/*
* Copyright 2002,2004 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.jelly.tags.core;
import org.apache.commons.jelly.JellyTagException;
import org.apache.commons.jelly.TagSupport;
import org.apache.commons.jelly.XMLOutput;
import org.apache.commons.jelly.expression.Expression;
/** A tag which conditionally evaluates its body based on some condition
*
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
* @version $Revision: 1.15 $
*/
public class WhenTag extends TagSupport {
/** The expression to evaluate. */
private Expression test;
public WhenTag() {
}
// Tag interface
//-------------------------------------------------------------------------
public void doTag(XMLOutput output) throws JellyTagException {
ChooseTag tag = (ChooseTag) findAncestorWithClass( ChooseTag.class );
if ( tag == null ) {
throw new JellyTagException( "This tag must be enclosed inside a <choose> tag" );
}
if ( ! tag.isBlockEvaluated() && test != null ) {
if ( test.evaluateAsBoolean( context ) ) {
tag.setBlockEvaluated(true);
invokeBody(output);
}
}
}
// Properties
//-------------------------------------------------------------------------
/** Sets the expression to evaluate. */
public void setTest(Expression test) {
this.test = test;
}
}