/*
 * $Header: /home/cvspublic/jakarta-slide/projector/src/java/org/apache/slide/projector/expression/OrExpression.java,v 1.4 2004/11/28 13:54:09 dflorey Exp $
 * $Revision: 1.4 $
 * $Date: 2004/11/28 13:54:09 $
 *
 * ====================================================================
 *
 * Copyright 1999-2002 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.slide.projector.expression;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.xmlio.out.XMLStringWriter;
import org.apache.commons.xmlio.out.XMLWriter;
import org.apache.slide.projector.engine.Job;

/**
 * The AndExpression class
 * 
 */
public class OrExpression implements EnclosingExpression {
    private List nestedExpressions = new ArrayList();

    public Expression activate(Job job) {
    	OrExpression activatedExpression = new OrExpression();
    	for ( Iterator i = nestedExpressions.iterator(); i.hasNext(); ) {
    		activatedExpression.addExpression(((Expression)i.next()).activate(job));
    	}
    	return activatedExpression;
    }
    
    public void addExpression(Expression expression) {
        nestedExpressions.add(expression);
    }

    public boolean evaluate() {
        boolean eval = false;
        for ( Iterator i = nestedExpressions.iterator(); i.hasNext(); ) {
            Expression expression = (Expression)i.next();
            if ( expression.evaluate()) {
                eval = true;
            }
        }
        return eval;
    }

    public void save(XMLStringWriter writer) {
        writer.writeStartTag(XMLWriter.createStartTag("or"));
        for ( Iterator i = nestedExpressions.iterator(); i.hasNext(); ) {
            Expression expression = (Expression)i.next();
            expression.save(writer);
        }
        writer.writeEndTag(XMLWriter.createEndTag("or"));
    }
}