bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/request/ChildrenByIdentifier.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.db.layer0.request;
  13
  14 import java.util.Collection;
  15 import java.util.HashMap;
  16 import java.util.Map;
  17
  18 import org.simantics.datatypes.literal.GUID;
  19 import org.simantics.db.ReadGraph;
  20 import org.simantics.db.Resource;
  21 import org.simantics.db.common.request.ResourceRead;
  22 import org.simantics.db.exception.DatabaseException;
  23 import org.simantics.layer0.Layer0;
  24
  25 /**
  26  * Get a map from GUIDs to the children of the given resource.
  27  */
  28 public final class ChildrenByIdentifier extends ResourceRead<Map<GUID, Resource>> {
  29         public ChildrenByIdentifier(Resource resource) {
  30                 super(resource);
  31         }
  32
  33         @Override
  34         public Map<GUID, Resource> perform(ReadGraph graph) throws DatabaseException {
  35                 Map<GUID, Resource> result = new HashMap<>();
  36                 Layer0 L0 = Layer0.getInstance(graph);
  37                 Collection<Resource> children = graph.getObjects(resource, L0.ConsistsOf);
  38                 for (Resource child : children) {
  39                         GUID guid = graph.getPossibleRelatedValue(child, L0.identifier, GUID.BINDING);
  40                         if (guid != null)
  41                                 result.put(guid, child);
  42                 }
  43
  44                 return result;
  45         }
  46 }