unassign_material_style to handle constituents

src/ifcopenshell-python/ifcopenshell/api/style/unassign_material_style.py

@@ -17,6 +17,9 @@
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import ifcopenshell
+
+
 class Usecase:
     def __init__(self, file, material=None, style=None, context=None):
         """Unassigns a style to a material
@@ -67,3 +70,28 @@ class Usecase:
                     self.file.remove(representation)
             if not definition.Representations:
                 self.file.remove(definition)
+
+        # handle material constituents and shape aspects
+        material_constituents_names = []
+        for inverse in self.file.get_inverse(self.settings["material"]):
+            if inverse.is_a("IfcMaterialConstituent") and inverse.Name:
+                material_constituents_names.append(inverse.Name)
+        if not material_constituents_names:
+            return
+
+        elements = ifcopenshell.util.element.get_elements_by_material(self.file, self.settings["material"])
+        shape_aspects = []
+        for element in elements:
+            shape_aspects += ifcopenshell.util.element.get_shape_aspects(element)
+
+        for shape_aspect in shape_aspects:
+            if shape_aspect.Name not in material_constituents_names:
+                continue
+
+            for rep in shape_aspect.ShapeRepresentations:
+                ifcopenshell.api.run(
+                    "style.unassign_representation_styles",
+                    self.file,
+                    shape_representation=rep,
+                    styles=[self.settings["style"]],
+                )

src/ifcopenshell-python/test/api/style/test_unassign_material_style.py

@@ -45,3 +45,37 @@ class TestAssignMaterialStyle(test.bootstrap.IFC4):
         assert len(self.file.by_type("IfcMaterialDefinitionRepresentation")) == 0
         assert len(self.file.by_type("IfcStyledRepresentation")) == 0
         assert len(self.file.by_type("IfcStyledItem")) == 0
+
+    def test_update_shape_aspect_representaitons_items_styles_if_material_is_part_of_matching_material_constituents(
+        self,
+    ):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        name = "Concrete"
+        product_shape = self.file.createIfcProductDefinitionShape()
+        element.Representation = product_shape
+        context = self.file.createIfcGeometricRepresentationContext()
+
+        representation = self.file.createIfcShapeRepresentation()
+        item = self.file.createIfcExtrudedAreaSolid()
+        representation.Items = [item]
+
+        shape_aspect = self.file.createIfcShapeAspect(ShapeRepresentations=(representation,), Name=name)
+        shape_aspect.PartOfProductDefinitionShape = product_shape
+
+        style = self.file.createIfcSurfaceStyle()
+        material = ifcopenshell.api.run("material.add_material", self.file)
+        material_set = ifcopenshell.api.run(
+            "material.add_material_set", self.file, set_type="IfcMaterialConstituentSet"
+        )
+        constituent = ifcopenshell.api.run(
+            "material.add_constituent", self.file, constituent_set=material_set, material=material
+        )
+        constituent.Name = name
+        ifcopenshell.api.run("material.assign_material", self.file, product=element, material=material_set)
+
+        ifcopenshell.api.run("style.assign_material_style", self.file, material=material, style=style, context=context)
+        ifcopenshell.api.run(
+            "style.unassign_material_style", self.file, material=material, style=style, context=context
+        )
+
+        assert len(item.StyledByItem) == 0