+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ * VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.db.common.uri;\r
+\r
+import org.simantics.databoard.Bindings;\r
+import org.simantics.databoard.util.URIStringUtils;\r
+import org.simantics.db.ReadGraph;\r
+import org.simantics.db.Resource;\r
+import org.simantics.db.common.request.ResourceRead;\r
+import org.simantics.db.exception.AssumptionException;\r
+import org.simantics.db.exception.DatabaseException;\r
+import org.simantics.layer0.Layer0;\r
+\r
+/**\r
+ * Tries to retrieve URIs for specified resources. Throws\r
+ * {@link AssumptionException} if URI is undefined. This query follows the\r
+ * semantics of {@link ReadGraph#getURI(Resource)}.\r
+ * \r
+ * @author Antti Villberg\r
+ */\r
+public class ResourceToURI extends ResourceRead<String> {\r
+\r
+ public ResourceToURI(Resource resource) {\r
+ super(resource);\r
+ }\r
+\r
+ @Override\r
+ public String perform(ReadGraph graph) throws DatabaseException {\r
+ \r
+ if (resource.equals(graph.getRootLibrary())) return "http:/";\r
+ \r
+ Layer0 L0 = Layer0.getInstance(graph);\r
+ String name = graph.getPossibleRelatedValue(resource, L0.HasName, Bindings.STRING);\r
+ if (name == null) throw new AssumptionException("resource " + resource + " does not have a name");\r
+ \r
+ String escapedName = URIStringUtils.escape((String) name);\r
+ \r
+ Resource parent = graph.getPossibleObject(resource, L0.PartOf);\r
+ if(parent == null) throw new AssumptionException("resource " + resource + " does not have a parent");\r
+ \r
+ String parentURI = graph.syncRequest(new ResourceToURI(parent));\r
+ if(parentURI == null) throw new AssumptionException("parent resource " + parent + " has no URI");\r
+\r
+ return parentURI + "/" + escapedName;\r
+ \r
+ }\r
+\r
+}\r