bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/adapter/ContextualRelatedValue.java

   1 /*******************************************************************************
   2  * Copyright (c) 2018 Association for Decentralized Information Management in
   3  * 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  *     Semantum Oy - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.db.layer0.adapter;
  13
  14 import org.simantics.db.ConverterComputationalValue;
  15 import org.simantics.db.ReadGraph;
  16 import org.simantics.db.Resource;
  17 import org.simantics.db.exception.DatabaseException;
  18 import org.simantics.db.exception.RuntimeDatabaseException;
  19 import org.simantics.db.layer0.variable.Variable;
  20 import org.simantics.scl.runtime.SCLContext;
  21 import org.simantics.scl.runtime.function.Function1;
  22 import org.simantics.scl.runtime.function.FunctionImpl3;
  23
  24 /**
  25  * @author Antti Villberg
  26  * @since 1.36.0
  27  */
  28 public abstract class ContextualRelatedValue implements ConverterComputationalValue {
  29
  30     @SuppressWarnings("unchecked")
  31     @Override
  32     public <T> T getValue(ReadGraph graph, Resource resource) throws DatabaseException {
  33         return (T) new FunctionImpl3<ReadGraph, Resource, Object, Object>() {
  34             @Override
  35             public Object apply(ReadGraph graph, Resource converter, Object context) {
  36                 SCLContext sclContext = SCLContext.getCurrent();
  37                 Object oldGraph = sclContext.get("graph");
  38                 try {
  39                     if (context instanceof Variable) {
  40                         Variable variable = (Variable)context;
  41                         try {
  42                             Function1<Object,Object> fn = getFunction(graph, variable.getParent(graph).getRepresents(graph), variable.getRepresents(graph), variable.getPredicateResource(graph));
  43                             sclContext.put("graph", graph);
  44                             return fn.apply(variable);
  45                         } catch (DatabaseException e) {
  46                             throw new RuntimeDatabaseException(e);
  47                         }
  48                     } if (context instanceof Resource) {
  49                         Resource resource = (Resource)context;
  50                         try {
  51                             // Here converter is the object and context is the subject
  52                             Function1<Object,Object> fn = getFunction(graph, resource, converter, null);
  53                             return fn.apply(resource);
  54                         } catch (DatabaseException e) {
  55                             throw new RuntimeDatabaseException(e);
  56                         }
  57                     } else {
  58                         throw new IllegalStateException("Unknown context " + context);
  59                     }
  60                 } finally {
  61                     sclContext.put("graph", oldGraph);
  62                 }
  63             }
  64         };
  65     }
  66
  67 }