assign_type not to remap if it's type was assigned previously

src/ifcopenshell-python/ifcopenshell/api/type/assign_type.py

@@ -19,7 +19,7 @@
 import ifcopenshell
 import ifcopenshell.api
 import ifcopenshell.util.element
-from typing import Union
+from typing import Union, Iterable
 
 
 class Usecase:
@@ -98,6 +98,7 @@ class Usecase:
             IFC requires all occurrences to map those representations. Some IFC
             vendors might disobey this, or you might want to handle it
             yourself. In this scenario, you may set this to False.
+            This also enabled adding material usages mapping.
         :type should_map_representations: bool
         :return: The IfcRelDefinesByType relationship
             or `None` if `related_objects` was empty list.
@@ -250,17 +251,17 @@ class Usecase:
 
         if self.settings["should_map_representations"]:
             if getattr(relating_type, "RepresentationMaps", None):
-                for related_object in related_objects:
+                for related_object in objects_to_change:
                     ifcopenshell.api.run(
                         "type.map_type_representations",
                         self.file,
                         related_object=related_object,
                         relating_type=relating_type,
                     )
-            self.map_material_usages(related_objects)
+            self.map_material_usages(objects_to_change)
         return types
 
-    def map_material_usages(self, related_objects: set[ifcopenshell.entity_instance]) -> None:
+    def map_material_usages(self, related_objects: Iterable[ifcopenshell.entity_instance]) -> None:
         type_material = ifcopenshell.util.element.get_material(self.settings["relating_type"])
         if not type_material:
             return

src/ifcopenshell-python/test/api/type/test_assign_type.py

@@ -19,6 +19,7 @@
 import test.bootstrap
 import ifcopenshell.api
 import ifcopenshell.util.element
+import ifcopenshell.util.representation
 import pytest
 
 
@@ -65,6 +66,83 @@ class TestAssignType(test.bootstrap.IFC4):
         with pytest.raises(RuntimeError):
             self.file.by_id(rel_id)
 
+    def test_map_representation_disabled(self):
+        element_type = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWallType")
+        context = self.file.createIfcGeometricRepresentationContext()
+        rep = self.file.createIfcShapeRepresentation(ContextOfItems=context)
+        ifcopenshell.api.run("geometry.assign_representation", self.file, product=element_type, representation=rep)
+        ifcopenshell.api.run("material.assign_material", self.file, product=element_type, type="IfcMaterialLayerSet")
+
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run(
+            "type.assign_type",
+            self.file,
+            related_objects=[element],
+            relating_type=element_type,
+            should_map_representations=False,
+        )
+
+        # no representation mapping and no material usage
+        assert ifcopenshell.util.representation.get_representation(element, context=context) == None
+        assert ifcopenshell.util.element.get_material(element, should_inherit=False) == None
+
+    def test_map_representation(self):
+        element_type = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWallType")
+        context = self.file.createIfcGeometricRepresentationContext()
+        rep = self.file.createIfcShapeRepresentation(ContextOfItems=context)
+        ifcopenshell.api.run("geometry.assign_representation", self.file, product=element_type, representation=rep)
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("type.assign_type", self.file, related_objects=[element], relating_type=element_type)
+        mapped_rep = ifcopenshell.util.representation.get_representation(element, context=context)
+        assert mapped_rep.RepresentationType == "MappedRepresentation"
+        assert mapped_rep.Items[0].MappingSource.MappedRepresentation == rep
+
+    def test_map_representation(self):
+        element_type = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWallType")
+        context = self.file.createIfcGeometricRepresentationContext()
+        rep = self.file.createIfcShapeRepresentation(ContextOfItems=context)
+        ifcopenshell.api.run("geometry.assign_representation", self.file, product=element_type, representation=rep)
+        element1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("type.assign_type", self.file, related_objects=[element1], relating_type=element_type)
+        assert (mapped_rep := ifcopenshell.util.representation.get_representation(element1, context=context))
+        mapped_rep_id = mapped_rep.id()
+
+        element2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run(
+            "type.assign_type", self.file, related_objects=[element1, element2], relating_type=element_type
+        )
+        assert (mapped_rep := ifcopenshell.util.representation.get_representation(element1, context=context))
+        assert mapped_rep.id() == mapped_rep_id
+
+    def test_map_material_usages(self):
+        material_types = ("IfcMaterialLayerSet",)
+        if self.file.schema != "IFC2X3":
+            material_types += ("IfcMaterialProfileSet",)
+        for material_type in material_types:
+            element_type = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWallType")
+            ifcopenshell.api.run("material.assign_material", self.file, product=element_type, type=material_type)
+            element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+            ifcopenshell.api.run("type.assign_type", self.file, related_objects=[element], relating_type=element_type)
+            material = ifcopenshell.util.element.get_material(element)
+            assert material
+            assert material.is_a(f"{material_type}Usage")
+
+    def test_do_not_reassign_material_if_it_was_assigned_previously(self):
+        element1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        element_type = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWallType")
+        ifcopenshell.api.run("material.assign_material", self.file, product=element_type, type="IfcMaterialLayerSet")
+        ifcopenshell.api.run("type.assign_type", self.file, related_objects=[element1], relating_type=element_type)
+        assert (material := ifcopenshell.util.element.get_material(element1))
+        material_id = material.id()
+
+        # use 2 elements to trigger material assignment code block
+        element2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run(
+            "type.assign_type", self.file, related_objects=[element1, element2], relating_type=element_type
+        )
+        assert (material := ifcopenshell.util.element.get_material(element1))
+        assert material.id() == material_id
+
 
 class TestAssignTypeIFC2X3(test.bootstrap.IFC2X3, TestAssignType):
     pass