org.apache.taglibs.standard.lang.jstl.VariableResolver Maven / Gradle / Ivy
/*
* Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
* Copyright 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;
/**
*
* This class is used to customize the way the evaluator resolves
* variable references. For example, instances of this class can
* implement their own variable lookup mechanisms, or introduce the
* notion of "implicit variables" which override any other variables.
* An instance of this class should be passed to the evaluator's
* constructor.
*
*
Whenever the evaluator is invoked, it is passed a "context"
* Object from the application. For example, in a JSP environment,
* the "context" is a PageContext. That context object is eventually
* passed to this class, so that this class has a context in which to
* resolve variables.
*
* @author Nathan Abramson - Art Technology Group
* @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: kchung $
**/
public interface 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;
//-------------------------------------
}