/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.sun.faces.el;
import javax.el.ELResolver;
import javax.el.ValueExpression;
import javax.faces.context.FacesContext;
import javax.faces.el.EvaluationException;
import javax.faces.el.VariableResolver;
import com.sun.faces.util.RequestStateManager;
import com.sun.faces.el.FacesCompositeELResolver.ELResolverChainType;
/**
* <p> This special VariableResolver serves as the "original"
* VariableResolver that is passed to the one-arg ctor for the
* <b>first</b> custom VariableResolver that is encountered during
* application configuration. Subsequent VariableResolver instances get
* passed the previous VariableResolver instance, per section 10.4.5 of
* the spec. </p>
*
* <p>The "specialness" of this VariableResolver is found in its {@link
* #resolveVariable} method, which delegates to the head of the
* "correct" ELResolver chain based on the context in which this
* expression is being evaluated. If the expression being evaluated
* originated in a JSP page, the <code>Application</code>'s
* <code>ExpressionFactory</code> is used to create a
* <code>ValueExpression</code>, which is then evaluated to resolve the
* variable. This will cause the ELResolver chain described in section
* 5.6.1 of the spec to be used. If the expression being evaluated
* originated in a programmatic API call, the <code>Application</code>'s
* <code>ELResolver</code> is used to resolve the variable. This will
* cause the ELResolver chain described in section 5.6.2 of the spec to
* be used.</p>
*/
@SuppressWarnings("deprecation")
public class ChainAwareVariableResolver extends VariableResolver {
public ChainAwareVariableResolver() {
}
//
// Relationship Instance Variables
//
/**
* See the class javadocs.
*/
public Object resolveVariable(FacesContext context, String name)
throws EvaluationException {
Object result = null;
ELResolverChainType type = ELResolverChainType.Faces;
Object valueObject = RequestStateManager.get(context,
RequestStateManager.EL_RESOLVER_CHAIN_TYPE_NAME);
if (null != valueObject &&
valueObject instanceof ELResolverChainType) {
type = (ELResolverChainType) valueObject;
}
if (ELResolverChainType.JSP == type) {
ValueExpression ve = context.getApplication().getExpressionFactory()
.createValueExpression(context.getELContext(),
"#{" + name + "}", Object.class);
result = ve.getValue(context.getELContext());
} else if (ELResolverChainType.Faces == type) {
ELResolver elr = context.getApplication().getELResolver();
result = elr.getValue(context.getELContext(), null, name);
}
return result;
}
}