/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. 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.
*/
package org.apache.shindig.gadgets.templates;
import org.apache.shindig.auth.AnonymousSecurityToken;
import org.apache.shindig.common.cache.Cache;
import org.apache.shindig.common.cache.CacheProvider;
import org.apache.shindig.common.uri.Uri;
import org.apache.shindig.common.util.CharsetUtil;
import org.apache.shindig.common.util.HashUtil;
import org.apache.shindig.common.xml.XmlException;
import org.apache.shindig.common.xml.XmlUtil;
import org.apache.shindig.gadgets.GadgetContext;
import org.apache.shindig.gadgets.GadgetException;
import org.apache.shindig.gadgets.http.HttpRequest;
import org.apache.shindig.gadgets.http.HttpResponse;
import org.apache.shindig.gadgets.http.RequestPipeline;
import org.w3c.dom.Element;
import com.google.inject.Inject;
/**
* Factory for template libraries.
*/
public class TemplateLibraryFactory {
private static final String PARSED_XML_CACHE = "parsedXml";
private final RequestPipeline pipeline;
private final Cache<String, Element> parsedXmlCache;
@Inject
public TemplateLibraryFactory(RequestPipeline pipeline, CacheProvider cacheProvider) {
this.pipeline = pipeline;
// Support null cacheProvider only for testing
if (cacheProvider == null) {
this.parsedXmlCache = null;
} else {
this.parsedXmlCache = cacheProvider.createCache(PARSED_XML_CACHE);
}
}
public TemplateLibrary loadTemplateLibrary(GadgetContext context, Uri uri) throws GadgetException {
HttpRequest request = new HttpRequest(uri).setSecurityToken( new AnonymousSecurityToken( "", 0L, context.getUrl().toString()));
// 5 minute TTL.
request.setCacheTtl(300);
request.setIgnoreCache(context.getIgnoreCache());
HttpResponse response = pipeline.execute(request);
if (response.getHttpStatusCode() != HttpResponse.SC_OK) {
int retcode = response.getHttpStatusCode();
if (retcode == HttpResponse.SC_INTERNAL_SERVER_ERROR) {
// Convert external "internal error" to gateway error:
retcode = HttpResponse.SC_BAD_GATEWAY;
}
throw new GadgetException(GadgetException.Code.FAILED_TO_RETRIEVE_CONTENT,
"Unable to retrieve template library xml. HTTP error " +
response.getHttpStatusCode(), retcode);
}
String content = response.getResponseAsString();
try {
String key = null;
Element element = null;
if (!context.getIgnoreCache()) {
key = HashUtil.checksum(CharsetUtil.getUtf8Bytes(content));
element = parsedXmlCache.getElement(key);
}
if (element == null) {
element = XmlUtil.parse(content);
if (key != null) {
parsedXmlCache.addElement(key, element);
}
}
synchronized(element){
return new XmlTemplateLibrary(uri, element, content);
}
} catch (XmlException e) {
throw new GadgetException(GadgetException.Code.MALFORMED_XML_DOCUMENT, e,
HttpResponse.SC_BAD_REQUEST);
}
}
}