| /* |
| * 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; |
| } |
| |
| } |