New IfcPatch recipe to fix Revit bug with occurrence based classifications

src/ifcpatch/ifcpatch/recipes/FixRevitClassificationCodeTypes.py

@@ -0,0 +1,51 @@
+# IfcPatch - IFC patching utiliy
+# Copyright (C) 2023 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/>.
+
+import ifcopenshell
+import ifcopenshell.util.element
+
+
+class Patcher:
+    def __init__(self, src, file, logger):
+        """Reassigns occurrence classifications to types
+
+        Revit has a bug (see https://github.com/Autodesk/revit-ifc/issues/691)
+        where it assigns classification codes to occurrences instead of types.
+        Almost always, this is not what you want. This patch reassigns all
+        classifications to their respective types.
+
+        Example:
+
+        .. code:: python
+
+            ifcpatch.execute({"input": model, "recipe": "FixRevitClassificationCodeTypes"})
+        """
+        self.src = src
+        self.file = file
+        self.logger = logger
+
+    def patch(self):
+        for rel in self.file.by_type("IfcRelAssociatesClassification"):
+            related_types = set()
+            for related_object in rel.RelatedObjects:
+                relating_type = ifcopenshell.util.element.get_type(related_object)
+                if relating_type:
+                    related_types.add(relating_type)
+                else:
+                    related_types.add(related_object)
+            rel.RelatedObjects = list(related_types)