From: Antti Villberg <antti.villberg@semantum.fi>
Date: Fri, 16 Nov 2018 13:10:03 +0000 (+0200)
Subject: Utility function for claiming literals
X-Git-Tag: v1.43.0~136^2~264^2
X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F64%2F2464%2F1;p=simantics%2Fplatform.git

Utility function for claiming literals

gitlab #204

Change-Id: Ie1738b7400d26aa05bd889e2853362145cc87adc
---

diff --git a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/util/Layer0Utils.java b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/util/Layer0Utils.java
index ee97fdb58..d89d71652 100644
--- a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/util/Layer0Utils.java
+++ b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/util/Layer0Utils.java
@@ -927,6 +927,27 @@ public class Layer0Utils {
 		return stm != null && stm.isAsserted(subject);
 	}
 
+	/*
+	 * Works around problems in WriteGraph methods with similar signature. 
+	 * Especially handles better some cases with existing literals.
+	 * 
+	 */
+	public static void claimLiteral(WriteGraph graph, Resource r, Resource p, Resource i, Resource t, Object value, Binding binding) throws DatabaseException {
+	    Statement stm = graph.getPossibleStatement(r, p);
+	    if(stm != null && !stm.isAsserted(r)) {
+	        if(graph.isInstanceOf(stm.getObject(), t)) {
+	            // Existing statement is compatible, reuse the literal
+	            graph.claimValue(stm.getObject(), value, binding);
+	            return;
+	        } else {
+	            // Existing statement is incompatible - remove it
+	            graph.deny(stm);
+	        }
+	    }
+	    // Create new statement
+	    graph.claimLiteral(r, p, i, t, value, binding);
+	}
+	
 	public static void setExpression(WriteGraph graph, Variable context, String text, Resource expressionValueType) throws DatabaseException {
 		
 		Resource value = context.getRepresents(graph);