From c433e87787fb162d3f5d966678aaedf491266080 Mon Sep 17 00:00:00 2001
From: Reino Ruusu <reino.ruusu@semantum.fi>
Date: Wed, 5 Feb 2020 15:47:13 +0200
Subject: [PATCH] Non-constant external value configuration via procedural UCs.

gitlab #461

Change-Id: I764644ea60a421e6c807486c925ccd9e33aa6928
---
 .../StandardProceduralChildVariable.java      |  9 +++
 .../StandardProdeduralPropertyVariable.java   | 71 +++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProdeduralPropertyVariable.java

diff --git a/bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProceduralChildVariable.java b/bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProceduralChildVariable.java
index e96fd050a..e7ba5ab78 100644
--- a/bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProceduralChildVariable.java
+++ b/bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProceduralChildVariable.java
@@ -7,6 +7,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 import org.simantics.databoard.Bindings;
@@ -115,6 +116,14 @@ public class StandardProceduralChildVariable extends AbstractChildVariable {
 		    } else if (p.value instanceof Expression) {
 		    	Expression expression = (Expression)p.value;
 			    this.properties.put(pn, new StructuralProceduralExpressionPropertyVariable(graph, this, p.relation, expression.text) );
+		    } else if (this.properties.containsKey(pn)) {
+		    	// The property overrides the value of an asserted property variable
+		    	StandardAssertedGraphPropertyVariable assertedValue = (StandardAssertedGraphPropertyVariable) this.properties.get(pn);
+		    	if (Objects.equals(assertedValue.property.predicate, p.relation)) {
+		    		this.properties.put(pn, new StandardProdeduralPropertyVariable(graph, this, assertedValue, p.value));
+		    	} else {
+		    		LOGGER.warn("Ignored attempt to override asserted property {}/{}#{} with a different relation", parent.getURI(graph), name, pn);
+		    	}
 		    } else {
 			    this.properties.put(pn, new StandardConstantGraphPropertyVariable(graph, this, p.relation, p.value) );
 		    }
diff --git a/bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProdeduralPropertyVariable.java b/bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProdeduralPropertyVariable.java
new file mode 100644
index 000000000..a277f5142
--- /dev/null
+++ b/bundles/org.simantics.structural2/src/org/simantics/structural2/variables/StandardProdeduralPropertyVariable.java
@@ -0,0 +1,71 @@
+package org.simantics.structural2.variables;
+
+import org.simantics.databoard.Bindings;
+import org.simantics.databoard.adapter.AdaptException;
+import org.simantics.databoard.binding.Binding;
+import org.simantics.databoard.type.Datatype;
+import org.simantics.db.ReadGraph;
+import org.simantics.db.WriteGraph;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.layer0.variable.StandardAssertedGraphPropertyVariable;
+import org.simantics.db.layer0.variable.ValueAccessor;
+import org.simantics.db.layer0.variable.Variable;
+
+public class StandardProdeduralPropertyVariable extends StandardAssertedGraphPropertyVariable {
+
+	private Object defaultValue;
+
+	public StandardProdeduralPropertyVariable(ReadGraph graph,
+			StandardProceduralChildVariable parent,
+			StandardAssertedGraphPropertyVariable assertedVariable, Object value) throws DatabaseException {
+		super(graph, parent, assertedVariable.node, assertedVariable.parentResource, assertedVariable.property.predicate, assertedVariable.object);
+		
+		this.defaultValue = value;
+	}
+	
+	@Override
+	protected ValueAccessor getValueAccessor(ReadGraph graph) throws DatabaseException {
+		final ValueAccessor valueAccessor = super.getValueAccessor(graph);
+		return new ValueAccessor() {
+			@Override
+			public void setValue(WriteGraph graph, Variable context, Object value, Binding binding) throws DatabaseException {
+				valueAccessor.setValue(graph, context, value, binding);
+			}
+			
+			@Override
+			public void setValue(WriteGraph graph, Variable context, Object value) throws DatabaseException {
+				valueAccessor.setValue(graph, context, value);
+			}
+			
+			@Override
+			public Object getValue(ReadGraph graph, Variable context, Binding binding) throws DatabaseException {
+				if (node != null) {
+					return valueAccessor.getValue(graph, context, binding);
+				} else {
+					if (binding.isInstance(defaultValue))
+						return defaultValue;
+					else
+						try {
+							return Bindings.adapt(defaultValue, Bindings.OBJECT, binding);
+						} catch (AdaptException e) {
+							throw new DatabaseException("Failed to adapt object " + defaultValue + " to " + binding);
+						}
+				}
+			}
+			
+			@Override
+			public Object getValue(ReadGraph graph, Variable context) throws DatabaseException {
+				if (node != null) {
+					return valueAccessor.getValue(graph, context);
+				} else {
+					return defaultValue;
+				}
+			}
+			
+			@Override
+			public Datatype getDatatype(ReadGraph graph, Variable context) throws DatabaseException {
+				return valueAccessor.getDatatype(graph, context);
+			}
+		};
+	}
+}
-- 
2.43.2