bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/util/RelativeReference.java

   1 package org.simantics.db.layer0.util;\r
   2 \r
   3 import java.util.ArrayList;\r
   4 \r
   5 import org.simantics.databoard.util.URIStringUtils;\r
   6 import org.simantics.db.ReadGraph;\r
   7 import org.simantics.db.Resource;\r
   8 import org.simantics.db.common.uri.UnescapedChildMapOfResource;\r
   9 import org.simantics.db.exception.DatabaseException;\r
  10 import org.simantics.layer0.Layer0;\r
  11 \r
  12 public class RelativeReference {\r
  13     public final Resource base;\r
  14     public final String path;\r
  15     \r
  16     public RelativeReference(Resource base, String path) {\r
  17         this.base = base;\r
  18         this.path = path;\r
  19     }\r
  20     \r
  21     public Resource resolve(ReadGraph graph) throws DatabaseException {\r
  22         return resolve(graph, base, path);\r
  23     }\r
  24 \r
  25     public static Resource resolve(ReadGraph graph, \r
  26             Resource base, \r
  27             String path) throws DatabaseException {\r
  28         String[] splitPath = path.split("/");\r
  29         for(String name : splitPath) {            \r
  30             base = graph.syncRequest(new UnescapedChildMapOfResource(base)).get(\r
  31                     URIStringUtils.unescape(name)\r
  32                     );\r
  33             if(base == null)\r
  34                 return null;                    \r
  35         }\r
  36         return base;\r
  37     }\r
  38     \r
  39     public static RelativeReference createReference(ReadGraph graph, Resource baseType, Resource resource) throws DatabaseException {\r
  40         ArrayList<String> path = new ArrayList<String>();\r
  41         Layer0 L0 = Layer0.getInstance(graph);\r
  42         try {\r
  43             while(!graph.isInstanceOf(resource, baseType)) {\r
  44                 path.add((String)graph.getRelatedValue(resource, L0.HasName));\r
  45                 resource = graph.getSingleObject(resource, L0.PartOf);\r
  46             }\r
  47         } catch(DatabaseException e) {\r
  48             return null;\r
  49         }\r
  50         StringBuilder b = new StringBuilder();\r
  51         for(int i=path.size()-1;i>=0;--i) {\r
  52             b.append(URIStringUtils.escape(path.get(i)));\r
  53             if(i > 0)\r
  54                 b.append('/');\r
  55         }\r
  56         return new RelativeReference(resource, b.toString());\r
  57     }\r
  58 }\r