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     private final FunctionImpl3<ReadGraph, Resource, Object, Object> function = new FunctionImpl3<ReadGraph, Resource, Object, Object>() {
  31         @Override
  32         public Object apply(ReadGraph graph, Resource converter, Object context) {
  33             SCLContext sclContext = SCLContext.getCurrent();
  34             Object oldGraph = sclContext.get("graph");
  35             try {
  36                 if (context instanceof Variable) {
  37                     Variable variable = (Variable)context;
  38                     try {
  39                         Function1<Object,Object> fn = getFunction(graph, variable.getParent(graph).getRepresents(graph), variable.getRepresents(graph), variable.getPredicateResource(graph));
  40                         sclContext.put("graph", graph);
  41                         return fn.apply(variable);
  42                     } catch (DatabaseException e) {
  43                         throw new RuntimeDatabaseException(e);
  44                     }
  45                 } if (context instanceof Resource) {
  46                     Resource resource = (Resource)context;
  47                     try {
  48                         // Here converter is the object and context is the subject
  49                         Function1<Object,Object> fn = getFunction(graph, resource, converter, null);
  50                         return fn.apply(resource);
  51                     } catch (DatabaseException e) {
  52                         throw new RuntimeDatabaseException(e);
  53                     }
  54                 } else {
  55                     throw new IllegalStateException("Unknown context " + context);
  56                 }
  57             } finally {
  58                 sclContext.put("graph", oldGraph);
  59             }
  60         }
  61     };
  62
  63     @SuppressWarnings("unchecked")
  64     @Override
  65     public <T> T getValue(ReadGraph graph, Resource resource) throws DatabaseException {
  66         return (T) function;
  67     }
  68
  69 }