/*
 * Copyright 2001-2004 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.commons.betwixt.expression;


/** <p><code>ClassNameExpression</code> returns the current class name 
  * of the context bean
  *
  * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
  * @since 0.5
  */
public class ClassNameExpression implements Expression {

    /** Base constructor */
    public ClassNameExpression() {
    }
    
    /** 
     * Evaluate on the current context and return the class name  
     *
     * @param context the context against which this expression will be evaluated
     * @return the name of the class of the current contex bean
     */
    public Object evaluate(Context context) {
        Object bean = context.getBean();
        if ( bean != null ) {
            return bean.getClass().getName();
        }
        return null;
    }

    /** 
     * Do nothing.
     * @see org.apache.commons.betwixt.expression.Expression
     */
    public void update(Context context, String newValue) {
        // do nothing
    }
    
    /** 
     * Returns something useful for logging.
     * @return something useful for logging
     */
    public String toString() {
        return "ClassNameExpression";
    }
}