freemarker.ext.dom.JaxenXPathSupport Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of freemarker Show documentation
Show all versions of freemarker Show documentation
FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
/*
* 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.
*/
package freemarker.ext.dom;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.jaxen.BaseXPath;
import org.jaxen.Function;
import org.jaxen.FunctionCallException;
import org.jaxen.FunctionContext;
import org.jaxen.JaxenException;
import org.jaxen.NamespaceContext;
import org.jaxen.Navigator;
import org.jaxen.UnresolvableException;
import org.jaxen.VariableContext;
import org.jaxen.XPathFunctionContext;
import org.jaxen.dom.DocumentNavigator;
import org.w3c.dom.Document;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import freemarker.core.CustomAttribute;
import freemarker.core.Environment;
import freemarker.template.ObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateBooleanModel;
import freemarker.template.TemplateDateModel;
import freemarker.template.TemplateException;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateNumberModel;
import freemarker.template.TemplateScalarModel;
import freemarker.template.utility.UndeclaredThrowableException;
/**
*/
class JaxenXPathSupport implements XPathSupport {
private static final CustomAttribute XPATH_CACHE_ATTR =
new CustomAttribute(CustomAttribute.SCOPE_TEMPLATE) {
@Override
protected Object create() {
return new HashMap();
}
};
// [2.4] Can't we just use Collections.emptyList()?
private final static ArrayList EMPTY_ARRAYLIST = new ArrayList();
@Override
public TemplateModel executeQuery(Object context, String xpathQuery) throws TemplateModelException {
try {
BaseXPath xpath;
Map xpathCache = (Map) XPATH_CACHE_ATTR.get();
synchronized (xpathCache) {
xpath = xpathCache.get(xpathQuery);
if (xpath == null) {
xpath = new BaseXPath(xpathQuery, FM_DOM_NAVIGATOR);
xpath.setNamespaceContext(customNamespaceContext);
xpath.setFunctionContext(FM_FUNCTION_CONTEXT);
xpath.setVariableContext(FM_VARIABLE_CONTEXT);
xpathCache.put(xpathQuery, xpath);
}
}
List result = xpath.selectNodes(context != null ? context : EMPTY_ARRAYLIST);
if (result.size() == 1) {
// [2.4] Use the proper object wrapper (argument in 2.4)
return ObjectWrapper.DEFAULT_WRAPPER.wrap(result.get(0));
}
NodeListModel nlm = new NodeListModel(result, null);
nlm.xpathSupport = this;
return nlm;
} catch (UndeclaredThrowableException e) {
Throwable t = e.getUndeclaredThrowable();
if (t instanceof TemplateModelException) {
throw (TemplateModelException) t;
}
throw e;
} catch (JaxenException je) {
throw new TemplateModelException(je);
}
}
static private final NamespaceContext customNamespaceContext = new NamespaceContext() {
@Override
public String translateNamespacePrefixToUri(String prefix) {
if (prefix.equals(Template.DEFAULT_NAMESPACE_PREFIX)) {
return Environment.getCurrentEnvironment().getDefaultNS();
}
return Environment.getCurrentEnvironment().getNamespaceForPrefix(prefix);
}
};
private static final VariableContext FM_VARIABLE_CONTEXT = new VariableContext() {
@Override
public Object getVariableValue(String namespaceURI, String prefix, String localName)
throws UnresolvableException {
try {
TemplateModel model = Environment.getCurrentEnvironment().getVariable(localName);
if (model == null) {
throw new UnresolvableException("Variable \"" + localName + "\" not found.");
}
if (model instanceof TemplateScalarModel) {
return ((TemplateScalarModel) model).getAsString();
}
if (model instanceof TemplateNumberModel) {
return ((TemplateNumberModel) model).getAsNumber();
}
if (model instanceof TemplateDateModel) {
return ((TemplateDateModel) model).getAsDate();
}
if (model instanceof TemplateBooleanModel) {
return Boolean.valueOf(((TemplateBooleanModel) model).getAsBoolean());
}
} catch (TemplateModelException e) {
throw new UndeclaredThrowableException(e);
}
throw new UnresolvableException(
"Variable \"" + localName + "\" exists, but it's not a string, number, date, or boolean");
}
};
private static final FunctionContext FM_FUNCTION_CONTEXT = new XPathFunctionContext() {
@Override
public Function getFunction(String namespaceURI, String prefix, String localName)
throws UnresolvableException {
try {
return super.getFunction(namespaceURI, prefix, localName);
} catch (UnresolvableException e) {
return super.getFunction(null, null, localName);
}
}
};
/**
* Stores the the template parsed as {@link Document} in the template itself.
*/
private static final CustomAttribute FM_DOM_NAVIAGOTOR_CACHED_DOM
= new CustomAttribute(CustomAttribute.SCOPE_TEMPLATE);
private static final Navigator FM_DOM_NAVIGATOR = new DocumentNavigator() {
@Override
public Object getDocument(String uri) throws FunctionCallException {
try {
Template raw = getTemplate(uri);
Document doc = (Document) FM_DOM_NAVIAGOTOR_CACHED_DOM.get(raw);
if (doc == null) {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder = factory.newDocumentBuilder();
FmEntityResolver er = new FmEntityResolver();
builder.setEntityResolver(er);
doc = builder.parse(createInputSource(null, raw));
// If the entity resolver got called 0 times, the document
// is standalone, so we can safely cache it
if (er.getCallCount() == 0) {
FM_DOM_NAVIAGOTOR_CACHED_DOM.set(doc, raw);
}
}
return doc;
} catch (Exception e) {
throw new FunctionCallException("Failed to parse document for URI: " + uri, e);
}
}
};
static Template getTemplate(String systemId) throws IOException {
Environment env = Environment.getCurrentEnvironment();
String encoding = env.getTemplate().getEncoding();
if (encoding == null) {
encoding = env.getConfiguration().getEncoding(env.getLocale());
}
String templatePath = env.getTemplate().getName();
int lastSlash = templatePath.lastIndexOf('/');
templatePath = lastSlash == -1 ? "" : templatePath.substring(0, lastSlash + 1);
systemId = env.toFullTemplateName(templatePath, systemId);
Template raw = env.getConfiguration().getTemplate(systemId, env.getLocale(), encoding, false);
return raw;
}
private static InputSource createInputSource(String publicId, Template raw) throws IOException, SAXException {
StringWriter sw = new StringWriter();
try {
raw.process(Collections.EMPTY_MAP, sw);
} catch (TemplateException e) {
throw new SAXException(e);
}
InputSource is = new InputSource();
is.setPublicId(publicId);
is.setSystemId(raw.getName());
is.setCharacterStream(new StringReader(sw.toString()));
return is;
}
private static class FmEntityResolver implements EntityResolver {
private int callCount = 0;
@Override
public InputSource resolveEntity(String publicId, String systemId)
throws SAXException, IOException {
++callCount;
return createInputSource(publicId, getTemplate(systemId));
}
int getCallCount() {
return callCount;
}
};
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy