/**
* License Agreement.
*
* Rich Faces - Natural Ajax for Java Server Faces (JSF)
*
* Copyright (C) 2007 Exadel, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.richfaces.view.facelets;
import java.io.IOException;
import java.io.Serializable;
import javax.el.ValueExpression;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.FacesEvent;
import javax.faces.event.FacesListener;
import javax.faces.view.AttachedObjectHandler;
import javax.faces.view.facelets.ComponentHandler;
import javax.faces.view.facelets.FaceletContext;
import javax.faces.view.facelets.TagAttribute;
import javax.faces.view.facelets.TagAttributeException;
import javax.faces.view.facelets.TagConfig;
import javax.faces.view.facelets.TagException;
import javax.faces.view.facelets.TagHandler;
/**
* @author akolonitsky
* @since Aug 31, 2010
*/
public abstract class EventListenerHandler extends TagHandler implements AttachedObjectHandler {
protected final TagAttribute binding;
protected final String listenerType;
public abstract static class LazyEventListener<L extends FacesListener> implements FacesListener, Serializable {
private static final long serialVersionUID = 1L;
protected final String type;
protected final ValueExpression binding;
protected LazyEventListener(String type, ValueExpression binding) {
this.type = type;
this.binding = binding;
}
public void processEvent(FacesEvent event) throws AbortProcessingException {
FacesContext faces = FacesContext.getCurrentInstance();
if (faces == null) {
return;
}
L instance = null;
if (this.binding != null) {
instance = (L) binding.getValue(faces.getELContext());
}
if (instance == null && this.type != null) {
try {
instance = (L) TagHandlerUtils.loadClass(this.type, Object.class).newInstance();
} catch (Exception e) {
throw new AbortProcessingException("Couldn't Lazily instantiate EventListener", e);
}
if (this.binding != null) {
binding.setValue(faces.getELContext(), instance);
}
}
if (instance != null) {
event.processListener(instance);
}
}
}
public EventListenerHandler(TagConfig config) {
super(config);
this.binding = this.getAttribute("binding");
TagAttribute type = this.getAttribute("type");
if (type != null) {
if (type.isLiteral()) {
try {
TagHandlerUtils.loadClass(type.getValue(), Object.class);
} catch (ClassNotFoundException e) {
throw new TagAttributeException(type, "Couldn't qualify EventListener", e);
}
} else {
throw new TagAttributeException(type, "Must be a literal class name of type EventListener");
}
this.listenerType = type.getValue();
} else {
this.listenerType = null;
}
}
public void apply(FaceletContext ctx, UIComponent parent) throws IOException {
// only process if it's been created
if (parent == null || !ComponentHandler.isNew(parent)) {
return;
}
if (isEventSource(parent)) {
applyAttachedObject(ctx.getFacesContext(), parent);
} else if (UIComponent.isCompositeComponent(parent)) {
// Allow the composite component to know about the target component.
TagHandlerUtils.getOrCreateRetargetableHandlersList(parent).add(this);
} else {
throw new TagException(this.tag, "Parent does not match event source requirements: " + parent);
}
}
public String getFor() {
TagAttribute attr = this.getAttribute("for");
return attr == null ? null : attr.getValue();
}
public abstract boolean isEventSource(UIComponent comp);
}