/*
* Copyright 2004 Guy Van den Broeck
*
* Licensed 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 org.outerj.daisy.diff.helper;
import java.io.IOException;
import org.cyberneko.html.parsers.SAXParser;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
/**
* Parses HTML files using the Neko HTML parser. Puts all elements and attribute
* names to lowercase, removes all namespaces, produces well-formed XML.
*/
public class NekoHtmlParser {
public SaxBuffer parse(InputSource is) throws IOException, SAXException {
SaxBuffer buffer = new SaxBuffer();
parse(is, buffer);
return buffer;
}
public void parse(InputSource is, ContentHandler consumer)
throws IOException, SAXException {
if (is == null)
throw new NullPointerException("is argument is required.");
SAXParser parser = new SAXParser();
parser.setFeature("http://xml.org/sax/features/namespaces", true);
parser
.setFeature(
"http://cyberneko.org/html/features/override-namespaces",
false);
parser.setFeature(
"http://cyberneko.org/html/features/insert-namespaces", false);
parser
.setFeature(
"http://cyberneko.org/html/features/scanner/ignore-specified-charset",
true);
parser.setProperty(
"http://cyberneko.org/html/properties/default-encoding",
"UTF-8");
parser.setProperty("http://cyberneko.org/html/properties/names/elems",
"lower");
parser.setProperty("http://cyberneko.org/html/properties/names/attrs",
"lower");
parser.setContentHandler(new RemoveNamespacesHandler(
new MergeCharacterEventsHandler(consumer)));
parser.parse(is);
}
/**
* A ContentHandler that drops all namespace information.
*/
static class RemoveNamespacesHandler implements ContentHandler {
private ContentHandler consumer;
public RemoveNamespacesHandler(ContentHandler consumer) {
this.consumer = consumer;
}
public void endDocument() throws SAXException {
consumer.endDocument();
}
public void startDocument() throws SAXException {
consumer.startDocument();
}
public void characters(char ch[], int start, int length)
throws SAXException {
consumer.characters(ch, start, length);
}
public void ignorableWhitespace(char ch[], int start, int length)
throws SAXException {
consumer.ignorableWhitespace(ch, start, length);
}
public void endPrefixMapping(String prefix) throws SAXException {
// dropped on purpose
}
public void skippedEntity(String name) throws SAXException {
// dropped on purpose
}
public void setDocumentLocator(Locator locator) {
consumer.setDocumentLocator(locator);
}
public void processingInstruction(String target, String data)
throws SAXException {
// dropped on purpose
}
public void startPrefixMapping(String prefix, String uri)
throws SAXException {
// dropped on purpose
}
public void endElement(String namespaceURI, String localName,
String qName) throws SAXException {
consumer.endElement("", localName, localName);
}
public void startElement(String namespaceURI, String localName,
String qName, Attributes atts) throws SAXException {
AttributesImpl newAtts = new AttributesImpl(atts);
for (int i = 0; i < atts.getLength(); i++) {
newAtts.setURI(i, "");
newAtts.setQName(i, newAtts.getLocalName(i));
}
consumer.startElement("", localName, localName, atts);
}
}
}