- public void perform(AsyncReadGraph graph, final AsyncProcedure<Resource> procedure) {
-
- final Layer0 l0 = graph.getService(Layer0.class);
-
- graph.forIsInstanceOf(resource, resource2, new AsyncProcedure<Boolean>() {
-
- @Override
- public void execute(AsyncReadGraph graph, Boolean isInstance) {
- if(isInstance) {
- procedure.execute(graph, resource);
- } else {
-
- graph.forPossibleObject(resource, l0.PartOf, new AsyncProcedure<Resource>() {
-
- @Override
- public void execute(AsyncReadGraph graph, final Resource parent) {
-
- if(parent == null) {
- procedure.execute(graph, null);
- } else {
- graph.asyncRequest(new PossibleTypedParent(parent, resource2), procedure);
- }
-
- }
-
- @Override
- public void exception(AsyncReadGraph graph, Throwable throwable) {
- procedure.exception(graph, throwable);
- }
-
- });
-
- }
- }
-
- @Override
- public void exception(AsyncReadGraph graph, Throwable throwable) {
- procedure.exception(graph, throwable);
+ public Resource perform(ReadGraph graph) throws DatabaseException {
+ if (graph.isInstanceOf(resource, resource2)) {
+ return resource;
+ } else {
+ Layer0 L0 = Layer0.getInstance(graph);
+ Resource possibleParent = graph.getPossibleObject(resource, L0.PartOf);
+ if (possibleParent != null) {
+ return graph.syncRequest(new PossibleTypedParent(possibleParent, resource2));
+ } else {
+ return null;