contrib/rss/src/main/java/org/apache/abdera/contrib/rss/RssChannel.java

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  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.  For additional information regarding
* copyright in this work, please see the NOTICE file in the top level
* directory of this distribution.
*/
package org.apache.abdera.contrib.rss;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Date;
import java.util.List;
import java.util.Map;

import javax.xml.namespace.QName;

import org.apache.abdera.Abdera;
import org.apache.abdera.factory.Factory;
import org.apache.abdera.i18n.iri.IRI;
import org.apache.abdera.model.Category;
import org.apache.abdera.model.DateTime;
import org.apache.abdera.model.Div;
import org.apache.abdera.model.Element;
import org.apache.abdera.model.ElementWrapper;
import org.apache.abdera.model.Entry;
import org.apache.abdera.model.ExtensibleElement;
import org.apache.abdera.model.ExtensibleElementWrapper;
import org.apache.abdera.model.Generator;
import org.apache.abdera.model.IRIElement;
import org.apache.abdera.model.Link;
import org.apache.abdera.model.Person;
import org.apache.abdera.model.Text;
import org.apache.abdera.model.Text.Type;
import org.apache.abdera.parser.stax.util.FOMElementIterator;
import org.apache.abdera.parser.stax.util.FOMHelper;
import org.apache.abdera.parser.stax.util.FOMList;
import org.apache.abdera.util.Constants;
import org.apache.abdera.xpath.XPath;
import org.apache.abdera.xpath.XPathException;

public class RssChannel 
  extends ExtensibleElementWrapper {

  public RssChannel(Element internal) {
    super(internal);
  }

  public RssChannel(Factory factory, QName qname) {
    super(factory, qname);
  }

  public void addEntry(Entry entry) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Entry addEntry() {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public List<Entry> getEntries() {
    QName qname = getQName();
    if (qname.getNamespaceURI().equals(RssConstants.RSS1_NS) &&
        qname.getLocalPart().equals("channel")) {
      List<Entry> entries = new ArrayList<Entry>();
      ExtensibleElement items = getExtension(RssConstants.QNAME_RDF_ITEMS);
      if (items != null) {
        ExtensibleElement se = items.getExtension(RssConstants.QNAME_RDF_SEQ);
        if (se != null) {
          List<Element> seq = se.getExtensions(RssConstants.QNAME_RDF_LI);
          for (Element el : seq) {
            String res = el.getAttributeValue("resource");
            if (res != null) {
              String path = "//rss:item[@rdf:about='" + res + "']";
              Element entryel = null;
              try {
                entryel = locate(path);
              } catch (Exception e) {}
              if (entryel != null) {
                //TODO:fix this.. entryel should already be an RssItem
                entries.add(new RssItem(entryel));
              }
            }
          }
        }
      }
      return entries;
    } else {
      return getExtensions(RssConstants.QNAME_ITEM);
    }
  }

  public Entry getEntry(String id) {
    if (id == null) return null;
    List<Entry> l = getEntries();
    for (Entry e : l) {
      IRI eid = e.getId();
      if (eid != null && eid.equals(new IRI(id))) return e;
    }
    return null;
  }

  public void insertEntry(Entry entry) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Entry insertEntry() {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void sortEntries(Comparator<Entry> comparator) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void sortEntriesByEdited(boolean new_first) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void sortEntriesByUpdated(boolean new_first) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void addAuthor(Person person) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Person addAuthor(String name) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Person addAuthor(String name, String email, String iri) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void addCategory(Category category) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Category addCategory(String term) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Category addCategory(String scheme, String term, String label) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void addLink(Link link) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Link addLink(String href) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Link addLink(String href, String rel) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Link addLink(String href, String rel, String type, String title,
      String hreflang, long length) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Link getAlternateLink() {
    Link link = getExtension(RssConstants.QNAME_LINK);
    if (link == null) link = getExtension(RssConstants.QNAME_RDF_LINK);
    return link;
  }

  public Link getAlternateLink(String type, String hreflang){
    return getAlternateLink();
  }

  public IRI getAlternateLinkResolvedHref() {
    Link link = getAlternateLink();
    return (link != null) ? link.getResolvedHref() : null;
  }

  public IRI getAlternateLinkResolvedHref(String type, String hreflang){
    return getAlternateLinkResolvedHref();
  }

  public Person getAuthor() {
    Person person = getExtension(RssConstants.QNAME_MANAGINGEDITOR);
    if (person == null) person = getExtension(RssConstants.QNAME_DC_CREATOR);
    return person;
  }

  public List<Person> getAuthors() {
    List<Person> people = getExtensions(RssConstants.QNAME_MANAGINGEDITOR);
    if (people == null || people.size() == 0) people = getExtensions(RssConstants.QNAME_DC_CREATOR);
    return people;
  }
  
  public List<Person> getContributors() {
    List<Person> people = getExtensions(RssConstants.QNAME_DC_CONTRIBUTOR);
    return people;
  }

  public List<Category> getCategories() {
    List<Category> cats = getExtensions(RssConstants.QNAME_CATEGORY);
    if (cats == null || cats.size() == 0) cats = getExtensions(RssConstants.QNAME_DC_SUBJECT);
    return cats;
  }

  @SuppressWarnings("unchecked")
  public List<Category> getCategories(String scheme) {
    return (scheme != null) ? 
      new FOMList<Category>(
        new FOMElementIterator(getInternal(), RssCategory.class, new QName("domain"), scheme, null)
      ) : getCategories();
  }

  public Generator getGenerator() {
    return getExtension(RssConstants.QNAME_GENERATOR);
  }

  public IRI getIcon() {
    IRIElement iri = getIconElement();
    return (iri != null) ? iri.getValue() : null;
  }

  public IRIElement getIconElement() {
    return getLogoElement();
  }

  public IRI getId() {
    IRIElement id = getIdElement();
    return (id != null) ? id.getValue() : null;
  }

  public IRIElement getIdElement() {
    return getExtension(RssConstants.QNAME_DC_IDENTIFIER);
  }

  public Link getLink(String rel) {
    if (rel.equals(Link.REL_ALTERNATE) || rel.equals(Link.REL_ALTERNATE_IANA)) {
      RssGuid guid = (RssGuid) getIdElement();
      if (guid != null && guid.isPermalink()) return guid;
      return getAlternateLink();
    }
    List<Link> links = FOMHelper.getLinks(getInternal(), rel);
    return (links != null && links.size() > 0) ? links.get(0) : null;
  }

  public IRI getLinkResolvedHref(String rel) {
    Link link = getLink(rel);
    return (link != null) ? link.getResolvedHref() : null;
  }

  public List<Link> getLinks() {
    return getExtensions(Constants.LINK);
  }

  public List<Link> getLinks(String rel) {
    return FOMHelper.getLinks(getInternal(), rel);
  }

  public List<Link> getLinks(String... rel) {
    return FOMHelper.getLinks(getInternal(), rel);
  }

  public IRI getLogo() {
    IRIElement iri = getLogoElement();
    return (iri != null) ? iri.getValue() : null;
  }

  public IRIElement getLogoElement() {
    
    IRIElement iri = getExtension(RssConstants.QNAME_IMAGE);
    if (iri == null) {
      Element image = getExtension(RssConstants.QNAME_RDF_IMAGE);
      if (image != null) {
        String id = image.getAttributeValue(RssConstants.QNAME_RDF_RESOURCE);
        if (id != null) {
          String path = "//rss:image[@rdf:about='" + id + "']";
          Element res = null;
          try {
            res = locate(path);
          } catch (Exception e) {
            e.printStackTrace();
          }
          if (res != null) {
            // TODO: Need to fix
            return new RssImage(res);
          }
        } else {
          return (IRIElement) image;
        }
      }
      
    }
    return iri;
  }

  public String getRights() {
    Text text = getRightsElement();
    return (text != null) ? text.getValue() : null;
  }

  public Text getRightsElement() {
    Text text = getExtension(RssConstants.QNAME_COPYRIGHT);
    if (text == null) text = getExtension(RssConstants.QNAME_DC_RIGHTS);
    return text;
  }

  public Type getRightsType() {
    Text text = getRightsElement();
    return (text != null) ? text.getTextType() : null;
  }

  public Link getSelfLink() {
    return getLink("self");
  }

  public IRI getSelfLinkResolvedHref() {
    Link link = getSelfLink();
    return (link != null) ? link.getResolvedHref() : null;
  }

  public String getSubtitle() {
    Text text = getSubtitleElement();
    return (text != null) ? text.getValue() : null;
  }

  public Text getSubtitleElement() {
    Text text = getExtension(RssConstants.QNAME_DESCRIPTION);
    if (text == null) text = getExtension(RssConstants.QNAME_RDF_DESCRIPTION);
    if (text == null) text = getExtension(RssConstants.QNAME_DC_DESCRIPTION);
    return text;
  }

  public Type getSubtitleType() {
    Text text = getSubtitleElement();
    return (text != null) ? text.getTextType() : null;
  }

  public String getTitle() {
    Text text = getTitleElement();
    return (text != null) ? text.getValue() : null;
  }

  public Text getTitleElement() {
    Text text = getExtension(RssConstants.QNAME_TITLE);
    if (text == null) text = getExtension(RssConstants.QNAME_RDF_TITLE);
    if (text == null) text = getExtension(RssConstants.QNAME_DC_TITLE);
    return text;
  }

  public Type getTitleType() {
    Text text = getTitleElement();
    return (text != null) ? text.getTextType() : null;
  }

  public Date getUpdated() {
    DateTime dt = getUpdatedElement();
    return (dt != null) ? dt.getDate() : null;
  }

  public DateTime getUpdatedElement() {
    DateTime dt = getExtension(RssConstants.QNAME_LASTBUILDDATE);
    if (dt == null) dt = getExtension(RssConstants.QNAME_LASTBUILDDATE2);
    if (dt == null) dt = getExtension(RssConstants.QNAME_PUBDATE);
    if (dt == null) dt = getExtension(RssConstants.QNAME_PUBDATE2);
    if (dt == null) dt = getExtension(RssConstants.QNAME_DC_DATE);
    return dt;
  }

  public String getUpdatedString() {
    DateTime dt = getUpdatedElement();
    return (dt != null) ? dt.getString() : null;
  }
  
  public Date getPublished() {
    DateTime dt = getPublishedElement();
    return (dt != null) ? dt.getDate() : null;
  }

  public DateTime getPublishedElement() {
    DateTime dt = getExtension(RssConstants.QNAME_PUBDATE);
    if (dt == null) dt = getExtension(RssConstants.QNAME_PUBDATE2);
    if (dt == null) dt = getExtension(RssConstants.QNAME_DC_DATE);
    return dt;
  }

  public String getPublishedString() {
    DateTime dt = getPublishedElement();
    return (dt != null) ? dt.getString() : null;
  }

  public IRIElement newId() {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setGenerator(Generator generator) { 
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Generator setGenerator(String iri, String version, String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public IRIElement setIcon(String iri) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setIconElement(IRIElement iri) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public IRIElement setId(String id) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public IRIElement setId(String id, boolean normalize) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setIdElement(IRIElement id) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public IRIElement setLogo(String iri) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setLogoElement(IRIElement iri) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setRights(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setRights(String value, Type type) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setRights(Div value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setRightsAsHtml(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setRightsAsXhtml(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setRightsElement(Text text) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setSubtitle(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setSubtitle(String value, Type type) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setSubtitle(Div value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setSubtitleAsHtml(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setSubtitleAsXhtml(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setSubtitleElement(Text text) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setTitle(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setTitle(String value, Type type) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setTitle(Div value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setTitleAsHtml(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public Text setTitleAsXhtml(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setTitleElement(Text text) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public DateTime setUpdated(Date value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public DateTime setUpdated(String value) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public void setUpdatedElement(DateTime dateTime) {
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  public String getLanguage() {
    String lang = getSimpleExtension(RssConstants.QNAME_LANGUAGE);
    if (lang == null) lang = getSimpleExtension(RssConstants.QNAME_DC_LANGUAGE);
    return lang;
  }

  public <T extends Element>T setLanguage(String language) {  
    throw new UnsupportedOperationException("Modifications are not allowed");
  }

  private Element locate(String path) throws XPathException {
    Abdera abdera = this.getFactory().getAbdera();
    XPath xpath = abdera.getXPath();
    Map<String,String> ns = xpath.getDefaultNamespaces();
    ns.put("rdf", RssConstants.RDF_NS);
    ns.put("rss", RssConstants.RSS1_NS);
    Element el = getDocument().getRoot();
    if (el instanceof ElementWrapper) {
      el = ((ElementWrapper)el).getInternal();
    }
    return (Element) xpath.selectSingleNode(path,el,ns);
  }
}