/*
* FeedRepresentation.java
*
* Created on March 27, 2007, 11:55 PM
*
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
*/
package org.atomojo.app;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URLDecoder;
import java.util.Date;
import java.util.Iterator;
import java.util.logging.Level;
import org.atomojo.app.db.Entry;
import org.atomojo.app.db.Feed;
import org.atomojo.app.db.Term;
import org.atomojo.app.db.TermInstance;
import org.infoset.xml.DocumentLoader;
import org.infoset.xml.Element;
import org.infoset.xml.InfosetFactory;
import org.infoset.xml.ItemConstructor;
import org.infoset.xml.ItemDestination;
import org.infoset.xml.Name;
import org.infoset.xml.XMLException;
import org.infoset.xml.filter.RemoveDocumentFilter;
import org.infoset.xml.sax.SAXDocumentLoader;
import org.infoset.xml.util.WriterItemDestination;
import org.restlet.data.CharacterSet;
import org.restlet.data.Form;
import org.restlet.data.MediaType;
import org.restlet.data.Reference;
import org.restlet.representation.OutputRepresentation;
import org.restlet.representation.Representation;
import org.restlet.resource.ServerResource;
/**
*
* @author alex
*/
public class TermResource extends ServerResource {
static final URI CHILD_TERM = URI.create("http://www.atomojo.org/O/relations/child");
static final URI ANCESTOR_TERM = URI.create("http://www.atomojo.org/O/relations/ancestor");
Reference resourceBase;
App app;
URI term;
/** Creates a new instance of FeedRepresentation */
public TermResource(Reference resourceBase,App app,URI term) {
setNegotiated(false);
this.resourceBase = resourceBase;
this.app = app;
this.term = term;
}
public Representation get() {
return new OutputRepresentation(MediaType.APPLICATION_ATOM_XML) {
public void write(OutputStream os)
throws IOException
{
setCharacterSet(CharacterSet.UTF_8);
try {
Form form = getRequest().getResourceRef().getQueryAsForm();
String value = form.getFirstValue("value");
generate(new WriterItemDestination(new OutputStreamWriter(os,"UTF-8"),"UTF-8"),value);
} catch (XMLException ex) {
getContext().getLogger().log(Level.SEVERE,"Cannot serialize metadata feed.",ex);
throw new IOException("Cannot serialize metadata feed: "+ex.getMessage());
}
}
};
}
public void generate(ItemDestination dest,String value)
throws XMLException
{
//getContext().getLogger().info("Generating feed for term "+term);
ItemConstructor constructor = InfosetFactory.getDefaultInfoset().createItemConstructor();
dest.send(constructor.createDocument());
dest.send(constructor.createElement(AtomResource.FEED_NAME));
dest.send(constructor.createCharacters("\n"));
link(constructor,dest,"self",getRequest().getResourceRef().toString());
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.TITLE_NAME,"Term "+term);
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.ID_NAME,getRequest().getResourceRef().toString());
dest.send(constructor.createCharacters("\n"));
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(new Date()));
term(constructor,dest,term,null);
try {
Term dbTerm = app.getDB().findTerm(term);
if (dbTerm!=null) {
Iterator<TermInstance<Feed>> feeds = app.getDB().getFeedsByTerm(dbTerm,value);
while (feeds.hasNext()) {
TermInstance<Feed> termValue = feeds.next();
Feed feed = termValue.getTarget();
dest.send(constructor.createCharacters("\n"));
dest.send(constructor.createElement(AtomResource.ENTRY_NAME));
text(constructor,dest,AtomResource.ID_NAME,feed.getUUID().toString());
text(constructor,dest,AtomResource.PUBLISHED_NAME,AtomResource.toXSDDate(feed.getCreated()));
text(constructor,dest,AtomResource.UPDATED_NAME,AtomResource.toXSDDate(feed.getEdited()));
text(constructor,dest,AtomResource.TITLE_NAME,app.getStorage().getFeedTitle(feed.getPath(),feed.getUUID()));
term(constructor,dest,Categorization.FEED_TYPE_TERM,null);
Iterator<TermInstance<Feed>> terms = feed.getTerms();
while (terms.hasNext()) {
TermInstance<Feed> fterm = terms.next();
term(constructor,dest,fterm.getTerm().getURI(),fterm.getValue());
}
link(constructor,dest,"related",resourceBase+feed.getPath());
dest.send(constructor.createElementEnd(AtomResource.ENTRY_NAME));
}
DocumentLoader loader = new SAXDocumentLoader();
Iterator<TermInstance<Entry>> entries = app.getDB().getEntriesByTerm(dbTerm,value);
while (entries.hasNext()) {
TermInstance<Entry> termValue = entries.next();
Entry entry = termValue.getTarget();
Feed feed = entry.getFeed();
String feedPath = feed.getPath();
String feedBaseURI = resourceBase.toString()+feedPath;
dest.send(constructor.createCharacters("\n"));
// get the entry representation
Representation rep = app.getStorage().getEntry(feedBaseURI,feedPath,feed.getUUID(),entry.getUUID());
// avoid thread creation because reading an output representation requires a thread
StringWriter sw = new StringWriter();
rep.write(sw);
rep.release();
loader.generate(new StringReader(sw.toString()), new RemoveDocumentFilter(dest));
}
}
} catch (Exception ex) {
throw new XMLException("Exception while getting ancestors.",ex);
}
dest.send(constructor.createCharacters("\n"));
dest.send(constructor.createElementEnd(AtomResource.FEED_NAME));
dest.send(constructor.createDocumentEnd());
}
static void text(ItemConstructor constructor,ItemDestination dest,Name name,String text)
throws XMLException
{
dest.send(constructor.createElement(name));
dest.send(constructor.createCharacters(text));
dest.send(constructor.createElementEnd(name));
}
static void term(ItemConstructor constructor,ItemDestination dest,URI term,Object value)
throws XMLException
{
String [] parts = new String[2];
Term.split(term,parts);
try {
Element termE = constructor.createElement(AtomResource.CATEGORY_NAME);
if (!parts[0].equals("http://www.atomojo.org/O/keyword/")) {
termE.setAttributeValue("scheme",parts[0]);
}
termE.setAttributeValue("term",URLDecoder.decode(parts[1],"UTF-8"));
dest.send(termE);
if (value!=null && !(value instanceof Nil)) {
dest.send(constructor.createCharacters(value.toString()));
}
dest.send(constructor.createElementEnd(AtomResource.CATEGORY_NAME));
} catch (UnsupportedEncodingException ex) {
throw new XMLException("Cannot decode term "+parts[1],ex);
}
}
static void link(ItemConstructor constructor,ItemDestination dest,String rel,String href)
throws XMLException
{
Element linkE = constructor.createElement(AtomResource.LINK_NAME);
linkE.setAttributeValue("rel",rel);
linkE.setAttributeValue("href",href);
linkE.setAttributeValue("type","application/atom+xml");
dest.send(linkE);
dest.send(constructor.createElementEnd(AtomResource.LINK_NAME));
}
}