ifcpatch: add FixDoubleTypedPredefinedType recipe for OJT001 cleanup

Existing IFC files (Revit exports, or Bonsai models typed before a
type's PredefinedType was set) commonly carry an explicit
PredefinedType/ObjectType on occurrences whose type already has a
concrete PredefinedType, violating buildingSMART rule OJT001. PR #8829
stops this happening going forward at the authoring layer; this recipe
is the one-click cleanup for files that already have the problem.

The "is the type concrete" check mirrors
ifcopenshell.api.type.assign_type and
ifcopenshell.api.attribute.edit_attributes exactly, including the
USERDEFINED nuance (only counts as concrete if the type also carries a
custom description to fall back on), so behaviour stays consistent
between authoring and cleanup. Bonsai's IFC Patch UI discovers recipes
by globbing ifcpatch/recipes/*.py, so no Bonsai UI changes are needed.

Generated with the assistance of an AI coding tool.

src/ifcpatch/ifcpatch/recipes/FixDoubleTypedPredefinedType.py

@@ -0,0 +1,101 @@
+# IfcPatch - IFC patching utiliy
+# Copyright (C) 2020, 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcPatch.
+#
+# IfcPatch is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcPatch is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcPatch.  If not, see <http://www.gnu.org/licenses/>.
+
+# This file was generated with the assistance of an AI coding tool.
+
+from logging import Logger
+from typing import Union
+
+import ifcopenshell
+import ifcopenshell.util.element
+import ifcopenshell.util.selector
+
+import ifcpatch
+
+
+class Patcher(ifcpatch.BasePatcher):
+    def __init__(self, file: ifcopenshell.file, logger: Union[Logger, None] = None, query: str = ""):
+        """Clear an occurrence's PredefinedType/ObjectType when its type is already concrete
+
+        IFC forbids "double typing": if an IfcTypeObject's own PredefinedType
+        is a concrete value (i.e. not NOTDEFINED), the PredefinedType and
+        ObjectType of its typed occurrences must be left empty, since the
+        type already carries that information (buildingSMART rule OJT001).
+
+        Legacy files, or files typed before their type's PredefinedType was
+        set, commonly carry a stray PredefinedType (often NOTDEFINED) or
+        ObjectType on the occurrence anyway. This recipe finds every
+        occurrence typed by a type with a concrete PredefinedType and clears
+        the occurrence's own PredefinedType and ObjectType attributes,
+        without touching untyped occurrences or occurrences of a type that is
+        itself NOTDEFINED (as those may still carry meaningful data of their
+        own).
+
+        The "is the type concrete" check mirrors
+        ifcopenshell.api.type.assign_type and
+        ifcopenshell.api.attribute.edit_attributes: a type whose
+        PredefinedType is USERDEFINED only counts as concrete if it also has
+        a custom type name (e.g. ElementType) to fall back on. This keeps the
+        recipe non-destructive: it will never remove the only description an
+        occurrence has.
+
+        :param query: A query to select the subset of IFC elements to
+            restrict the patch to, optional. If not provided, patch will be
+            applied to all typed occurrences in the model. See
+            ifcopenshell.util.selector for query syntax.
+
+        Example:
+
+        .. code:: python
+
+            # Fix all double-typed occurrences in the model.
+            ifcpatch.execute({"input": "input.ifc", "file": model, "recipe": "FixDoubleTypedPredefinedType"})
+
+            # Only fix double-typed walls.
+            ifcpatch.execute({
+                "input": "input.ifc",
+                "file": model,
+                "recipe": "FixDoubleTypedPredefinedType",
+                "arguments": ["IfcWall"],
+            })
+        """
+        super().__init__(file, logger)
+        self.query = query
+
+    def patch(self):
+        occurrences = None
+        if self.query:
+            occurrences = ifcopenshell.util.selector.filter_elements(self.file, self.query)
+
+        cleared = 0
+        for rel in self.file.by_type("IfcRelDefinesByType"):
+            predefined_type = ifcopenshell.util.element.get_predefined_type(rel.RelatingType)
+            if predefined_type is None or predefined_type == "NOTDEFINED":
+                continue
+            for occurrence in rel.RelatedObjects:
+                if occurrences is not None and occurrence not in occurrences:
+                    continue
+                has_predefined_type = hasattr(occurrence, "PredefinedType")
+                if not occurrence.ObjectType and (not has_predefined_type or not occurrence.PredefinedType):
+                    continue  # Already clean.
+                occurrence.ObjectType = None
+                if has_predefined_type:
+                    occurrence.PredefinedType = None
+                cleared += 1
+
+        self.logger.info(f"Cleared PredefinedType/ObjectType on {cleared} double-typed occurrence(s).")

src/ifcpatch/test/test_FixDoubleTypedPredefinedType.py

@@ -0,0 +1,187 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2026 Petru Conduraru <petru@bimvoice.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+# This file was generated with the assistance of an AI coding tool.
+
+import ifcopenshell.api.root
+import ifcopenshell.api.type
+
+import ifcpatch
+import test.bootstrap
+
+
+class TestFixDoubleTypedPredefinedType(test.bootstrap.IFC4):
+    def test_clears_occurrence_under_concrete_type(self):
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "MOVABLE"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        wall.PredefinedType = "NOTDEFINED"
+        wall.ObjectType = "Some legacy value"
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        # assign_type would already clear these; force them back to simulate
+        # a legacy file where the occurrence was typed before this cleanup
+        # existed.
+        wall.PredefinedType = "NOTDEFINED"
+        wall.ObjectType = "Some legacy value"
+
+        output = ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert wall.PredefinedType is None
+        assert wall.ObjectType is None
+        assert output == self.file
+
+    def test_leaves_occurrence_under_notdefined_type_untouched(self):
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "NOTDEFINED"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        wall.PredefinedType = "MOVABLE"
+        wall.ObjectType = "Legitimate own value"
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        wall.PredefinedType = "MOVABLE"
+        wall.ObjectType = "Legitimate own value"
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert wall.PredefinedType == "MOVABLE"
+        assert wall.ObjectType == "Legitimate own value"
+
+    def test_leaves_untyped_element_untouched(self):
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        wall.PredefinedType = "NOTDEFINED"
+        wall.ObjectType = "Untyped value"
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert wall.PredefinedType == "NOTDEFINED"
+        assert wall.ObjectType == "Untyped value"
+
+    def test_userdefined_type_with_custom_description_clears_occurrence(self):
+        # Mirrors ifcopenshell.api.type.assign_type: a USERDEFINED type only
+        # counts as "concrete" if it also has a custom type name to fall
+        # back on (here IfcWallType.ElementType).
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "USERDEFINED"
+        wall_type.ElementType = "MyCustomWall"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        wall.PredefinedType = "NOTDEFINED"
+        wall.ObjectType = "Some legacy value"
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        wall.PredefinedType = "NOTDEFINED"
+        wall.ObjectType = "Some legacy value"
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert wall.PredefinedType is None
+        assert wall.ObjectType is None
+
+    def test_userdefined_type_without_custom_description_untouched(self):
+        # A USERDEFINED type with no ElementType/ObjectType of its own
+        # carries no real type information, so assign_type leaves the
+        # occurrence alone. This recipe mirrors that.
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "USERDEFINED"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        wall.PredefinedType = "NOTDEFINED"
+        wall.ObjectType = "Kept because type has no description"
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        wall.PredefinedType = "NOTDEFINED"
+        wall.ObjectType = "Kept because type has no description"
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert wall.PredefinedType == "NOTDEFINED"
+        assert wall.ObjectType == "Kept because type has no description"
+
+    def test_already_clean_file_is_a_no_op(self):
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "MOVABLE"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        assert wall.PredefinedType is None
+        assert wall.ObjectType is None
+        before = self.file.to_string()
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert self.file.to_string() == before
+
+    def test_query_restricts_which_occurrences_are_touched(self):
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "MOVABLE"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        wall.PredefinedType = "NOTDEFINED"
+        column_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcColumnType", name="CT1")
+        column_type.PredefinedType = "COLUMN"
+        column = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcColumn")
+        column.PredefinedType = "NOTDEFINED"
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[column], relating_type=column_type, should_map_representations=False
+        )
+        wall.PredefinedType = "NOTDEFINED"
+        column.PredefinedType = "NOTDEFINED"
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": ["IfcWall"]})
+
+        assert wall.PredefinedType is None
+        assert column.PredefinedType == "NOTDEFINED"
+
+
+class TestFixDoubleTypedPredefinedTypeIFC2X3(test.bootstrap.IFC2X3):
+    def test_ifc2x3_occurrence_without_predefined_type_attribute_is_guarded(self):
+        # IFC2X3 IfcWallStandardCase has no PredefinedType attribute at all;
+        # only ObjectType may be cleared there.
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "STANDARD"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallStandardCase")
+        wall.ObjectType = "Some legacy value"
+        assert not hasattr(wall, "PredefinedType")
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        wall.ObjectType = "Some legacy value"
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert wall.ObjectType is None
+
+    def test_ifc2x3_userdefined_type_without_elementtype_untouched(self):
+        wall_type = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType", name="WT1")
+        wall_type.PredefinedType = "USERDEFINED"
+        wall = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallStandardCase")
+        wall.ObjectType = "Kept because type has no description"
+        ifcopenshell.api.type.assign_type(
+            self.file, related_objects=[wall], relating_type=wall_type, should_map_representations=False
+        )
+        wall.ObjectType = "Kept because type has no description"
+
+        ifcpatch.execute({"file": self.file, "recipe": "FixDoubleTypedPredefinedType", "arguments": []})
+
+        assert wall.ObjectType == "Kept because type has no description"