/*
* eXist Open Source Native XML Database
* Copyright (C) 2016 The eXist Project
* http://exist-db.org
*
* This program 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
* of the License, or (at your option) any later version.
*
* This program 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.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.exist.util;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import com.evolvedbinary.j8fu.Either;
import org.xml.sax.*;
import java.util.Map;
import java.util.Optional;
/**
* @author Adam Retter
*/
public class HtmlToXmlParser {
private final static Logger LOG = LogManager.getLogger(HtmlToXmlParser.class);
public static final String HTML_TO_XML_PARSER_ELEMENT = "html-to-xml";
public static final String HTML_TO_XML_PARSER_CLASS_ATTRIBUTE = "class";
public static final String HTML_TO_XML_PARSER_PROPERTIES_ELEMENT = "properties";
public static final String HTML_TO_XML_PARSER_FEATURES_ELEMENT = "features";
public static final String HTML_TO_XML_PARSER_PROPERTY = "parser.html-to-xml-parser";
public static final String HTML_TO_XML_PARSER_PROPERTIES_PROPERTY = "parser.html-to-xml-parser.properties";
public static final String HTML_TO_XML_PARSER_FEATURES_PROPERTY = "parser.html-to-xml-parser.features";
public static final String PARSER_ELEMENT_NAME = "parser";
/**
* Returns the Configured HTML to XML parser
*
* @param config The configuration which specifies the classname of the parser to use
*
* @return If the configuration specifies a valid HTML to XML Parser and it
* is available on the classpath, then the result of instantiating it will be
* returned, otherwise {@link Optional#EMPTY}
*/
public static Optional<Either<Throwable, XMLReader>> getHtmlToXmlParser(final Configuration config) {
final Optional<String> parserClassName =
Optional.ofNullable((String)config.getProperty(HTML_TO_XML_PARSER_PROPERTY));
// instantiate the parser
final Optional<Either<Throwable, XMLReader>> inst = parserClassName.map(cn -> {
Either<Throwable, XMLReader> result;
try {
final Class clazz = Class.forName(cn);
if (XMLReader.class.isAssignableFrom(clazz)) {
final XMLReader reader = (XMLReader) clazz.newInstance();
final Map<String, Boolean> features = (Map<String, Boolean>)config.getProperty(HTML_TO_XML_PARSER_FEATURES_PROPERTY);
if(features != null) {
for(final Map.Entry<String, Boolean> feature : features.entrySet()) {
reader.setFeature(feature.getKey(), feature.getValue());
}
}
final Map<String, Object> properties = (Map<String, Object>)config.getProperty(HTML_TO_XML_PARSER_PROPERTIES_PROPERTY);
if(properties != null) {
for(final Map.Entry<String, Object> property : properties.entrySet()) {
reader.setProperty(property.getKey(), property.getValue());
}
}
result = Either.Right(reader);
} else {
result = Either.Left(new ClassCastException(cn + " does not implement org.xml.sax.XMLReader"));
}
} catch(final ClassNotFoundException | InstantiationException | IllegalAccessException | SAXNotRecognizedException | SAXNotSupportedException e) {
result = Either.Left(e);
}
return result;
});
return inst;
}
}