001    /*
002     * JBoss, Home of Professional Open Source.
003     * Copyright 2008, Red Hat Middleware LLC, and individual contributors
004     * as indicated by the @author tags. See the copyright.txt file in the
005     * distribution for a full listing of individual contributors. 
006     *
007     * This is free software; you can redistribute it and/or modify it
008     * under the terms of the GNU Lesser General Public License as
009     * published by the Free Software Foundation; either version 2.1 of
010     * the License, or (at your option) any later version.
011     *
012     * This software is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015     * Lesser General Public License for more details.
016     *
017     * You should have received a copy of the GNU Lesser General Public
018     * License along with this software; if not, write to the Free
019     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021     */
022    package org.jboss.dna.connector.federation.contribution;
023    
024    import net.jcip.annotations.Immutable;
025    import org.jboss.dna.graph.Location;
026    import org.jboss.dna.graph.properties.DateTime;
027    
028    /**
029     * A placeholder contribution needed because of a source's contribution below the specified children.
030     * 
031     * @author Randall Hauch
032     */
033    @Immutable
034    public class PlaceholderContribution extends MultiChildContribution {
035    
036        /**
037         * This is the first version of this class. See the documentation of MergePlan.serialVersionUID.
038         */
039        private static final long serialVersionUID = 1L;
040    
041        /**
042         * Create a contribution of children from the source with the supplied name.
043         * 
044         * @param sourceName the name of the source, which may not be null or blank
045         * @param locationInSource the location in the source for this contributed information; may not be null
046         * @param expirationTime the time (in UTC) after which this contribution should be considered expired, or null if there is no
047         *        expiration time
048         * @param children the children from the source; may not be null or empty
049         */
050        public PlaceholderContribution( String sourceName,
051                                        Location locationInSource,
052                                        DateTime expirationTime,
053                                        Iterable<Location> children ) {
054            super(sourceName, locationInSource, expirationTime, children);
055        }
056    
057        /**
058         * {@inheritDoc}
059         * 
060         * @see org.jboss.dna.connector.federation.contribution.Contribution#isPlaceholder()
061         */
062        @Override
063        public boolean isPlaceholder() {
064            return true;
065        }
066    }