/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed 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.taglibs.standard.lang.jstl;
import javax.servlet.jsp.PageContext;
/**
*
* <p>This is the JSTL-specific implementation of VariableResolver.
* It looks up variable references in the PageContext, and also
* recognizes references to implicit objects.
*
* @author Nathan Abramson - Art Technology Group
* @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: pierred $
**/
public class JSTLVariableResolver
implements VariableResolver
{
//-------------------------------------
/**
*
* Resolves the specified variable within the given context.
* Returns null if the variable is not found.
**/
public Object resolveVariable (String pName,
Object pContext)
throws ELException
{
PageContext ctx = (PageContext) pContext;
// Check for implicit objects
if ("pageContext".equals (pName)) {
return ctx;
}
else if ("pageScope".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getPageScopeMap ();
}
else if ("requestScope".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getRequestScopeMap ();
}
else if ("sessionScope".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getSessionScopeMap ();
}
else if ("applicationScope".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getApplicationScopeMap ();
}
else if ("param".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getParamMap ();
}
else if ("paramValues".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getParamsMap ();
}
else if ("header".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getHeaderMap ();
}
else if ("headerValues".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getHeadersMap ();
}
else if ("initParam".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getInitParamMap ();
}
else if ("cookie".equals (pName)) {
return ImplicitObjects.
getImplicitObjects (ctx).
getCookieMap ();
}
// Otherwise, just look it up in the page context
else {
return ctx.findAttribute (pName);
}
}
//-------------------------------------
}