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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
    17  package org.apache.commons.jelly;
    18
    19  import java.util.HashMap;
    20
    21  import java.util.Map;
    22
    23  /***
    24   * <p><code>MapTag</code> is a DynaTag implementation which uses a Map
    25   * to store its attribute values in. Derived tags can then process this
    26   * Map, change values, add or remove attributes or perform some other form
    27   * of processsing pretty easily.
    28   * </p>
    29   *
    30   * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
    31   * @version $Revision: 155420 $
    32   */
    33
    34  public abstract class MapTagSupport extends DynaTagSupport {
    35
    36      private Map map;
    37
    38      /*** Sets an attribute value of this tag before the tag is invoked
    39       */
    40      public void setAttribute(String name, Object value) {
    41          getAttributes().put(name, value);
    42      }
    43
    44      /***
    45       * Helper method which allows derived tags to access the attributes
    46       * associated with this tag
    47       */
    48      protected Map getAttributes() {
    49          if (map == null) {
    50              map = createAttributes();
    51          }
    52          return map;
    53      }
    54      /***
    55       * A Factory Method which allows derived tags to overload the Map
    56       * implementation used by this tag
    57       */
    58
    59      protected Map createAttributes() {
    60          return new HashMap();
    61      }
    62
    63  }