/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org. All rights reserved.
* This code is licensed under the GPL 2.0 license, availible at the root
* application directory.
*/
package org.geoserver.wms.georss;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.logging.Level;
import org.geoserver.wms.WMS;
import org.geoserver.wms.WMSMapContext;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.feature.FeatureIterator;
import org.geotools.xml.transform.Translator;
import org.opengis.feature.simple.SimpleFeature;
import org.xml.sax.ContentHandler;
import org.xml.sax.helpers.AttributesImpl;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;
/**
* Encodes an RSS feed tagged with geo information.
*
* @author Justin Deoliveira, The Open Planning Project, jdeolive@openplans.org
*
*/
public class RSSGeoRSSTransformer extends GeoRSSTransformerBase {
private WMS wms;
public RSSGeoRSSTransformer(WMS wms){
this.wms = wms;
}
public Translator createTranslator(ContentHandler handler) {
return new RSSGeoRSSTranslator(wms, handler);
}
class RSSGeoRSSTranslator extends GeoRSSTranslatorSupport {
private WMS wms;
public RSSGeoRSSTranslator(WMS wms, ContentHandler contentHandler) {
super(contentHandler, null, null);
this.wms = wms;
nsSupport.declarePrefix("georss", "http://www.georss.org/georss");
nsSupport.declarePrefix("atom", "http://www.w3.org/2005/Atom");
}
public void encode(Object o) throws IllegalArgumentException {
WMSMapContext map = (WMSMapContext) o;
AttributesImpl atts = new AttributesImpl();
atts.addAttribute(null, "version", "version", null, "2.0");
start("rss", atts);
start("channel");
element( "title", AtomUtils.getFeedTitle(map) );
element("description", "Feed auto-generated by GeoServer");
start( "link" );
cdata(AtomUtils.getFeedURL(map));
end( "link" );
atts = new AttributesImpl();
atts.addAttribute(null, "href", "href", null, AtomUtils.getFeedURL(map));
atts.addAttribute(null, "rel", "rel", null, "self");
element("atom:link", null, atts);
//items
try {
encodeItems(map);
} catch (IOException e) {
throw new RuntimeException(e);
}
end("channel");
end("rss");
}
void encodeItems(WMSMapContext map) throws IOException {
List featureCollections = loadFeatureCollections(map);
for (Iterator f = featureCollections.iterator(); f.hasNext(); ) {
SimpleFeatureCollection features = (SimpleFeatureCollection) f.next();
FeatureIterator <SimpleFeature> iterator = null;
try {
iterator = features.features();
while (iterator.hasNext()) {
SimpleFeature feature = iterator.next();
try {
encodeItem(feature, map);
}
catch( Exception e ) {
LOGGER.warning("Encoding failed for feature: " + feature.getID());
LOGGER.log(Level.FINE, "", e );
}
}
} finally {
if (iterator != null) {
features.close(iterator);
}
}
}
}
void encodeItem(SimpleFeature feature, WMSMapContext map)
throws IOException {
start("item");
String title = feature.getID();
String link = null;
String description = "[Error while loading description]";
try {
title = AtomUtils.getFeatureTitle(feature);
link = AtomUtils.getEntryURL(wms, feature, map);
description = AtomUtils.getFeatureDescription(feature);
} catch( Exception e ) {
String msg = "Error occured executing title template for: " + feature.getID();
LOGGER.log( Level.WARNING, msg, e );
}
element("title", title);
//create the link as getFeature request with fid filter
start("link");
cdata(link);
end("link");
start("guid");
cdata(link);
end("guid");
start("description");
cdata(AtomUtils.getFeatureDescription(feature));
end("description");
GeometryCollection col = feature.getDefaultGeometry() instanceof GeometryCollection
? (GeometryCollection) feature.getDefaultGeometry()
: null;
if (geometryEncoding == GeometryEncoding.LATLONG
|| (col == null && feature.getDefaultGeometry() != null)) {
geometryEncoding.encode((Geometry)feature.getDefaultGeometry(), this);
end("item");
} else {
geometryEncoding.encode(col.getGeometryN(0), this);
end("item");
for (int i = 1; i < col.getNumGeometries(); i++){
encodeRelatedGeometryItem(col.getGeometryN(i), title, link, i);
}
}
}
void encodeRelatedGeometryItem(Geometry g, String title, String link, int count){
start("item");
element("title", "Continuation of " + title);
element("link", link);
element("guid", link + "#" + count);
element("description", "Continuation of " + title);
geometryEncoding.encode(g, this);
end("item");
}
}
}