Thanks, I hope to get a chance to try this this week. I will let you know. I looks better than my kludge of using xslt to encode-for-uri.
Al >>> [EMAIL PROTECTED] 09/21/07 4:05 AM >>> Nico Verwer wrote: > I am looking at the same problem at the moment, and triied several > things (like the IncludeTransformer). My next attempt will be to build > a SPARQLTransformer. When it is ready, I'll let you know. I think the following code works. Please try it, and let me know if it works. The Java code follows: --------------------- /* * 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.cocoon.transformation; import java.io.IOException; import java.util.Map; import org.apache.avalon.framework.parameters.Parameters; import org.apache.cocoon.ProcessingException; import org.apache.cocoon.components.source.SourceUtil; import org.apache.cocoon.environment.SourceResolver; import org.apache.excalibur.source.Source; import org.apache.excalibur.source.SourceParameters; import org.xml.sax.Attributes; import org.xml.sax.SAXException; /** * * @cocoon.sitemap.component.documentation * This transformer triggers for the element <code>query</code> in the namespace "http://apache.org/cocoon/sparql/1.0";. * These elements must not be nested. * The <code>src</code> attribute contains the url which points to a SPARQL endpoint. * The optional <code>method</code> attribute contains the HTTP method for the request (default is GET). * Attributes in the "http://apache.org/cocoon/sparql/1.0"; namespace are used as request parameters (using the local name). * This allows for parameters such as 'format' or 'maxrows'. * The text of the content of the <code>query</code> element is passed as the value of the 'query' parameter. * * The XML input to this transformer would look like: * <pre> * <sparql:query xmlns:sparql="http://apache.org/cocoon/sparql/1.0"; * method="POST" src="http://dbpedia.org/sparql"; * sparql:maxrows="25" sparql:format="XML" * > * <![CDATA[ * PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> * SELECT * * FROM <http://dbpedia.org> * WHERE { * ?person rdf:type <http://dbpedia.org/class/yago/Person100007846> . * } * ]]> * </sparql:query> * </pre> * * @author Nico Verwer * */ public class SparqlTransformer extends AbstractSAXTransformer { public static final String SPARQL_NAMESPACE_URI = "http://apache.org/cocoon/sparql/1.0";; public static final String QUERY_ELEMENT = "query"; public static final String METHOD_ATTR = "method"; public static final String SRC_ATTR = "src"; public static final String QUERY_PARAM = "query"; private boolean inQuery; private String src; private String method; private SourceParameters requestParameters; public SparqlTransformer() { this.defaultNamespaceURI = SPARQL_NAMESPACE_URI; } public void setup(SourceResolver resolver, Map objectModel, String src, Parameters params) throws ProcessingException, SAXException, IOException { super.setup(resolver, objectModel, src, params); inQuery = false; } public void startTransformingElement(String uri, String name, String raw, Attributes attr) throws ProcessingException, IOException, SAXException { if (name.equals(QUERY_ELEMENT)) { if (inQuery) { throw new ProcessingException("Nested SPARQL queries are not allowed."); } inQuery = true; src = attr.getValue(SRC_ATTR); method = attr.getValue(METHOD_ATTR); method = (method == null ? "GET" : method.toUpperCase()); requestParameters = new SourceParameters(); for (int i = 0; i < attr.getLength(); ++i) { if (attr.getURI(i).equals(SPARQL_NAMESPACE_URI)) { requestParameters.setParameter(attr.getLocalName(i), attr.getValue(i)); } } startTextRecording(); } } public void endTransformingElement(String uri, String name, String raw) throws ProcessingException, IOException, SAXException { if (name.equals(QUERY_ELEMENT)) { inQuery = false; String query = endTextRecording(); requestParameters.setParameter(QUERY_PARAM, query); Parameters typeParameters = new Parameters(); typeParameters.setParameter("method", method); Source source = SourceUtil.getSource(src, typeParameters, requestParameters, resolver); SourceUtil.toSAX(source, this.xmlConsumer); } } } --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] -- This message has been verified by LastSpam eMail security service Ce courriel a été vérifié par le service de sécurité pour courriels LastSpam http://www.lastspam.com --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
