name of type ActionListener");
} else {
// test it out
try {
Class c = ReflectionUtil.forName(this.type.getValue());
} catch (ClassNotFoundException e) {
throw new TagAttributeException(this.type,
"Couldn't qualify ActionListener", e);
}
}
this.listenerType = this.type.getValue();
} else {
this.listenerType = null;
}
}
/*
* (non-Javadoc)
*
* @see com.sun.facelets.FaceletHandler#apply(com.sun.facelets.FaceletContext,
* javax.faces.component.UIComponent)
*/
public void apply(FaceletContext ctx, UIComponent parent)
throws IOException, FacesException, FaceletException, ELException {
if (parent instanceof ActionSource) {
if (ComponentSupport.isNew(parent)) {
ActionSource as = (ActionSource) parent;
ValueExpression b = null;
if (this.binding != null) {
b = this.binding.getValueExpression(ctx, ActionListener.class);
}
ActionListener listener = new LazyActionListener(this.listenerType, b);
as.addActionListener(listener);
}
} else {
throw new TagException(this.tag,
"Parent is not of type ActionSource, type is: " + parent);
}
}
}