001/*
002    Licensed to the Apache Software Foundation (ASF) under one
003    or more contributor license agreements.  See the NOTICE file
004    distributed with this work for additional information
005    regarding copyright ownership.  The ASF licenses this file
006    to you under the Apache License, Version 2.0 (the
007    "License"); you may not use this file except in compliance
008    with the License.  You may obtain a copy of the License at
009
010       http://www.apache.org/licenses/LICENSE-2.0
011
012    Unless required by applicable law or agreed to in writing,
013    software distributed under the License is distributed on an
014    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015    KIND, either express or implied.  See the License for the
016    specific language governing permissions and limitations
017    under the License.
018 */
019package org.apache.wiki.render;
020
021import org.apache.log4j.Logger;
022import org.apache.wiki.WikiContext;
023import org.apache.wiki.parser.WikiDocument;
024import org.jdom2.Text;
025import org.jdom2.xpath.XPathFactory;
026
027import java.io.IOException;
028import java.util.List;
029
030
031/**
032 *  A simple renderer that just renders all the text() nodes from the DOM tree.
033 *  This is very useful for cleaning away all of the XHTML.
034 *
035 *  @since  2.4
036 */
037public class CleanTextRenderer extends WikiRenderer {
038
039    private static final String ALL_TEXT_NODES = "//text()";
040    private static final Logger log = Logger.getLogger( CleanTextRenderer.class );
041
042    /**
043     *  Create a renderer.
044     *
045     *  @param context A WikiContext in which the rendering will take place.
046     *  @param doc The WikiDocument which shall be rendered.
047     */
048    public CleanTextRenderer( final WikiContext context, final WikiDocument doc ) {
049        super( context, doc );
050    }
051
052    /**
053     *  {@inheritDoc}
054     */
055    public String getString() throws IOException {
056        final StringBuilder sb = new StringBuilder();
057        try {
058            final List< ? > nodes = XPathFactory.instance().compile( ALL_TEXT_NODES ).evaluate( m_document.getDocument() );
059            for( final Object el : nodes ) {
060                if( el instanceof Text ) {
061                    sb.append( ( ( Text )el ).getValue() );
062                }
063            }
064        } catch( final IllegalStateException e ) {
065            log.error("Could not parse XPATH expression");
066            throw new IOException( e.getMessage(), e );
067        }
068
069        return sb.toString();
070    }
071
072}