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

   1 package org.simantics.db.layer0.request;\r
   2 \r
   3 import java.util.Collection;\r
   4 \r
   5 import org.simantics.db.ReadGraph;\r
   6 import org.simantics.db.Resource;\r
   7 import org.simantics.db.common.request.ResourceRead;\r
   8 import org.simantics.db.common.utils.NameUtils;\r
   9 import org.simantics.db.exception.DatabaseException;\r
  10 import org.simantics.db.exception.NoSingleResultException;\r
  11 \r
  12 /**\r
  13  * Returns the active model or null if no single active model is available.\r
  14  */\r
  15 public class SingleActiveModel extends ResourceRead<Resource> {\r
  16 \r
  17     public SingleActiveModel(Resource project) {\r
  18         super(project);\r
  19     }\r
  20 \r
  21     @Override\r
  22     public Resource perform(ReadGraph graph) throws DatabaseException {\r
  23         Collection<Resource> actives = graph.syncRequest(new ActiveModels(resource));\r
  24         if (actives.size() == 1)\r
  25             return actives.iterator().next();\r
  26 \r
  27         if (actives.size() == 0) \r
  28                 throw new NoSingleResultException("There are no active models."); \r
  29 \r
  30         throw new NoSingleResultException("There are many active models: " + NameUtils.getSafeName(graph, actives)); \r
  31         \r
  32     }\r
  33 \r
  34 }\r