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1   /*
2    * Copyright 2015 Data Archiving and Networked Services (an institute of
3    * Koninklijke Nederlandse Akademie van Wetenschappen), King's College London,
4    * Georg-August-Universitaet Goettingen Stiftung Oeffentlichen Rechts
5    *
6    * Licensed under the EUPL, Version 1.1 or – as soon they will be approved by
7    * the European Commission - subsequent versions of the EUPL (the "Licence");
8    * You may not use this work except in compliance with the Licence.
9    * You may obtain a copy of the Licence at:
10   *
11   * https://joinup.ec.europa.eu/software/page/eupl
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the Licence is distributed on an "AS IS" basis,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the Licence for the specific language governing
17   * permissions and limitations under the Licence.
18   */
19  
20  package eu.ehri.project.models.base;
21  
22  import com.tinkerpop.blueprints.Direction;
23  import com.tinkerpop.blueprints.Vertex;
24  import com.tinkerpop.frames.Adjacency;
25  import com.tinkerpop.frames.modules.javahandler.JavaHandler;
26  import com.tinkerpop.frames.modules.javahandler.JavaHandlerContext;
27  import eu.ehri.project.definitions.Ontology;
28  import eu.ehri.project.models.events.Version;
29  import eu.ehri.project.models.utils.JavaHandlerUtils;
30  
31  /**
32   * An entity that may have prior versions.
33   */
34  public interface Versioned extends Accessible {
35      /**
36       * Get the most recent version for this item, if one exists.
37       *
38       * @return a version frame, or null if there is no prior version
39       */
40      @Adjacency(label = Ontology.ENTITY_HAS_PRIOR_VERSION, direction = Direction.OUT)
41      Version getPriorVersion();
42  
43      /**
44       * Loops through the chain of prior versions until the oldest existing version.
45       *
46       * @return an iterable of prior item versions
47       */
48      @JavaHandler
49      Iterable<Version> getAllPriorVersions();
50  
51      abstract class Impl implements JavaHandlerContext<Vertex>, Versioned {
52  
53          public Iterable<Version> getAllPriorVersions() {
54              return frameVertices(gremlin().as("n").out(Ontology.ENTITY_HAS_PRIOR_VERSION)
55                      .loop("n", JavaHandlerUtils.noopLoopFunc, JavaHandlerUtils.noopLoopFunc));
56          }
57      }
58  }