Fix #4696. Null properties are now purged by default to prevent cruft build up. Add support for purging empty enum props.

src/ifcopenshell-python/ifcopenshell/api/pset/edit_pset.py

@@ -27,7 +27,7 @@ def edit_pset(
     name: Optional[str] = None,
     properties: Optional[dict[str, Any]] = None,
     pset_template: Optional[ifcopenshell.entity_instance] = None,
-    should_purge: bool = False,
+    should_purge: bool = True,
 ) -> None:
     """Edits a property set and its properties
 
@@ -77,9 +77,10 @@ def edit_pset(
         be used to determine data types. If no user-defined template is
         provided, the built-in buildingSMART templates will be loaded.
     :type pset_template: ifcopenshell.entity_instance, optional
-    :param should_purge: If left as False, properties set to None will be
+    :param should_purge: If set as False, properties set to None will be
         left as None but not removed. If set to true, properties set to None
-        will actually be removed.
+        will actually be removed. The default of true is the same behaviour as
+        :func:`ifcopenshell.api.pset.edit_qto`.
     :type should_purge: bool, optional
     :return: None
     :rtype: None
@@ -241,6 +242,9 @@ class Usecase:
 
         if isinstance(value, (tuple, list)):
             sel_vals = []
+            if not value:
+                if self._try_purge(prop):
+                    return
             for val in value:
                 primary_measure_type = prop.EnumerationReference.EnumerationValues[
                     0

src/ifcopenshell-python/test/api/pset/test_edit_pset.py

@@ -59,7 +59,9 @@ class TestEditPset(test.bootstrap.IFC4):
             pset=pset,
             properties={"Reference": "foo", "Status": ["NEW"], "Combustible": True, "ThermalTransmittance": 42},
         )
-        ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, properties={"Reference": "bar", "Status": []})
+        ifcopenshell.api.run(
+            "pset.edit_pset", self.file, pset=pset, properties={"Reference": "bar", "Status": []}, should_purge=False
+        )
         pset = element.IsDefinedBy[0].RelatingPropertyDefinition
 
         assert pset.HasProperties[0].Name == "Reference"
@@ -88,8 +90,7 @@ class TestEditPset(test.bootstrap.IFC4):
     def test_adding_a_property_if_it_is_none(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
         pset = ifcopenshell.api.run("pset.add_pset", self.file, product=element, name="Pset_WallCommon")
-        # should_purge is false by default
-        ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, properties={"Reference": None})
+        ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, properties={"Reference": None}, should_purge=False)
         pset = element.IsDefinedBy[0].RelatingPropertyDefinition
         assert len(pset.HasProperties) == 1
 
@@ -108,6 +109,16 @@ class TestEditPset(test.bootstrap.IFC4):
         pset = element.IsDefinedBy[0].RelatingPropertyDefinition
         assert len(pset.HasProperties) == 0
 
+    def test_removing_a_none_enumeration_property_if_specified(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        pset = ifcopenshell.api.run("pset.add_pset", self.file, product=element, name="Pset_WallCommon")
+        ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, properties={"Status": ["NEW"]})
+        assert pset.HasProperties[0].Name == "Status"
+        assert pset.HasProperties[0].EnumerationValues[0].wrappedValue == "NEW"
+        ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, properties={"Status": []}, should_purge=True)
+        pset = element.IsDefinedBy[0].RelatingPropertyDefinition
+        assert len(pset.HasProperties) == 0
+
     def test_editing_a_pset_name(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
         pset = ifcopenshell.api.run("pset.add_pset", self.file, product=element, name="foo")