[1852] Do not propose the "Duplicate Element" node action on Relationships

CHANGELOG.adoc

@@ -51,6 +51,7 @@ This fix ensure that imported models containing, for example, a top-level `Libra
 - https://github.com/eclipse-syson/syson/issues/1825[#1825] [export] `LiteralRational` value wrongly rounded during textual export.
 - https://github.com/eclipse-syson/syson/issues/1784[#1784] [export] Error while exporting `FeatureValue` using enumeration literals.
 - https://github.com/eclipse-syson/syson/issues/1838[#1838] [metamodel] Invalid computation of `Usage.getType`: The subsetted features should be taken into account.
+- https://github.com/eclipse-syson/syson/issues/1852[#1852] [diagrams] Do not propose the _Duplicate Element_ node action on elements which do not support it
 
 === Improvements
 

backend/views/syson-diagram-common-view/src/main/java/org/eclipse/syson/diagram/common/view/nodes/AbstractNodeDescriptionProvider.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2023, 2025 Obeo.
+ * Copyright (c) 2023, 2026 Obeo.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
@@ -31,6 +31,7 @@
 import org.eclipse.sirius.components.view.diagram.provider.DefaultToolsFactory;
 import org.eclipse.sirius.components.view.emf.diagram.ViewDiagramDescriptionConverter;
 import org.eclipse.syson.diagram.services.aql.DiagramMutationAQLService;
+import org.eclipse.syson.util.AQLConstants;
 import org.eclipse.syson.util.AQLUtils;
 import org.eclipse.syson.util.ServiceMethod;
 import org.eclipse.syson.util.StandardDiagramsConstants;
@@ -96,6 +97,7 @@ protected NodeTool getDuplicateElementAndNodeTool() {
         return this.diagramBuilderHelper.newNodeTool()
                 .name("Duplicate Element")
                 .iconURLsExpression("/images/content_copy.svg")
+                .preconditionExpression(AQLConstants.AQL + "self.oclIsKindOf(sysml::Element) and not self.oclIsKindOf(sysml::Relationship)")
                 .body(this.viewBuilderHelper.newChangeContext()
                         .expression(
                                 ServiceMethod.of4(DiagramMutationAQLService::duplicateElementAndExpose)

doc/content/modules/user-manual/pages/release-notes/2026.1.0.adoc

@@ -27,6 +27,11 @@ a|image::explorer-duplicate-object-dialog.png[Duplicate Object dialog, width=40%
 
 - A new tool is available in the palette of diagram graphical nodes to duplicate the graphical node and its semantic `Element`.
 
+[NOTE]
+====
+This action is not available on `Relationships`.
+====
+
 image::manage-elements-duplicate-from-diagram.png[Duplicate element from Diagram, width=40%,height=40%]
 
 - In diagrams, a new graphical edge tool is available to create binary `ConnectionUsage` between `Usages`.