/*
* 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 javax.servlet.jsp.tagext.TagSupport;
import javax.servlet.jsp.JspException;
import javax.faces.webapp.UIComponentClassicTagBase;
import javax.faces.webapp.UIComponentELTag;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.el.ValueExpression;
import javax.el.ELContext;
import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspAttribute;
import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspTag;
/**
* This tag associates an attribute with the nearest parent UIComponent.
* <p>
* When the value is not an EL expression, this tag has the same effect as calling component.getAttributes.put(name,
* value). When the attribute name specified matches a standard property of the component, that property is set. However
* it is also valid to assign attributes to components using any arbitrary name; the component itself won't make any use
* of these but other objects such as custom renderers, validators or action listeners can later retrieve the attribute
* from the component by name.
* </p>
* <p>
* When the value is an EL expression, this tag has the same effect as calling component.setValueBinding. A call to
* method component.getAttributes().get(name) will then cause that expression to be evaluated and the result of the
* expression is returned, not the original EL expression string.
* </p>
* <p>
* See the javadoc for UIComponent.getAttributes for more details.
* </p>
* <p>
* Unless otherwise specified, all attributes accept static values or EL expressions.
* </p>
*
* @author Manfred Geiler (latest modification by $Author: lu4242 $)
* @author Bruno Aranda (JSR-252)
* @version $Revision: 819754 $ $Date: 2009-09-28 17:27:45 -0500 (Mon, 28 Sep 2009) $
*/
@JSFJspTag(name = "f:attribute", bodyContent = "empty")
public class AttributeTag extends TagSupport
{
private static final long serialVersionUID = 31476300171678632L;
private ValueExpression _nameExpression;
private ValueExpression _valueExpression;
/**
* The name of the attribute.
*
* @param nameExpression
*/
@JSFJspAttribute(className="javax.el.ValueExpression",
deferredValueType="java.lang.String")
public void setName(ValueExpression nameExpression)
{
_nameExpression = nameExpression;
}
/**
* The attribute's value.
*
* @param valueExpression
*/
@JSFJspAttribute(className="javax.el.ValueExpression",
deferredValueType="java.lang.Object")
public void setValue(ValueExpression valueExpression)
{
_valueExpression = valueExpression;
}
@Override
public int doStartTag() throws JspException
{
UIComponentClassicTagBase componentTag = UIComponentELTag.getParentUIComponentClassicTagBase(pageContext);
if (componentTag == null)
{
throw new JspException("no parent UIComponentTag found");
}
UIComponent component = componentTag.getComponentInstance();
if (component == null)
{
throw new JspException("parent UIComponentTag has no UIComponent");
}
FacesContext facesContext = FacesContext.getCurrentInstance();
ELContext elContext = facesContext.getELContext();
String name = null;
Object value = null;
boolean isLiteral = false;
if (_nameExpression != null)
{
name = (String)_nameExpression.getValue(elContext);
}
if (_valueExpression != null)
{
isLiteral = _valueExpression.isLiteralText();
value = _valueExpression.getValue(elContext);
}
if (name != null)
{
if (component.getAttributes().get(name) == null)
{
if (isLiteral)
{
component.getAttributes().put(name, value);
}
else
{
component.setValueExpression(name, _valueExpression);
}
}
}
return SKIP_BODY;
}
@Override
public void release()
{
super.release();
_nameExpression = null;
_valueExpression = null;
}
}