/**
* 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.el;
import java.util.HashMap;
import java.util.Map;
import javax.el.ELException;
import javax.el.ValueExpression;
import javax.el.VariableMapper;
/**
* Utility class for wrapping another VariableMapper with a new context,
* represented by a {@link java.util.Map Map}. Modifications occur to the Map
* instance, but resolve against the wrapped VariableMapper if the Map doesn't
* contain the ValueExpression requested.
*
* @author Jacob Hookom
* @version $Id: VariableMapperWrapper.java,v 1.6 2007/09/24 16:06:12 youngm Exp $
*/
public final class VariableMapperWrapper extends VariableMapper {
private final VariableMapper target;
private Map vars;
/**
*
*/
public VariableMapperWrapper(VariableMapper orig) {
super();
this.target = orig;
}
/**
* First tries to resolve agains the inner Map, then the wrapped
* ValueExpression.
*
* @see javax.el.VariableMapper#resolveVariable(java.lang.String)
*/
public ValueExpression resolveVariable(String variable) {
ValueExpression ve = null;
try {
if (this.vars != null) {
ve = (ValueExpression) this.vars.get(variable);
}
if (ve == null) {
return this.target.resolveVariable(variable);
}
return ve;
} catch (StackOverflowError e) {
throw new ELException("Could not Resolve Variable [Overflow]: " + variable, e);
}
}
/**
* Set the ValueExpression on the inner Map instance.
*
* @see javax.el.VariableMapper#setVariable(java.lang.String,
* javax.el.ValueExpression)
*/
public ValueExpression setVariable(String variable,
ValueExpression expression) {
if (this.vars == null) {
this.vars = new HashMap();
}
return (ValueExpression) this.vars.put(variable, expression);
}
}