| /* |
| * 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.xml; |
| |
| import org.apache.commons.jelly.JellyTagException; |
| import org.apache.commons.jelly.MissingAttributeException; |
| import org.apache.commons.jelly.XMLOutput; |
| import org.apache.commons.jelly.xpath.XPathTagSupport; |
| import org.jaxen.JaxenException; |
| import org.jaxen.XPath; |
| |
| /** |
| * Evaluates the XPath expression to be a boolean and only evaluates the body |
| * if the expression is true. |
| * @author <a href="mailto:jstrachan@apache.org">James Strachan</a> |
| * @version $Revision: 1.5 $ |
| */ |
| public class IfTag extends XPathTagSupport { |
| |
| /** The XPath expression to evaluate. */ |
| private XPath select; |
| |
| public IfTag() { |
| } |
| |
| // Tag interface |
| //------------------------------------------------------------------------- |
| public void doTag(XMLOutput output) throws MissingAttributeException, JellyTagException { |
| if (select == null) { |
| throw new MissingAttributeException( "select" ); |
| } |
| |
| Object xpathContext = getXPathContext(); |
| |
| try { |
| if ( select.booleanValueOf(xpathContext) ) { |
| invokeBody(output); |
| } |
| } catch (JaxenException e) { |
| throw new JellyTagException(e); |
| } |
| } |
| |
| // Properties |
| //------------------------------------------------------------------------- |
| |
| /** Sets the XPath expression to evaluate. */ |
| public void setSelect(XPath select) { |
| this.select = select; |
| } |
| |
| // Implementation methods |
| //------------------------------------------------------------------------- |
| protected Object getXPathContext() { |
| ForEachTag tag = (ForEachTag) findAncestorWithClass( ForEachTag.class ); |
| if ( tag != null ) { |
| return tag.getXPathContext(); |
| } |
| return null; |
| } |
| |
| } |