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

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