/*
* Copyright 2004 Sun Microsystems, Inc.
*
* 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 com.rometools.rome.io.impl;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Set;
import org.jdom2.Attribute;
import org.jdom2.Element;
import org.jdom2.Namespace;
import com.rometools.rome.feed.module.DCModule;
import com.rometools.rome.feed.module.DCSubject;
import com.rometools.rome.feed.module.Module;
import com.rometools.rome.io.ModuleGenerator;
/**
* Feed Generator for DublinCore Module.
* <p/>
*
* @author Elaine Chien
*
*/
public class DCModuleGenerator implements ModuleGenerator {
private static final String DC_URI = "http://purl.org/dc/elements/1.1/";
private static final String TAXO_URI = "http://purl.org/rss/1.0/modules/taxonomy/";
private static final String RDF_URI = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
private static final Namespace DC_NS = Namespace.getNamespace("dc", DC_URI);
private static final Namespace TAXO_NS = Namespace.getNamespace("taxo", TAXO_URI);
private static final Namespace RDF_NS = Namespace.getNamespace("rdf", RDF_URI);
private static final Set<Namespace> NAMESPACES;
static {
final Set<Namespace> nss = new HashSet<Namespace>();
nss.add(DC_NS);
nss.add(TAXO_NS);
nss.add(RDF_NS);
NAMESPACES = Collections.unmodifiableSet(nss);
}
@Override
public final String getNamespaceUri() {
return DC_URI;
}
private final Namespace getDCNamespace() {
return DC_NS;
}
private final Namespace getRDFNamespace() {
return RDF_NS;
}
private final Namespace getTaxonomyNamespace() {
return TAXO_NS;
}
/**
* Returns a set with all the URIs (JDOM Namespace elements) this module generator uses.
* <p/>
* It is used by the the feed generators to add their namespace definition in the root element
* of the generated document (forward-missing of Java 5.0 Generics).
* <p/>
*
* @return a set with all the URIs this module generator uses.
*/
@Override
public final Set<Namespace> getNamespaces() {
return NAMESPACES;
}
/**
* Populate an element tree with elements for a module.
* <p>
*
* @param module the module to populate from.
* @param element the root element to attach child elements to.
*/
@Override
public final void generate(final Module module, final Element element) {
final DCModule dcModule = (DCModule) module;
final String title = dcModule.getTitle();
if (title != null) {
element.addContent(generateSimpleElementList("title", dcModule.getTitles()));
}
final String creator = dcModule.getCreator();
if (creator != null) {
element.addContent(generateSimpleElementList("creator", dcModule.getCreators()));
}
final List<DCSubject> subjects = dcModule.getSubjects();
for (final DCSubject dcSubject : subjects) {
element.addContent(generateSubjectElement(dcSubject));
}
final String description = dcModule.getDescription();
if (description != null) {
element.addContent(generateSimpleElementList("description", dcModule.getDescriptions()));
}
final String publisher = dcModule.getPublisher();
if (publisher != null) {
element.addContent(generateSimpleElementList("publisher", dcModule.getPublishers()));
}
final List<String> contributors = dcModule.getContributors();
if (contributors != null) {
element.addContent(generateSimpleElementList("contributor", contributors));
}
final Date dcDate = dcModule.getDate();
if (dcDate != null) {
for (final Date date : dcModule.getDates()) {
element.addContent(generateSimpleElement("date", DateParser.formatW3CDateTime(date, Locale.US)));
}
}
final String type = dcModule.getType();
if (type != null) {
element.addContent(generateSimpleElementList("type", dcModule.getTypes()));
}
final String format = dcModule.getFormat();
if (format != null) {
element.addContent(generateSimpleElementList("format", dcModule.getFormats()));
}
final String identifier = dcModule.getIdentifier();
if (identifier != null) {
element.addContent(generateSimpleElementList("identifier", dcModule.getIdentifiers()));
}
final String source = dcModule.getSource();
if (source != null) {
element.addContent(generateSimpleElementList("source", dcModule.getSources()));
}
final String language = dcModule.getLanguage();
if (language != null) {
element.addContent(generateSimpleElementList("language", dcModule.getLanguages()));
}
final String relation = dcModule.getRelation();
if (relation != null) {
element.addContent(generateSimpleElementList("relation", dcModule.getRelations()));
}
final String coverage = dcModule.getCoverage();
if (coverage != null) {
element.addContent(generateSimpleElementList("coverage", dcModule.getCoverages()));
}
final String rights = dcModule.getRights();
if (rights != null) {
element.addContent(generateSimpleElementList("rights", dcModule.getRightsList()));
}
}
/**
* Utility method to generate an element for a subject.
* <p>
*
* @param subject the subject to generate an element for.
* @return the element for the subject.
*/
protected final Element generateSubjectElement(final DCSubject subject) {
final Element subjectElement = new Element("subject", getDCNamespace());
final String taxonomyUri = subject.getTaxonomyUri();
final String value = subject.getValue();
if (taxonomyUri != null) {
final Attribute resourceAttribute = new Attribute("resource", taxonomyUri, getRDFNamespace());
final Element topicElement = new Element("topic", getTaxonomyNamespace());
topicElement.setAttribute(resourceAttribute);
final Element descriptionElement = new Element("Description", getRDFNamespace());
descriptionElement.addContent(topicElement);
if (value != null) {
final Element valueElement = new Element("value", getRDFNamespace());
valueElement.addContent(value);
descriptionElement.addContent(valueElement);
}
subjectElement.addContent(descriptionElement);
} else {
subjectElement.addContent(value);
}
return subjectElement;
}
/**
* Utility method to generate a single element containing a string.
* <p>
*
* @param name the name of the elment to generate.
* @param value the value of the text in the element.
* @return the element generated.
*/
protected final Element generateSimpleElement(final String name, final String value) {
final Element element = new Element(name, getDCNamespace());
element.addContent(value);
return element;
}
/**
* Utility method to generate a list of simple elements.
* <p>
*
* @param name the name of the element list to generate.
* @param values the list of values for the elements.
* @return a list of Elements created.
*/
protected final List<Element> generateSimpleElementList(final String name, final List<String> values) {
final List<Element> elements = new ArrayList<Element>();
for (final String value : values) {
elements.add(generateSimpleElement(name, value));
}
return elements;
}
}