package org.apache.commons.digester3.examples.api.documentmarkup;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.
*/
import org.apache.commons.digester3.Digester;
import org.apache.commons.digester3.Rule;
import java.util.List;
import javax.xml.parsers.SAXParser;
import org.xml.sax.XMLReader;
import org.xml.sax.SAXException;
import org.xml.sax.Attributes;
/**
* This is a subclass of digester which supports rules which implement
* the TextSegmentHandler interface, causing the "textSegment" method
* on each matching rule (of the appropriate type) to be invoked when
* an element contains a segment of text followed by a child element.
* <p>
* See the readme file included with this example for more information.
*/
public class MarkupDigester
extends Digester
{
/** See equivalent constructor in Digester class. */
public MarkupDigester()
{
}
/** See equivalent constructor in Digester class. */
public MarkupDigester( SAXParser parser )
{
super( parser );
}
/** See equivalent constructor in Digester class. */
public MarkupDigester( XMLReader reader )
{
super( reader );
}
//===================================================================
/**
* The text found in the current element since the last child element.
*/
protected StringBuilder currTextSegment = new StringBuilder();
/**
* Process notification of character data received from the body of
* an XML element.
*
* @param buffer The characters from the XML document
* @param start Starting offset into the buffer
* @param length Number of characters from the buffer
*
* @exception SAXException if a parsing error is to be reported
*/
@Override
public void characters( char buffer[], int start, int length )
throws SAXException
{
super.characters( buffer, start, length );
currTextSegment.append( buffer, start, length );
}
/**
* Process notification of the start of an XML element being reached.
*
* @param namespaceURI The Namespace URI, or the empty string if the element
* has no Namespace URI or if Namespace processing is not being performed.
* @param localName The local name (without prefix), or the empty
* string if Namespace processing is not being performed.
* @param qName The qualified name (with prefix), or the empty
* string if qualified names are not available.
* @param list The attributes attached to the element. If there are
* no attributes, it shall be an empty Attributes object.
* @exception SAXException if a parsing error is to be reported
*/
@Override
public void startElement( String namespaceURI, String localName, String qName, Attributes list )
throws SAXException
{
handleTextSegments();
// Unlike bodyText, which accumulates despite intervening child
// elements, currTextSegment gets cleared here. This means that
// we don't need to save it on a stack either.
currTextSegment.setLength( 0 );
super.startElement( namespaceURI, localName, qName, list );
}
/**
* Process notification of the end of an XML element being reached.
*
* @param namespaceURI - The Namespace URI, or the empty string if the
* element has no Namespace URI or if Namespace processing is not
* being performed.
* @param localName - The local name (without prefix), or the empty
* string if Namespace processing is not being performed.
* @param qName - The qualified XML 1.0 name (with prefix), or the
* empty string if qualified names are not available.
* @exception SAXException if a parsing error is to be reported
*/
@Override
public void endElement( String namespaceURI, String localName, String qName )
throws SAXException
{
handleTextSegments();
currTextSegment.setLength( 0 );
super.endElement( namespaceURI, localName, qName );
}
/**
* Iterate over the list of rules most recently matched, and
* if any of them implement the TextSegmentHandler interface then
* invoke that rule's textSegment method passing the current
* segment of text from the xml element body.
*/
private void handleTextSegments()
throws SAXException
{
if ( currTextSegment.length() > 0 )
{
String segment = currTextSegment.toString();
List<Rule> parentMatches = getMatches().peek();
int len = parentMatches.size();
for ( int i = 0; i < len; ++i )
{
Rule r = parentMatches.get( i );
if ( r instanceof TextSegmentHandler )
{
TextSegmentHandler h = (TextSegmentHandler) r;
try
{
h.textSegment( segment );
}
catch ( Exception e )
{
throw createSAXException( e );
}
}
}
}
}
}