/*
* 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 org.rometools.feed.module.opensearch.impl;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import org.jdom2.Attribute;
import org.jdom2.Element;
import org.jdom2.Namespace;
import org.jdom2.Parent;
import com.sun.syndication.feed.atom.Link;
import com.sun.syndication.feed.module.Module;
import org.rometools.feed.module.opensearch.OpenSearchModule;
import org.rometools.feed.module.opensearch.entity.OSQuery;
import com.sun.syndication.io.ModuleParser;
/**
* @author Michael W. Nassif (enrouteinc@gmail.com)
* OpenSearch implementation of the ModuleParser class
*/
public class OpenSearchModuleParser implements ModuleParser{
private static final Namespace OS_NS = Namespace.getNamespace("opensearch", OpenSearchModule.URI);
public String getNamespaceUri() {
return OpenSearchModule.URI;
}
public Module parse(Element dcRoot) {
URL baseURI = findBaseURI(dcRoot);
boolean foundSomething = false;
OpenSearchModule osm = new OpenSearchModuleImpl();
Element e = dcRoot.getChild("totalResults", OS_NS);
if (e != null) {
foundSomething = true;
try{
osm.setTotalResults(Integer.parseInt(e.getText()));
} catch(NumberFormatException ex){
// Ignore setting the field and post a warning
System.err.println("Warning: The element totalResults must be an integer value: " + ex.getMessage());
}
}
e = dcRoot.getChild("itemsPerPage", OS_NS);
try{
osm.setItemsPerPage(Integer.parseInt(e.getText()));
} catch(NumberFormatException ex){
// Ignore setting the field and post a warning
System.err.println("Warning: The element itemsPerPage must be an integer value: " + ex.getMessage());
}
e = dcRoot.getChild("startIndex", OS_NS);
try{
osm.setStartIndex(Integer.parseInt(e.getText()));
} catch(NumberFormatException ex){
// Ignore setting the field and post a warning
System.err.println("Warning: The element startIndex must be an integer value: " + ex.getMessage());
}
List queries = dcRoot.getChildren("Query", OS_NS);
if(queries != null && queries.size() > 0){
// Create the OSQuery list
List osqList = new LinkedList();
for (Iterator iter = queries.iterator(); iter.hasNext();) {
e = (Element) iter.next();
osqList.add(parseQuery(e));
}
osm.setQueries(osqList);
}
e = dcRoot.getChild("link", OS_NS);
if(e != null){
osm.setLink(parseLink(e, baseURI));
}
return (foundSomething) ? osm : null;
}
private static OSQuery parseQuery(Element e){
OSQuery query = new OSQuery();
String att = e.getAttributeValue("role");
query.setRole(att);
att = e.getAttributeValue("osd");
query.setOsd(att);
att = e.getAttributeValue("searchTerms");
query.setSearchTerms(att);
att = e.getAttributeValue("title");
query.setTitle(att);
try{
// someones mistake should not cause the parser to fail, since these are only optional attributes
att = e.getAttributeValue("totalResults");
if(att != null){
query.setTotalResults(Integer.parseInt(att));
}
att = e.getAttributeValue("startPage");
if(att != null){
query.setStartPage(Integer.parseInt(att));
}
} catch(NumberFormatException ex){
System.err.println("Warning: Exception caught while trying to parse a non-numeric Query attribute " + ex.getMessage());
}
return query;
}
private static Link parseLink(Element e, URL baseURI) {
Link link = new Link();
String att = e.getAttributeValue("rel");//getAtomNamespace()); DONT KNOW WHY DOESN'T WORK
if (att!=null) {
link.setRel(att);
}
att = e.getAttributeValue("type");//getAtomNamespace()); DONT KNOW WHY DOESN'T WORK
if (att!=null) {
link.setType(att);
}
att = e.getAttributeValue("href");//getAtomNamespace()); DONT KNOW WHY DOESN'T WORK
if (att!=null) {
if (isRelativeURI(att)) { //
link.setHref(resolveURI(baseURI, e, ""));
} else {
link.setHref(att);
}
}
att = e.getAttributeValue("hreflang");//getAtomNamespace()); DONT KNOW WHY DOESN'T WORK
if (att!=null) {
link.setHreflang(att);
}
att = e.getAttributeValue("length");//getAtomNamespace()); DONT KNOW WHY DOESN'T WORK
return link;
}
private static boolean isRelativeURI(String uri) {
if ( uri.startsWith("http://")
|| uri.startsWith("https://")
|| uri.startsWith("/")) {
return false;
}
return true;
}
/** Use xml:base attributes at feed and entry level to resolve relative links */
private static String resolveURI(URL baseURI, Parent parent, String url) {
url = (url.equals(".") || url.equals("./")) ? "" : url;
if (isRelativeURI(url) && parent != null && parent instanceof Element) {
Attribute baseAtt = ((Element)parent).getAttribute("base", Namespace.XML_NAMESPACE);
String xmlBase = (baseAtt == null) ? "" : baseAtt.getValue();
if (!isRelativeURI(xmlBase) && !xmlBase.endsWith("/")) {
xmlBase = xmlBase.substring(0, xmlBase.lastIndexOf("/")+1);
}
return resolveURI(baseURI, parent.getParent(), xmlBase + url);
} else if (isRelativeURI(url) && parent == null) {
return baseURI + url;
} else if (baseURI != null && url.startsWith("/")) {
String hostURI = baseURI.getProtocol() + "://" + baseURI.getHost();
if (baseURI.getPort() != baseURI.getDefaultPort()) {
hostURI = hostURI + ":" + baseURI.getPort();
}
return hostURI + url;
}
return url;
}
/** Use feed links and/or xml:base attribute to determine baseURI of feed */
private static URL findBaseURI(Element root) {
URL baseURI = null;
List linksList = root.getChildren("link", OS_NS);
if (linksList != null) {
for (Iterator links = linksList.iterator(); links.hasNext(); ) {
Element link = (Element)links.next();
if (!root.equals(link.getParent())) break;
String href = link.getAttribute("href").getValue();
if ( link.getAttribute("rel", OS_NS) == null
|| link.getAttribute("rel", OS_NS).getValue().equals("alternate")) {
href = resolveURI(null, link, href);
try {
baseURI = new URL(href);
break;
} catch (MalformedURLException e) {
System.err.println("Base URI is malformed: " + href);
}
}
}
}
return baseURI;
}
}