Fix for GitHub Issue 11

Author: juileetikekar

src/AasxCsharpLibrary/Extensions/ExtendReference.cs

@@ -203,6 +203,17 @@ public static string GetAsIdentifier(this IReference reference)
                 return reference.Keys[0].Value;
             }
 
+            //TODO (jtikekar, 2024-03-06): Refactor, added w.r.t. GitHub issue 11
+            if(reference.Type == ReferenceTypes.ModelReference)
+            {
+                if (reference.Keys == null || reference.Keys.Count < 1)
+                {
+                    return null;
+                }
+
+                return reference.Keys[0].Value;
+            }
+
             return null;
         }
 

src/AasxPackageLogic/DispEditHelperEntities.cs

@@ -2702,7 +2702,8 @@ public void DisplayOrEditAasEntitySubmodelElement(
                             if (ks != null)
                             {
                                 // set the semantic id
-                                sme.SemanticId = new Aas.Reference(Aas.ReferenceTypes.ExternalReference, new List<Aas.IKey>(ks));
+                                //Using ModelReference for "Use existing" as this cd is being fetched from model/env
+                                sme.SemanticId = new Aas.Reference(Aas.ReferenceTypes.ModelReference, new List<Aas.IKey>(ks));
 
                                 // if empty take over shortName
                                 var cd = env.FindConceptDescriptionByReference(sme.SemanticId);