'TriplePatternFragment' is a subinterface of 'LinkedDataFragment'

Author: Olaf Hartig

src/org/linkeddatafragments/datasource/TriplePatternFragment.java

@@ -1,18 +1,10 @@
 package org.linkeddatafragments.datasource;
 
-import com.hp.hpl.jena.rdf.model.Model;
-
 /**
  * A Triple Pattern Fragment.
  * @author Ruben Verborgh
  */
-public interface TriplePatternFragment {
-    /**
-     * Gets the data of this fragment (possibly only partial).
-     * @return the data as triples
-     */
-    public Model getTriples();
-
+public interface TriplePatternFragment extends LinkedDataFragment {
     /**
      * Gets the total number of triples in the fragment (can be an estimate).
      * @return the total number of triples

src/org/linkeddatafragments/datasource/TriplePatternFragmentImpl.java

@@ -1,40 +1,121 @@
 package org.linkeddatafragments.datasource;
 
+import org.linkeddatafragments.util.CommonResources;
+
+import com.hp.hpl.jena.datatypes.xsd.XSDDatatype;
+import com.hp.hpl.jena.rdf.model.Literal;
 import com.hp.hpl.jena.rdf.model.Model;
 import com.hp.hpl.jena.rdf.model.ModelFactory;
+import com.hp.hpl.jena.rdf.model.Resource;
+import com.hp.hpl.jena.rdf.model.StmtIterator;
 
 /**
- * Base implementation of a Basic Linked Data Fragment.
+ * Implementation of {@link TriplePatternFragment}.
+ *
  * @author Ruben Verborgh
+ * @author <a href="http://olafhartig.de">Olaf Hartig</a>
  */
-public class TriplePatternFragmentBase implements TriplePatternFragment {
+public class TriplePatternFragmentImpl extends LinkedDataFragmentBase
+                                       implements TriplePatternFragment
+{
     private final Model triples;
     private final long totalSize;
 
     /**
-     * Creates an empty Basic Linked Data Fragment.
+     * Creates an empty Triple Pattern Fragment.
+     */
+    public TriplePatternFragmentImpl( final String fragmentURL,
+                                      final String datasetURL ) {
+        this( null, 0L, fragmentURL, datasetURL, 1, true );
+    }
+
+    /**
+     * Creates an empty Triple Pattern Fragment page.
      */
-    public TriplePatternFragmentBase() {
-        this(null, 0);
+    public TriplePatternFragmentImpl( final String fragmentURL,
+                                      final String datasetURL,
+                                      final long pageNumber,
+                                      final boolean isLastPage ) {
+        this( null, 0L, fragmentURL, datasetURL, pageNumber, isLastPage );
     }
 
     /**
-     * Creates a new Basic Linked Data Fragment.
+     * Creates a new Triple Pattern Fragment.
      * @param triples the triples (possibly partial)
      * @param totalSize the total size
      */
-    public TriplePatternFragmentBase(Model triples, long totalSize) {
+    public TriplePatternFragmentImpl( Model triples,
+                                      long totalSize,
+                                      final String fragmentURL,
+                                      final String datasetURL,
+                                      final long pageNumber,
+                                      final boolean isLastPage ) {
+        super( fragmentURL, datasetURL, pageNumber, isLastPage );
         this.triples = triples == null ? ModelFactory.createDefaultModel() : triples;
         this.totalSize = totalSize < 0 ? 0 : totalSize;
     }
 
     @Override
-    public Model getTriples() {
-        return triples;
+    public StmtIterator getTriples() {
+        return triples.listStatements();
     }
 
     @Override
     public long getTotalSize() {
         return totalSize;
     }
+
+    @Override
+    public void addMetadata( final Model model )
+    {
+        super.addMetadata( model );
+
+        final Resource fragmentId = model.createResource( fragmentURL );
+
+        final Literal totalTyped = model.createTypedLiteral( totalSize,
+                                                      XSDDatatype.XSDinteger );
+        final Literal limitTyped = model.createTypedLiteral( getMaxPageSize(),
+                                                      XSDDatatype.XSDinteger );
+
+        fragmentId.addLiteral( CommonResources.VOID_TRIPLES, totalTyped );
+        fragmentId.addLiteral( CommonResources.HYDRA_TOTALITEMS, totalTyped );
+        fragmentId.addLiteral( CommonResources.HYDRA_ITEMSPERPAGE, limitTyped );
+    }
+
+    @Override
+    public void addControls( final Model model )
+    {
+        super.addControls( model );
+
+        final Resource datasetId = model.createResource( getDatasetURI() );
+
+        final Resource triplePattern = model.createResource();
+        final Resource subjectMapping = model.createResource();
+        final Resource predicateMapping = model.createResource();
+        final Resource objectMapping = model.createResource();
+
+        datasetId.addProperty( CommonResources.HYDRA_SEARCH, triplePattern );
+
+        triplePattern.addProperty( CommonResources.HYDRA_TEMPLATE, getTemplate() );
+        triplePattern.addProperty( CommonResources.HYDRA_MAPPING, subjectMapping );
+        triplePattern.addProperty( CommonResources.HYDRA_MAPPING, predicateMapping );
+        triplePattern.addProperty( CommonResources.HYDRA_MAPPING, objectMapping );
+
+        subjectMapping.addProperty( CommonResources.HYDRA_VARIABLE, TriplePatternFragmentRequest.PARAMETERNAME_SUBJ );
+        subjectMapping.addProperty( CommonResources.HYDRA_PROPERTY, CommonResources.RDF_SUBJECT );
+
+        predicateMapping.addProperty( CommonResources.HYDRA_VARIABLE, TriplePatternFragmentRequest.PARAMETERNAME_PRED );
+        predicateMapping.addProperty( CommonResources.HYDRA_PROPERTY, CommonResources.RDF_PREDICATE );
+        
+        objectMapping.addProperty( CommonResources.HYDRA_VARIABLE, TriplePatternFragmentRequest.PARAMETERNAME_OBJ );
+        objectMapping.addProperty( CommonResources.HYDRA_PROPERTY, CommonResources.RDF_OBJECT );
+    }
+
+    public String getTemplate() {
+        return datasetURL + "{?" +
+               TriplePatternFragmentRequest.PARAMETERNAME_SUBJ + "," +
+               TriplePatternFragmentRequest.PARAMETERNAME_PRED + "," +
+               TriplePatternFragmentRequest.PARAMETERNAME_OBJ + "}";
+    }
+
 }