Assigning library references now works on IFC2X3.

src/ifcopenshell-python/ifcopenshell/api/library/assign_reference.py

@@ -12,7 +12,10 @@ class Usecase:
             self.settings[key] = value
 
     def execute(self):
-        rels = self.settings["reference"].LibraryRefForObjects
+        if self.file.schema == "IFC2X3":
+            rels = self.get_ifc2x3_rels()
+        else:
+            rels = self.settings["reference"].LibraryRefForObjects
         if not rels:
             return self.file.create_entity(
                 "IfcRelAssociatesLibrary",
@@ -32,3 +35,8 @@ class Usecase:
         rel.RelatedObjects = related_objects
         ifcopenshell.api.run("owner.update_owner_history", self.file, element=rel)
         return rel
+
+    def get_ifc2x3_rels(self):
+        return [
+            r for r in self.file.by_type("IfcRelAssociatesLibrary") if r.RelatingLibrary == self.settings["reference"]
+        ]

src/ifcopenshell-python/test/api/library/test_assign_reference.py

@@ -18,3 +18,23 @@ class TestAssignReference(test.bootstrap.IFC4):
         ifcopenshell.api.run("library.assign_reference", self.file, product=product, reference=reference)
         ifcopenshell.api.run("library.assign_reference", self.file, product=product, reference=reference)
         assert reference.LibraryRefForObjects[0].RelatedObjects == (product,)
+
+
+class TestAssignReference(test.bootstrap.IFC2X3):
+    def test_assigning_a_reference(self):
+        reference = self.file.createIfcLibraryReference()
+        product = self.file.createIfcWall()
+        product2 = self.file.createIfcWall()
+        ifcopenshell.api.run("library.assign_reference", self.file, product=product, reference=reference)
+        rel = self.file.by_type("IfcRelAssociatesLibrary")[0]
+        assert rel.RelatedObjects == (product,)
+        ifcopenshell.api.run("library.assign_reference", self.file, product=product2, reference=reference)
+        assert rel.RelatedObjects == (product, product2)
+
+    def test_not_assigning_twice(self):
+        reference = self.file.createIfcLibraryReference()
+        product = self.file.createIfcWall()
+        ifcopenshell.api.run("library.assign_reference", self.file, product=product, reference=reference)
+        ifcopenshell.api.run("library.assign_reference", self.file, product=product, reference=reference)
+        rel = self.file.by_type("IfcRelAssociatesLibrary")[0]
+        assert rel.RelatedObjects == (product,)