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    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  }