added a dynamic list of all resources when index is requested (and In…

…dexResource is missing on the configuration)
wikier · Apr 3, 2012 · 5070a4d · 5070a4d
1 parent 1591c67
commit 5070a4d
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Showing 4 changed files with 85 additions and 16 deletions.
diff --git a/src/de/fuberlin/wiwiss/pubby/Configuration.java b/src/de/fuberlin/wiwiss/pubby/Configuration.java
@@ -26,6 +26,8 @@
  * @version $Id$
  */
 public class Configuration {
+
+	public static final String INDEX = "index"; 
 	private final Model model;
 	private final Resource config;
 	private final PrefixMapping prefixes;
@@ -46,7 +48,7 @@ public Configuration(Model configurationModel) {
 		datasets = new ArrayList();
 		it = model.listStatements(config, CONF.dataset, (RDFNode) null);
 		while (it.hasNext()) {
-			datasets.add(new Dataset(it.nextStatement().getResource()));
+			datasets.add(new Dataset(it.nextStatement().getResource(), this.getWebApplicationBaseURI()));
 		}
 		labelProperties = new ArrayList();
 		it = model.listStatements(config, CONF.labelProperty, (RDFNode) null);
@@ -158,4 +160,16 @@ public String getProjectName() {
 	public String getWebApplicationBaseURI() {
 		return config.getProperty(CONF.webBase).getResource().getURI();
 	}
+
+	public String buildIndexResource() {
+		String webApplicationBaseURI = this.getWebApplicationBaseURI();
+		Statement dataset = this.config.getProperty(CONF.dataset);
+		String webResourcePrefix = dataset.getProperty(CONF.webResourcePrefix).getString();
+		return buildIndexResource(webApplicationBaseURI, webResourcePrefix);
+	}
+
+	public static String buildIndexResource(String webApplicationBaseURI, String webResourcePrefix) {
+		return  webApplicationBaseURI + webResourcePrefix + INDEX;
+	}
+
 }
diff --git a/src/de/fuberlin/wiwiss/pubby/Dataset.java b/src/de/fuberlin/wiwiss/pubby/Dataset.java
@@ -42,9 +42,10 @@ public class Dataset {
 	private final static String metadataPlaceholderURIPrefix = "about:metadata:";
 	private Calendar currentTime;
 	private Resource currentDocRepr;
+	private String webBase;
 
-	public Dataset(Resource config) {
-		model = config.getModel();
+	public Dataset(Resource config, String webBase) {
+		this.model = config.getModel();
 		this.config = config;
 		if (config.hasProperty(CONF.datasetURIPattern)) {
 			datasetURIPattern = Pattern.compile(
@@ -73,10 +74,10 @@ public Dataset(Resource config) {
 		}
 		if (config.hasProperty(CONF.sparqlEndpoint)) {
 			String endpointURL = config.getProperty(CONF.sparqlEndpoint).getResource().getURI();
-			String defaultGraph = config.hasProperty(CONF.sparqlDefaultGraph)
-					? config.getProperty(CONF.sparqlDefaultGraph).getResource().getURI()
-					: null;
-			dataSource = new RemoteSPARQLDataSource(endpointURL, defaultGraph);
+			String graphName = config.hasProperty(CONF.sparqlDefaultGraph)
+								? config.getProperty(CONF.sparqlDefaultGraph).getResource().getURI()
+								: null;
+			dataSource = new RemoteSPARQLDataSource(endpointURL, graphName, webBase, this.getWebResourcePrefix());
 		} else {
 			Model data = ModelFactory.createDefaultModel();
 			StmtIterator it = config.listProperties(CONF.loadRDF);
@@ -356,4 +357,5 @@ private String escapeURIDelimiters(String uri) {
 	private String unescapeURIDelimiters(String uri) {
 		return uri.replaceAll("%23", "#").replaceAll("%3F", "?");
 	}
+
 }
diff --git a/src/de/fuberlin/wiwiss/pubby/RemoteSPARQLDataSource.java b/src/de/fuberlin/wiwiss/pubby/RemoteSPARQLDataSource.java
@@ -6,23 +6,36 @@
 
 import com.hp.hpl.jena.rdf.model.Model;
 import com.hp.hpl.jena.rdf.model.Property;
+import com.hp.hpl.jena.rdf.model.ResIterator;
+import com.hp.hpl.jena.rdf.model.Resource;
+import com.hp.hpl.jena.rdf.model.Statement;
 import com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP;
 
+import de.fuberlin.wiwiss.pubby.vocab.CONF;
+import de.fuberlin.wiwiss.pubby.vocab.RDF;
+
 /**
  * A data source backed by a SPARQL endpoint accessed through
  * the SPARQL protocol.
  * 
  * @author Richard Cyganiak (richard@cyganiak.de)
+ * @author Sergio Fernández (sergio.fernandez@fundacionctic.org)
  * @version $Id$
  */
 public class RemoteSPARQLDataSource implements DataSource {
+
+	private Resource config;
 	private String endpointURL;
 	private String defaultGraphName;
+	private String webResourcePrefix;
+	private String webBase;
 	private String previousDescribeQuery;
 
-	public RemoteSPARQLDataSource(String endpointURL, String defaultGraphName) {
+	public RemoteSPARQLDataSource(String endpointURL, String graphName, String webBase, String webResourcePrefix) {
 		this.endpointURL = endpointURL;
-		this.defaultGraphName = defaultGraphName;
+		this.defaultGraphName = graphName;
+		this.webBase = webBase;
+		this.webResourcePrefix = webResourcePrefix;
 	}
 
 	public String getEndpointURL() {
@@ -40,16 +53,25 @@ public String getResourceDescriptionURL(String resourceURI) {
 				result.append("&");
 			}
 			result.append("query=");
-			result.append(URLEncoder.encode("DESCRIBE <" + resourceURI + ">", "utf-8"));
+			result.append(URLEncoder.encode(buildDescribeQuery(resourceURI), "utf-8"));
 			return result.toString();
 		} catch (UnsupportedEncodingException ex) {
 			// can't happen, utf-8 is always supported
 			throw new RuntimeException(ex);
 		}
 	}
+
+	private String buildDescribeQuery(String resourceURI) {
+		String index = Configuration.buildIndexResource(this.webBase, this.webResourcePrefix);
+		if (index.equals(resourceURI)) {
+			return "CONSTRUCT { ?s <" + RDF.type.getURI() + "> ?o } WHERE { ?s <" + RDF.type.getURI() + "> ?o }";
+		} else {
+			return "DESCRIBE <" + resourceURI + ">";
+		}
+	}
 
 	public Model getResourceDescription(String resourceURI) {
-		return execDescribeQuery("DESCRIBE <" + resourceURI + ">");
+		return execDescribeQuery(buildDescribeQuery(resourceURI));
 	}
 
 	public Model getAnonymousPropertyValues(String resourceURI, Property property, boolean isInverse) {
@@ -71,6 +93,27 @@ private Model execDescribeQuery(String query) {
 		if (defaultGraphName != null) {
 			endpoint.setDefaultGraphURIs(Collections.singletonList(defaultGraphName));
 		}
-		return endpoint.execDescribe();
+
+		//FIXME: more elegant way to discriminate query execution 
+		//		 (lateral effect from introducing CONSTRUCT query for listing all resources on index)
+		if (query.startsWith("CONSTRUCT")) {
+			Model model = endpoint.execConstruct();
+			Property containerOf = model.createProperty("http://rdfs.org/sioc/ns#container_of");
+			ResIterator iter = model.listSubjects();
+			Resource index = model.createResource(Configuration.buildIndexResource(this.webBase, this.webResourcePrefix));
+			while (iter.hasNext()) {
+				Resource o = iter.next();
+				if (!index.equals(o)) {
+					Statement statement = model.createStatement(index, containerOf, o);
+					model.add(statement);
+				}
+			}
+			model.addLiteral(index, 
+							 model.createProperty("http://www.w3.org/2000/01/rdf-schema#label"), 
+							 model.createLiteral("Synthetic container for listing by default all resources on pubby"));
+			return model;
+		} else {
+			return endpoint.execDescribe();
+		}
 	}
 }
diff --git a/src/de/fuberlin/wiwiss/pubby/servlets/RootServlet.java b/src/de/fuberlin/wiwiss/pubby/servlets/RootServlet.java
@@ -12,10 +12,13 @@
  * A catch-all servlet managing the URI space of the web application.
  * 
  * @author Richard Cyganiak (richard@cyganiak.de)
+ * @author Sergio Fernández (sergio.fernandez@fundacionctic.org)
  * @version $Id$
  */
 public class RootServlet extends BaseServlet {
 
+	private static final long serialVersionUID = -4812044304620174504L;
+
 	protected boolean doGet(String relativeURI,
 			HttpServletRequest request, HttpServletResponse response,
 			Configuration config)
@@ -27,10 +30,17 @@ protected boolean doGet(String relativeURI,
 			return true;
 		}
 
-		// If index resource is defined, redirect requests for the index page to it
-		if ("".equals(relativeURI) && config.getIndexResource() != null) {
-			response.sendRedirect(config.getIndexResource().getWebURI());
-			return true;
+		if ("".equals(relativeURI)) {
+			// If index resource is defined
+			// redirect requests for the index page to it
+			// if not, list all resources
+			if (config.getIndexResource() != null) {
+				response.sendRedirect(config.getIndexResource().getWebURI());
+				return true;
+			} else {
+				response.sendRedirect(config.buildIndexResource());
+				return true;
+			}
 		}
 
 		// Assume it's a resource URI -- will produce 404 if not