001/*
002 * Copyright 2015 DuraSpace, Inc.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.fcrepo.kernel.modeshape.rdf.impl;
017
018import com.hp.hpl.jena.graph.Triple;
019import com.hp.hpl.jena.rdf.model.Resource;
020import org.fcrepo.kernel.api.models.NonRdfSourceDescription;
021import org.fcrepo.kernel.api.models.FedoraResource;
022import org.fcrepo.kernel.api.identifiers.IdentifierConverter;
023import org.slf4j.Logger;
024
025import javax.jcr.RepositoryException;
026
027import static java.util.stream.Stream.of;
028import static com.hp.hpl.jena.datatypes.xsd.XSDDatatype.XSDlong;
029import static com.hp.hpl.jena.graph.Triple.create;
030import static com.hp.hpl.jena.rdf.model.ResourceFactory.createTypedLiteral;
031import static org.fcrepo.kernel.api.RdfLexicon.CONTAINS;
032import static org.fcrepo.kernel.api.RdfLexicon.HAS_CHILD_COUNT;
033import static org.slf4j.LoggerFactory.getLogger;
034
035/**
036 * @author cabeer
037 * @author ajs6f
038 * @since 9/16/14
039 */
040public class ChildrenRdfContext extends NodeRdfContext {
041
042    private static final Logger LOGGER = getLogger(ChildrenRdfContext.class);
043
044    /**
045     * Default constructor.
046     *
047     * @param resource the resource
048     * @param idTranslator the idTranslator
049     * @throws javax.jcr.RepositoryException if repository exception occurred
050     */
051    public ChildrenRdfContext(final FedoraResource resource,
052                              final IdentifierConverter<Resource, FedoraResource> idTranslator)
053            throws RepositoryException {
054        super(resource, idTranslator);
055
056        if (resource.getNode().hasNodes()) {
057            LOGGER.trace("Found children of this resource: {}", resource.getPath());
058
059            // Count the number of children
060            concat(of(createNumChildrenTriple(resource().getChildren().count())));
061            concat(resource().getChildren().peek(child -> LOGGER.trace("Creating triple for child node: {}", child))
062                    .map(child -> create(subject(), CONTAINS.asNode(), child instanceof NonRdfSourceDescription ?
063                            uriFor(((NonRdfSourceDescription) child).getDescribedResource()) : uriFor(child))));
064        } else {
065            concat(of(createNumChildrenTriple(0)));
066        }
067
068    }
069
070    private Triple createNumChildrenTriple(final long numChildren) {
071        return create(subject(),
072                HAS_CHILD_COUNT.asNode(),
073                createTypedLiteral(Long.toString(numChildren), XSDlong).asNode());
074    }
075
076}