External resource relationships are now also purged when removing classifications

src/ifcopenshell-python/ifcopenshell/api/classification/remove_classification.py

@@ -32,6 +32,9 @@ class Usecase:
         for rel in self.file.by_type("IfcRelAssociatesClassification"):
             if not rel.RelatingClassification:
                 self.file.remove(rel)
+        for rel in self.file.by_type("IfcExternalReferenceRelationship"):
+            if not rel.RelatingReference:
+                self.file.remove(rel)
 
     def get_references(self, classification):
         results = []

src/ifcopenshell-python/test/api/classification/test_remove_classification.py

@@ -0,0 +1,62 @@
+# 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 test.bootstrap
+import ifcopenshell.api
+
+
+class TestRemoveClassification(test.bootstrap.IFC4):
+    def test_removing_a_classification(self):
+        ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
+        element = ifcopenshell.api.run("classification.add_classification", self.file, classification="Name")
+        ifcopenshell.api.run("classification.remove_classification", self.file, classification=element)
+        assert not self.file.by_type("IfcClassification")
+
+    def test_removing_a_classification_and_all_of_its_references(self):
+        ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
+        result = ifcopenshell.api.run("classification.add_classification", self.file, classification="Name")
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run(
+            "classification.add_reference",
+            self.file,
+            product=element,
+            identification="X",
+            name="Foobar",
+            classification=result,
+        )
+        ifcopenshell.api.run("classification.remove_classification", self.file, classification=result)
+        assert not self.file.by_type("IfcClassification")
+        assert not self.file.by_type("IfcClassificationReference")
+        assert not self.file.by_type("IfcRelAssociatesClassification")
+
+    def test_removing_a_classification_and_all_of_its_references_when_associated_with_a_resource(self):
+        ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
+        result = ifcopenshell.api.run("classification.add_classification", self.file, classification="Name")
+        element = self.file.createIfcMaterial(Name="Material")
+        ifcopenshell.api.run(
+            "classification.add_reference",
+            self.file,
+            product=element,
+            identification="X",
+            name="Foobar",
+            classification=result,
+        )
+        ifcopenshell.api.run("classification.remove_classification", self.file, classification=result)
+        assert not self.file.by_type("IfcClassification")
+        assert not self.file.by_type("IfcClassificationReference")
+        assert not self.file.by_type("IfcExternalReferenceRelationship")