You can now remove material sets independent of elements

src/ifcopenshell-python/ifcopenshell/api/material/remove_material_set.py

@@ -0,0 +1,48 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2022 Dion Moult <dion@thinkmoult.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/>.
+
+import ifcopenshell
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"material": None}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        inverse_elements = self.file.get_inverse(self.settings["material"])
+        if self.settings["material"].is_a("IfcMaterialLayerSet"):
+            set_items = self.settings["material"].MaterialLayers or []
+        elif self.settings["material"].is_a("IfcMaterialProfileSet"):
+            set_items = self.settings["material"].MaterialProfiles or []
+        elif self.settings["material"].is_a("IfcMaterialConstituentSet"):
+            set_items = self.settings["material"].MaterialConstituents or []
+        elif self.settings["material"].is_a("IfcMaterialList"):
+            set_items = []
+        for set_item in set_items:
+            self.file.remove(set_item)
+        self.file.remove(self.settings["material"])
+        for inverse in inverse_elements:
+            if inverse.is_a("IfcRelAssociatesMaterial"):
+                self.file.remove(inverse)
+            elif inverse.is_a("IfcMaterialProperties"):
+                for prop in inverse.Properties or []:
+                    self.file.remove(prop)
+                self.file.remove(inverse)