/**
* Copyright (C) 2013 Salzburg Research.
*
* 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 at.newmedialab.ldpath.template.engine;
import at.newmedialab.ldpath.api.backend.RDFBackend;
import at.newmedialab.ldpath.template.model.freemarker.TemplateNodeModel;
import at.newmedialab.ldpath.template.model.freemarker.TemplateStackModel;
import freemarker.cache.TemplateLoader;
import freemarker.template.Configuration;
import freemarker.template.DefaultObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import java.io.File;
import java.io.IOException;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* Add file description here!
* <p/>
* Author: Sebastian Schaffert
*/
public class TemplateEngine<Node> {
private Configuration freemarker;
private RDFBackend<Node> backend;
public TemplateEngine(RDFBackend<Node> backend) {
this.backend = backend;
freemarker = new Configuration();
freemarker.setObjectWrapper(new DefaultObjectWrapper());
}
/**
* Allow setting a different template loader. Custom template loaders can be implemented in addition to
* those provided by FreeMarker.
*
* @param loader
*/
public void setTemplateLoader(TemplateLoader loader) {
freemarker.setTemplateLoader(loader);
}
public void setDirectoryForTemplateLoading(File dir) throws IOException {
freemarker.setDirectoryForTemplateLoading(dir);
}
public void setServletContextForTemplateLoading(Object sctxt, String path) {
freemarker.setServletContextForTemplateLoading(sctxt, path);
}
public void setClassForTemplateLoading(Class clazz, String pathPrefix) {
freemarker.setClassForTemplateLoading(clazz, pathPrefix);
}
/**
* Process the template with the given name forn the given context node and write the result to the given
* output writer. The way the template is retrieved depends on the template loader, which can be set using the
* setTemplateLoader() method.
*
* @param context the initial context node to apply this template to
* @param templateName the name of the template
* @param out where to write the results
* @throws IOException
* @throws TemplateException
*/
public void processFileTemplate(Node context, String templateName, Writer out) throws IOException, TemplateException {
processTemplate(context,freemarker.getTemplate(templateName),null,out);
}
/**
* Process the template with the given name forn the given context node and write the result to the given
* output writer. The initial environment is passed over to the invocation of the template. The way the template
* is retrieved depends on the template loader, which can be set using the setTemplateLoader() method.
*
* @param context the initial context node to apply this template to
* @param templateName the name of the template
* @param initialEnv an initial root environment for processing the template
* @param out where to write the results
* @throws IOException
* @throws TemplateException
*/
public void processFileTemplate(Node context, String templateName, Map initialEnv, Writer out) throws IOException, TemplateException {
processTemplate(context,freemarker.getTemplate(templateName),initialEnv,out);
}
private void processTemplate(Node context, Template template, Map initialEnv, Writer out) throws IOException, TemplateException {
Map root = new HashMap();
if(initialEnv != null) {
for(Map.Entry entry : (Set<Map.Entry>) initialEnv.entrySet()) {
root.put(entry.getKey(), entry.getValue());
}
}
root.put("namespace", new NamespaceDirective());
root.put("evalLDPath",new LDPathMethod(backend));
root.put("ldpath",new LDPathDirective(backend));
TemplateStackModel contexts = new TemplateStackModel();
contexts.push(new TemplateNodeModel(context,backend));
root.put("context",contexts);
template.process(root,out);
}
}