content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software GmbH & Co. KG, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.workplace.tools.content;
  
  import org.opencms.util.CmsHtmlParser;
  import org.opencms.util.CmsHtmlTagRemoveFactory;
  import org.opencms.util.CmsStringUtil;
  
  import java.util.Iterator;
  
  import org.htmlparser.NodeFactory;
  import org.htmlparser.Parser;
  import org.htmlparser.Tag;
  import org.htmlparser.lexer.Lexer;
  import org.htmlparser.lexer.Page;
  import org.htmlparser.util.ParserException;
  
  /**
   *
   * Html parser / visitor combination that visits a document and replaces Tag names by using the
   * replacement configuration of a {@link org.opencms.workplace.tools.content.CmsTagReplaceSettings}
   * instance.
   * <p>
   *
   * Instances are reusable.
   * <p>
   *
   * @since 6.1.7
   *
   */
  public final class CmsTagReplaceParser extends CmsHtmlParser {
  
      /** A tag factory that is able to make tags invisible to visitors. */
      private final NodeFactory m_nodeFactory;
  
      /**
       * Boolean flag that is set to true if during last call to {@link #process(String, String)}
       * content was changed.
       */
      private boolean m_changedContent;
      /**
       * The settings to use for replacing tags.
       */
      private final CmsTagReplaceSettings m_settings;
  
      /**
       * Default constructor that turns echo on and uses the settings for replacing tags.
       * <p>
       *
       * @param settings the settings to use for tag replacement.
       */
      public CmsTagReplaceParser(CmsTagReplaceSettings settings) {
  
          // echo on
          super(true);
          m_settings = settings;
          CmsHtmlTagRemoveFactory nodeFactory = new CmsHtmlTagRemoveFactory();
          // add the removals of the settings to the tag factory:
          Iterator itDeleteTags = m_settings.getDeleteTags().iterator();
          while (itDeleteTags.hasNext()) {
              nodeFactory.addTagRemoval((Tag)itDeleteTags.next());
          }
          m_nodeFactory = nodeFactory;
  
      }
  
      /**
       * Overridden to also return the attributes of the Tag.
       * <p>
       *
       * @see org.opencms.util.CmsHtmlParser#getTagHtml(org.htmlparser.Tag)
       */
      @Override
      public String getTagHtml(Tag tag) {
  
          if (CmsStringUtil.isEmpty(tag.getTagName())) {
              return "";
          }
          StringBuffer result = new StringBuffer(32);
          result.append('<');
          // Tag name is the first "Attribute"...
          Iterator itAttributes = tag.getAttributesEx().iterator();
          while (itAttributes.hasNext()) {
              result.append(itAttributes.next().toString());
              // avoid trailing whitespaces like <H1 >
              // in 2nd run htmlparser 1.5 would turn the whitespace into an Attribute with null name
              if (itAttributes.hasNext()) {
                  result.append(' ');
              }
          }
          result.append('>');
          return result.toString();
      }
  
      /**
       * Extracts the text from the given html content, assuming the given html encoding.
       * <p>
       * Additionally tags are replaced / removed according to the configuration of this instance.
       * <p>
       *
       * <h3>Please note:</h3>
       * There are static process methods in the superclass that will not do the replacements /
       * removals. Don't mix them up with this method.
       * <p>
       *
       * @param html the content to extract the plain text from.
       *
       * @param encoding the encoding to use.
       *
       * @return the text extracted from the given html content.
       *
       * @throws ParserException if something goes wrong.
       */
      @Override
      public String process(String html, String encoding) throws ParserException {
  
          // clear from potential previous run:
          m_result = new StringBuffer();
          m_changedContent = false;
  
          // initialize a parser with the given charset
          Parser parser = new Parser();
          parser.setNodeFactory(m_nodeFactory);
          Lexer lexer = new Lexer();
          Page page = new Page(html, encoding);
          lexer.setPage(page);
          parser.setLexer(lexer);
          // process the page using the given visitor
          parser.visitAllNodesWith(this);
          // return the result
          return getResult();
      }
  
      /**
       * @see org.opencms.util.CmsHtmlParser#visitEndTag(org.htmlparser.Tag)
       */
      @Override
      public void visitEndTag(Tag tag) {
  
          boolean change = m_settings.replace(tag);
          if (change) {
              m_changedContent = true;
          }
          super.visitEndTag(tag);
      }
  
      /**
       * @see org.opencms.util.CmsHtmlParser#visitTag(org.htmlparser.Tag)
       */
      @Override
      public void visitTag(Tag tag) {
  
          boolean change = m_settings.replace(tag);
          if (change) {
              m_changedContent = true;
          }
          super.visitTag(tag);
      }
  
      /**
       * Returns the changedContent.
       * <p>
       *
       * @return the changedContent
       */
      public boolean isChangedContent() {
  
          return m_changedContent;
      }
  
  }
  