/*
* =============================================================================
*
* Copyright (c) 2011-2013, The THYMELEAF team (http://www.thymeleaf.org)
*
* 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.thymeleaf.templateparser.html;
import java.io.Reader;
import java.io.StringReader;
import java.util.List;
import org.apache.xerces.parsers.DOMParser;
import org.cyberneko.html.HTMLConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.thymeleaf.Configuration;
import org.thymeleaf.dom.Document;
import org.thymeleaf.dom.Node;
import org.thymeleaf.exceptions.ConfigurationException;
import org.thymeleaf.exceptions.TemplateInputException;
import org.thymeleaf.exceptions.TemplateProcessingException;
import org.thymeleaf.templateparser.EntityResolver;
import org.thymeleaf.templateparser.ErrorHandler;
import org.thymeleaf.templateparser.ITemplateParser;
import org.thymeleaf.templateparser.TemplatePreprocessingReader;
import org.thymeleaf.util.ResourcePool;
import org.thymeleaf.util.StandardDOMTranslator;
import org.xml.sax.InputSource;
// NOTE: This is a slightly modified class. The nasty class loader stuff is removed to not break on OSGi.
/**
* <p>
* Document parser implementation for non-XML HTML documents.
* </p>
*
* @since 2.0.0
*
* @author Daniel Fernández
*/
public abstract class AbstractHtmlTemplateParser implements ITemplateParser {
private static final int BUFFER_SIZE = 8192;
private final String templateModeName;
private final NekoBasedHtmlParser parser;
protected AbstractHtmlTemplateParser(final String templateModeName, final int poolSize) {
this.templateModeName = templateModeName;
parser = new NekoBasedHtmlParser(poolSize);
}
public final Document parseTemplate(final Configuration configuration, final String documentName, final Reader reader) {
return this.parser.parseTemplate(configuration, documentName, getTemplatePreprocessingReader(reader));
}
public final List<Node> parseFragment(final Configuration configuration, final String fragment) {
final String wrappedFragment = wrapFragment(fragment);
final Document document =
parseTemplate(
configuration,
null, // documentName
new StringReader(wrappedFragment));
return unwrapFragment(document);
}
protected abstract String wrapFragment(final String fragment);
protected abstract List<Node> unwrapFragment(final Document document);
/*
* This is defined in a class apart so that the classloader does not always try to load
* neko and xerces classes that might not be in the classpath.
*/
private static class NekoBasedHtmlParser {
private final Logger logger = LoggerFactory.getLogger(this.getClass());
// The org.apache.xerces.parsers.DOMParser is not used here as a type
// parameter to avoid the class loader to try to load this xerces class
// (and fail) before we control the error at the constructor.
private final ResourcePool<Object> pool;
private boolean canResetParsers = true;
private NekoBasedHtmlParser(final int poolSize) {
super();
this.pool = new ResourcePool<Object>(new HtmlTemplateParserFactory(), poolSize);
}
public final Document parseTemplate(final Configuration configuration, final String documentName,
final TemplatePreprocessingReader templateReader) {
final DOMParser domParser = (DOMParser) this.pool.allocate();
try {
domParser.setErrorHandler(ErrorHandler.INSTANCE);
domParser.setEntityResolver(new EntityResolver(configuration));
domParser.parse(new InputSource(templateReader));
final org.w3c.dom.Document domDocument = domParser.getDocument();
if (this.canResetParsers) {
try {
/*
* Reset the parser so that it can be used again.
*/
domParser.reset();
} catch (final UnsupportedOperationException ignored) {
if (this.logger.isWarnEnabled()) {
this.logger.warn(
"[THYMELEAF] The HTML Parser implementation being used (\"{}\") does not implement " +
"the \"reset\" operation. This will force Thymeleaf to re-create parser instances " +
"each time they are needed for parsing templates, which is more costly. Enabling template " +
"cache is recommended, and also using a parser library which implements \"reset\" such as " +
"nekoHTML version 1.9.15 or newer.",
domParser.getClass().getName());
}
this.canResetParsers = false;
}
}
return StandardDOMTranslator.translateDocument(domDocument, documentName, templateReader.getDocTypeClause());
} catch (final TemplateProcessingException e) {
throw e;
} catch (final Exception e) {
throw new TemplateInputException("Exception parsing document", e);
} finally {
if (templateReader != null) {
try {
templateReader.close();
} catch (final Exception ignored) {
// ignored
}
}
if (this.canResetParsers) {
this.pool.release(domParser);
} else {
this.pool.discardAndReplace(domParser);
}
}
}
}
static class HtmlTemplateParserFactory implements ResourcePool.IResourceFactory<Object> {
HtmlTemplateParserFactory() {
super();
}
public Object createResource() {
try {
final HTMLConfiguration config = new HTMLConfiguration();
config.setFeature("http://xml.org/sax/features/namespaces", false);
config.setFeature("http://cyberneko.org/html/features/override-doctype", true);
config.setFeature("http://cyberneko.org/html/features/scanner/cdata-sections", true);
// Avoids the inclusion of <HTML><BODY>, etc. around template fragments. Tag balancing will only
// be performed inside the fragments' root nodes.
config.setFeature("http://cyberneko.org/html/features/balance-tags/document-fragment", true);
config.setProperty("http://cyberneko.org/html/properties/doctype/pubid", "");
config.setProperty("http://cyberneko.org/html/properties/doctype/sysid", "");
config.setProperty("http://cyberneko.org/html/properties/names/elems", "match");
config.setProperty("http://cyberneko.org/html/properties/names/attrs", "no-change");
return new DOMParser(config);
} catch(final Exception e) {
throw new ConfigurationException(
"Error while creating nekoHTML-based parser for " +
"LEGACYHTML5 template modes.", e);
}
}
}
/**
* @since 2.0.11
*/
protected boolean shouldAddThymeleafRootToParser() {
return false;
}
/**
* @since 2.0.11
*/
protected TemplatePreprocessingReader getTemplatePreprocessingReader(final Reader reader) {
if (reader instanceof TemplatePreprocessingReader) {
final TemplatePreprocessingReader templatePreprocessingReader = (TemplatePreprocessingReader) reader;
return new TemplatePreprocessingReader(
templatePreprocessingReader.getInnerReader(), BUFFER_SIZE, shouldAddThymeleafRootToParser());
}
return new TemplatePreprocessingReader(reader, BUFFER_SIZE, shouldAddThymeleafRootToParser());
}
}