Fix #7213. IfcTester now supports checking for USERDEFINED predefined types

Moult · Moult · commit cb5c488cfd33 · 2025-10-11T21:09:41.000+11:00
Can I just take this moment to complain about the overengineered
complexity of how predefined types work in IFC.
diff --git a/src/ifcopenshell-python/ifcopenshell/util/element.py b/src/ifcopenshell-python/ifcopenshell/util/element.py
@@ -565,6 +565,40 @@ def get_predefined_type(element: ifcopenshell.entity_instance) -> Union[str, Non
     return predefined_type
 
 
+def is_userdefined_type(element: ifcopenshell.entity_instance) -> bool:
+    """Checks if the predefined type is userdefined
+
+    :param element: The IFC Element entity
+    :return: True if userdefined
+
+    Example:
+
+    .. code:: python
+
+        element = ifcopenshell.by_type("IfcWall")[0]
+        is_userdefined_type = ifcopenshell.util.element.is_userdefined_type(element)
+    """
+    if element_type := get_type(element):
+        predefined_type = getattr(element_type, "PredefinedType", None)
+        if predefined_type == "USERDEFINED":
+            return True
+        elif not predefined_type:
+            predefined_type = getattr(element_type, "ElementType", ...)
+            if predefined_type == ...:
+                predefined_type = getattr(element_type, "ProcessType", None)
+            if predefined_type:
+                return True
+        if predefined_type and predefined_type != "NOTDEFINED":
+            return False
+
+    predefined_type = getattr(element, "PredefinedType", None)
+    if predefined_type == "USERDEFINED":
+        return True
+    elif not predefined_type:
+        return bool(getattr(element, "ObjectType", None))
+    return False
+
+
 def get_type(element: ifcopenshell.entity_instance) -> Union[ifcopenshell.entity_instance, None]:
     """Retrieves the construction type element of an element occurrence.
 
diff --git a/src/ifcopenshell-python/test/util/test_element.py b/src/ifcopenshell-python/test/util/test_element.py
@@ -369,6 +369,65 @@ def test_getting_an_element_type_null_predefined_type(self):
         assert subject.get_predefined_type(element_type) == "NOTDEFINED"
 
 
+class TestIsUserdefinedTypeIFC4(test.bootstrap.IFC4):
+    def test_getting_a_predefined_element(self):
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        element.PredefinedType = "PARTITIONING"
+        assert not subject.is_userdefined_type(element)
+
+    def test_getting_an_element_userdefined_type(self):
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        element.PredefinedType = "USERDEFINED"
+        element.ObjectType = "FOOBAR"
+        assert subject.is_userdefined_type(element)
+
+    def test_getting_an_element_type_without_a_predefined_type_attribute(self):
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcAnnotation")
+        element.ObjectType = "FOOBAR"
+        assert subject.is_userdefined_type(element)
+
+    def test_getting_an_inherited_predefined_type(self):
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        element_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType")
+        ifcopenshell.api.type.assign_type(self.file, related_objects=[element], relating_type=element_type)
+        element_type.PredefinedType = "PARTITIONING"
+        assert not subject.is_userdefined_type(element)
+
+    def test_getting_an_inherited_userdefined_type_for_an_element_type(self):
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        element_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType")
+        ifcopenshell.api.type.assign_type(self.file, related_objects=[element], relating_type=element_type)
+        element_type.PredefinedType = "USERDEFINED"
+        element_type.ElementType = "FOOBAR"
+        assert subject.is_userdefined_type(element)
+
+    def test_getting_an_overriden_predefined_type(self):
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        element_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType")
+        ifcopenshell.api.type.assign_type(self.file, related_objects=[element], relating_type=element_type)
+        element_type.PredefinedType = "NOTDEFINED"
+        element.PredefinedType = "PARTITIONING"
+        assert not subject.is_userdefined_type(element)
+
+    def test_getting_an_inherited_userdefined_type_for_a_process_type(self):
+        element = ifcopenshell.api.sequence.add_task(self.file)
+        element_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcTaskType")
+        ifcopenshell.api.type.assign_type(self.file, related_objects=[element], relating_type=element_type)
+        element_type.PredefinedType = "USERDEFINED"
+        element_type.ProcessType = "FOOBAR"
+        assert subject.is_userdefined_type(element)
+
+    def test_getting_an_element_type_predefined_type(self):
+        element_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType")
+        element_type.PredefinedType = "PARTITIONING"
+        assert not subject.is_userdefined_type(element_type)
+
+    def test_getting_an_element_type_null_predefined_type(self):
+        element_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType")
+        element_type.PredefinedType = "NOTDEFINED"
+        assert not subject.is_userdefined_type(element_type)
+
+
 class TestGetTypeIFC4(test.bootstrap.IFC4):
     def test_getting_the_type_of_a_product(self):
         element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
diff --git a/src/ifctester/ifctester/facet.py b/src/ifctester/ifctester/facet.py
@@ -227,8 +227,13 @@ def __call__(self, inst: ifcopenshell.entity_instance, logger: Optional[Logger]
             reason = {"type": "NAME", "actual": inst.is_a().upper()}
 
         if is_pass and self.predefinedType:
-            predefined_type = ifcopenshell.util.element.get_predefined_type(inst)
-            is_pass = predefined_type == self.predefinedType
+            if self.predefinedType == "USERDEFINED":
+                is_pass = ifcopenshell.util.element.is_userdefined_type(inst)
+                if not is_pass:
+                    predefined_type = ifcopenshell.util.element.get_predefined_type(inst)
+            else:
+                predefined_type = ifcopenshell.util.element.get_predefined_type(inst)
+                is_pass = predefined_type == self.predefinedType
 
             if not is_pass:
                 reason = {"type": "PREDEFINEDTYPE", "actual": predefined_type}
diff --git a/src/ifctester/test/test_facet.py b/src/ifctester/test/test_facet.py
@@ -172,10 +172,10 @@ def test_filtering_using_an_entity_facet(self):
         facet = Entity(name="IFCWALL", predefinedType="USERDEFINED")
         ifc = ifcopenshell.file()
         run(
-            "A predefined type must always specify a meaningful type, not USERDEFINED itself",
+            "A predefined type may specify USERDEFINED itself",
             facet=facet,
             inst=ifc.createIfcWall(PredefinedType="USERDEFINED", ObjectType="WALDO"),
-            expected=False,
+            expected=True,
         )
 
         ifc = ifcopenshell.file()
