code: /**
   * boilerpipe
   *
   * Copyright (c) 2009, 2014 Christian Kohlschütter
   *
   * The author licenses this file to You 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 com.kohlschutter.boilerpipe.sax;
  
  import java.util.HashMap;
  
  /**
   * Base class for definition a set of {@link TagAction}s that are to be used for the HTML parsing
   * process.
   * 
   * @see DefaultTagActionMap
   */
  public abstract class TagActionMap extends HashMap<String, TagAction> {
    private static final long serialVersionUID = 1L;
  
    /**
     * Sets a particular {@link TagAction} for a given tag. Any existing TagAction for that tag will
     * be removed and overwritten.
     * 
     * @param tag The tag (will be stored internally 1. as it is, 2. lower-case, 3. upper-case)
     * @param action The {@link TagAction}
     */
    protected void setTagAction(final String tag, final TagAction action) {
      put(tag.toUpperCase(), action);
      put(tag.toLowerCase(), action);
      put(tag, action);
    }
  
    /**
     * Adds a particular {@link TagAction} for a given tag. If a TagAction already exists for that
     * tag, a chained action, consisting of the previous and the new {@link TagAction} is created.
     * 
     * @param tag The tag (will be stored internally 1. as it is, 2. lower-case, 3. upper-case)
     * @param action The {@link TagAction}
     */
    protected void addTagAction(final String tag, final TagAction action) {
      TagAction previousAction = get(tag);
      if (previousAction == null) {
        setTagAction(tag, action);
      } else {
        setTagAction(tag, new CommonTagActions.Chained(previousAction, action));
      }
    }
  }
  