package org.apache.myfaces.tobago.taglib.component;
/*
* 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.
*/
import org.apache.myfaces.tobago.apt.annotation.BodyContent;
import org.apache.myfaces.tobago.apt.annotation.Tag;
import org.apache.myfaces.tobago.apt.annotation.TagAttribute;
import org.apache.myfaces.tobago.component.ComponentUtil;
import org.apache.myfaces.tobago.event.TabChangeListener;
import org.apache.myfaces.tobago.event.TabChangeSource;
import org.apache.myfaces.tobago.event.TabChangeListenerValueBindingDelegate;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import javax.faces.webapp.UIComponentTag;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;
/**
* Register an TabChangedListener instance on the UIComponent
* associated with the closest parent UIComponent custom action.
*/
@Tag(name = "tabChangeListener", bodyContent = BodyContent.EMPTY)
public class TabChangeListenerTag extends TagSupport {
private static final long serialVersionUID = -419199086962377873L;
private static final Log LOG = LogFactory.getLog(TabChangeListenerTag.class);
/**
* <p>The fully qualified class name of the {@link TabChangeListener}
* instance to be created.</p>
*/
private String type;
private String binding;
/**
* Fully qualified Java class name of a TabChangeListener to be
* created and registered.
*/
@TagAttribute(required = true)
public void setType(String type) {
this.type = type;
}
/**
* The value binding expression to a TabChangeListener.
*/
@TagAttribute
public void setBinding(String binding) {
this.binding = binding;
}
/**
* <p>Create a new instance of the specified {@link TabChangeListener}
* class, and register it with the {@link javax.faces.component.UIComponent} instance associated
* with our most immediately surrounding {@link javax.faces.webapp.UIComponentTag} instance, if
* the {@link javax.faces.component.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 {
// Locate our parent UIComponentTag
UIComponentTag tag =
UIComponentTag.getParentUIComponentTag(pageContext);
if (tag == null) {
// TODO Message resource i18n
throw new JspException("Not nested in faces tag");
}
if (!tag.getCreated()) {
return (SKIP_BODY);
}
UIComponent component = tag.getComponentInstance();
if (component == null) {
// TODO Message resource i18n
throw new JspException("Component Instance is null");
}
if (!(component instanceof TabChangeSource)) {
// TODO Message resource i18n
throw new JspException("Component " + component.getClass().getName() + " is not instanceof TabChangeSource");
}
TabChangeSource changeSource = (TabChangeSource) component;
TabChangeListener handler = null;
ValueBinding valueBinding = null;
if (binding != null && UIComponentTag.isValueReference(binding)) {
valueBinding = ComponentUtil.createValueBinding(binding);
if (valueBinding != null) {
Object obj = valueBinding.getValue(FacesContext.getCurrentInstance());
if (obj != null && obj instanceof TabChangeListener) {
handler = (TabChangeListener) obj;
}
}
}
if (handler == null && type != null) {
handler = createTabChangeListener(type);
if (handler != null && valueBinding != null) {
valueBinding.setValue(FacesContext.getCurrentInstance(), handler);
}
}
if (handler != null) {
if (valueBinding != null) {
changeSource.addTabChangeListener(new TabChangeListenerValueBindingDelegate(type, valueBinding));
} else {
changeSource.addTabChangeListener(handler);
}
}
// TODO else LOG.warn?
return (SKIP_BODY);
}
/**
* <p>Release references to any acquired resources.
*/
public void release() {
this.type = null;
this.binding = null;
}
/**
* <p>Create and return a new {@link TabChangeListener} to be registered
* on our surrounding {@link javax.faces.component.UIComponent}.</p>
*
* @throws javax.servlet.jsp.JspException if a new instance cannot be created
*/
protected TabChangeListener createTabChangeListener(String className) throws JspException {
try {
Class clazz = getClass().getClassLoader().loadClass(className);
return ((TabChangeListener) clazz.newInstance());
} catch (Exception e) {
throw new JspException(e);
}
}
}