1 /* 2 * Copyright 2002,2004 The Apache Software Foundation. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package org.apache.commons.jelly.tags.core; 17 18 import org.apache.commons.jelly.MissingAttributeException; 19 import org.apache.commons.jelly.TagSupport; 20 import org.apache.commons.jelly.XMLOutput; 21 import org.apache.commons.jelly.expression.Expression; 22 23 /** 24 * A tag which removes the variable of the given name from the current variable scope. 25 * 26 * @author <a HREF="mailto:jstrachan@apache.org">James Strachan</a> 27 * @version $Revision: 155420 $ 28 */ 29 public class RemoveTag extends TagSupport { 30 31 private Expression var; 32 33 public RemoveTag() { 34 } 35 36 // Tag interface 37 //------------------------------------------------------------------------- 38 public void doTag(XMLOutput output) throws MissingAttributeException { 39 if (var != null) { 40 context.removeVariable( var.evaluateAsString(context) ); 41 } 42 else { 43 throw new MissingAttributeException("var"); 44 } 45 } 46 47 // Properties 48 //------------------------------------------------------------------------- 49 50 /** 51 * Sets the name of the variable which will be removed by this tag.. 52 */ 53 public void setVar(Expression var) { 54 this.var = var; 55 } 56 } 57