typing

src/bonsai/bonsai/bim/module/drawing/handler.py

@@ -38,18 +38,17 @@ def depsgraph_update_pre_handler(scene):
 
 def set_active_camera_resolution(scene: bpy.types.Scene) -> None:
     props = tool.Drawing.get_document_props()
-    if not scene.camera or "/" not in scene.camera.name or not props.drawings:
+    camera_obj = scene.camera
+    if not camera_obj or "/" not in camera_obj.name or not props.drawings:
         return
-    assert isinstance(scene.camera.data, bpy.types.Camera)
+    assert isinstance((camera := camera_obj.data), bpy.types.Camera)
-    props = scene.camera.data.BIMCameraProperties
+    props = tool.Drawing.get_camera_props(camera)
     ortho_scale = max((props.width, props.height))
     aspect_ratio = props.width / props.height
-    if (scene.camera.data.ortho_scale != ortho_scale) or (
+    if (camera.ortho_scale != ortho_scale) or (scene.render.resolution_x / scene.render.resolution_y != aspect_ratio):
-        scene.render.resolution_x / scene.render.resolution_y != aspect_ratio
+        camera.ortho_scale = ortho_scale
-    ):
-        scene.camera.data.ortho_scale = ortho_scale
 
-        diagram_scale = tool.Drawing.get_diagram_scale(scene.camera)
+        diagram_scale = tool.Drawing.get_diagram_scale(camera_obj)
         scale_ratio = tool.Drawing.get_scale_ratio(diagram_scale["Scale"])
 
         if props.width > props.height:
@@ -61,5 +60,5 @@ def set_active_camera_resolution(scene: bpy.types.Scene) -> None:
             raster_x = ortho_scale * aspect_ratio * scale_ratio * props.dpi / 0.0254
             raster_y = ortho_scale * scale_ratio * props.dpi / 0.0254
 
-        scene.render.resolution_x = scene.camera.data.BIMCameraProperties.raster_x = int(raster_x)
+        scene.render.resolution_x = props.raster_x = int(raster_x)
-        scene.render.resolution_y = scene.camera.data.BIMCameraProperties.raster_y = int(raster_y)
+        scene.render.resolution_y = props.raster_y = int(raster_y)

src/bonsai/bonsai/bim/module/drawing/helper.py

@@ -413,12 +413,13 @@ def get_project_collection(scene):
     return colls[0]
 
 
-def parse_diagram_scale(camera):
+def parse_diagram_scale(camera: bpy.types.Camera) -> float:
     """Returns numeric value of scale"""
-    if camera.BIMCameraProperties.diagram_scale == "CUSTOM":
+    props = tool.Drawing.get_camera_props(camera)
-        _, fraction = camera.BIMCameraProperties.custom_diagram_scale.split("|")
+    if props.diagram_scale == "CUSTOM":
+        _, fraction = props.custom_diagram_scale.split("|")
     else:
-        _, fraction = camera.BIMCameraProperties.diagram_scale.split("|")
+        _, fraction = props.diagram_scale.split("|")
     numerator, denominator = fraction.split("/")
     return float(numerator) / float(denominator)
 
@@ -431,12 +432,11 @@ def ortho_view_frame(
     Similar to `bpy.types.Camera.view_frame`
 
     :arg camera: camera of drawing
-    :type camera: bpy.types.Camera + BIMCameraProperties
     :arg margin: margins, in scene units
-    :type margin: float
     :return: (xmin, xmax, ymin, ymax, zmin, zmax) in local camera coordinates
     """
-    aspect = camera.BIMCameraProperties.raster_y / camera.BIMCameraProperties.raster_x
+    props = tool.Drawing.get_camera_props(camera)
+    aspect = props.raster_y / props.raster_x
     size = camera.ortho_scale
     hwidth = size * 0.5
     hheight = size * 0.5 * aspect

src/bonsai/bonsai/bim/module/drawing/operator.py

@@ -228,7 +228,9 @@ class CreateDrawing(bpy.types.Operator):
         if not tool.Drawing.is_drawing_active():
             cls.poll_message_set("No active drawing.")
             return False
-        if context.scene.camera.data.BIMCameraProperties.linework_mode == "FREESTYLE" and not hasattr(
+        assert context.scene
+        assert (camera_obj := context.scene.camera)
+        if tool.Drawing.get_camera_props(camera_obj).linework_mode == "FREESTYLE" and not hasattr(
             context.scene, "svg_export"
         ):
             cls.poll_message_set(
@@ -248,6 +250,7 @@ class CreateDrawing(bpy.types.Operator):
 
     def execute(self, context):
         self.props = tool.Drawing.get_document_props()
+        assert context.scene and context.scene.camera
 
         active_drawing_id = tool.Blender.get_ifc_definition_id(context.scene.camera)
         if self.print_all:
@@ -262,13 +265,14 @@ class CreateDrawing(bpy.types.Operator):
                 bpy.ops.bim.activate_drawing(drawing=drawing_id, should_view_from_camera=False)
 
             self.camera = context.scene.camera
-            self.camera_element = tool.Ifc.get_entity(self.camera)
+            assert (camera_element := tool.Ifc.get_entity(self.camera))
+            self.camera_element = camera_element
             self.camera_document = tool.Drawing.get_drawing_document(self.camera_element)
             self.file = tool.Ifc.get()
 
             with profile("Drawing generation process"):
                 with profile("Initialize drawing generation process"):
-                    self.cprops = self.camera.data.BIMCameraProperties
+                    self.cprops = tool.Drawing.get_camera_props(self.camera)
                     self.drawing = self.file.by_id(drawing_id)
                     self.drawing_name = self.drawing.Name
                     self.metadata = tool.Drawing.get_drawing_metadata(self.camera_element)
@@ -297,11 +301,11 @@ class CreateDrawing(bpy.types.Operator):
 
                 with profile("Generate linework"):
                     if tool.Drawing.is_camera_orthographic():
-                        if self.camera.data.BIMCameraProperties.linework_mode == "OPENCASCADE":
+                        if self.cprops.linework_mode == "OPENCASCADE":
                             linework_svg = self.generate_linework(context)
-                        elif self.camera.data.BIMCameraProperties.linework_mode == "FREESTYLE":
+                        elif self.cprops.linework_mode == "FREESTYLE":
                             linework_svg = self.generate_freestyle_linework(context)
-                    elif self.camera.data.BIMCameraProperties.linework_mode == "FREESTYLE":
+                    elif self.cprops.linework_mode == "FREESTYLE":
                         linework_svg = self.generate_freestyle_linework(context)
 
                 with profile("Generate annotation"):
@@ -876,19 +880,19 @@ class CreateDrawing(bpy.types.Operator):
 
             return svg_path
 
-        if self.camera.data.BIMCameraProperties.cut_mode == "BISECT":
+        if self.cprops.cut_mode == "BISECT":
             self.remove_cut_linework(root)
             self.generate_bisect_linework(context, root)
             self.generate_wall_layers(context, root)
             self.merge_linework_and_add_metadata(root)
             self.move_elements_to_top(root)
-        elif self.camera.data.BIMCameraProperties.cut_mode == "OPENCASCADE":
+        elif self.cprops.cut_mode == "OPENCASCADE":
             self.move_projection_to_bottom(root)
             self.generate_wall_layers(context, root)
             self.merge_linework_and_add_metadata(root)
             self.move_elements_to_top(root)
 
-        if self.camera.data.BIMCameraProperties.fill_mode == "SHAPELY":
+        if self.cprops.fill_mode == "SHAPELY":
             # shapely variant
             group = root.find("{http://www.w3.org/2000/svg}g")
 
@@ -960,7 +964,7 @@ class CreateDrawing(bpy.types.Operator):
                             path.set("class", " ".join(list(classes)))
                             group.insert(0, path)
 
-        if self.camera.data.BIMCameraProperties.fill_mode == "SVGFILL":
+        if self.cprops.fill_mode == "SVGFILL":
             results = etree.tostring(root).decode("utf8")
             svg_data_1 = results
             from xml.dom.minidom import parseString
@@ -1449,10 +1453,9 @@ class CreateDrawing(bpy.types.Operator):
                 g.set("class", " ".join(list(classes)))
                 group.append(g)
 
-    def drawing_to_model_co(self, x, y):
+    def drawing_to_model_co(self, x: float, y: float) -> Vector:
         camera_xy = np.array((x, -y)) / self.scale / 1000
-        camera_props = self.camera.data.BIMCameraProperties
+        camera_xy += np.array((self.cprops.width / -2, self.cprops.height / 2))  # top left offset
-        camera_xy += np.array((camera_props.width / -2, camera_props.height / 2))  # top left offset
         return self.camera.matrix_world @ Vector(camera_xy).to_3d()
 
     def pythonize(self, arr):
@@ -2158,7 +2161,7 @@ class ActivateDrawingBase:
 
         # Save drawing bounds to the .ifc file
         camera = context.scene.camera
-        camera_props = camera.data.BIMCameraProperties
+        camera_props = tool.Drawing.get_camera_props(camera)
         if camera_props.update_representation(camera):
             bpy.ops.bim.update_representation(obj=camera.name, ifc_representation_class="")
         # See 6452 and 6478.
@@ -2298,7 +2301,8 @@ class ReloadDrawingStyles(bpy.types.Operator):
         if not DrawingsData.is_loaded:
             DrawingsData.load()
         drawing_pset_data = DrawingsData.data["active_drawing_pset_data"]
-        camera_props = context.scene.camera.data.BIMCameraProperties
+        assert context.scene and (camera := context.scene.camera)
+        camera_props = tool.Drawing.get_camera_props(camera)
 
         # added this part as a temporary fallback
         # TODO: should remove it a bit later when projects get more accommodated
@@ -2365,12 +2369,14 @@ class AddDrawingStyle(bpy.types.Operator, tool.Ifc.Operator):
     bl_options = {"REGISTER", "UNDO"}
 
     def execute(self, context):
+        assert context.scene and (camera_obj := context.scene.camera)
         props = tool.Drawing.get_document_props()
         drawing_styles = props.drawing_styles
         new = drawing_styles.add()
         # drawing style is saved to ifc on rename
         new.name = tool.Blender.ensure_unique_name("New Drawing Style", drawing_styles)
-        context.scene.camera.data.BIMCameraProperties.active_drawing_style_index = len(drawing_styles) - 1
+        camera_props = tool.Drawing.get_camera_props(camera_obj)
+        camera_props.active_drawing_style_index = len(drawing_styles) - 1
         return {"FINISHED"}
 
 
@@ -2381,9 +2387,11 @@ class RemoveDrawingStyle(bpy.types.Operator, tool.Ifc.Operator):
     index: bpy.props.IntProperty()
 
     def execute(self, context):
+        assert context.scene and (camera_obj := context.scene.camera)
         props = tool.Drawing.get_document_props()
         props.drawing_styles.remove(self.index)
-        context.scene.camera.data.BIMCameraProperties.active_drawing_style_index = max(self.index - 1, 0)
+        camera_props = tool.Drawing.get_camera_props(camera_obj)
+        camera_props.active_drawing_style_index = max(self.index - 1, 0)
         bpy.ops.bim.save_drawing_styles_data()
         return {"FINISHED"}
 

src/bonsai/bonsai/bim/module/drawing/prop.py

@@ -522,9 +522,34 @@ class BIMCameraProperties(PropertyGroup):
     exclude_filter_groups: CollectionProperty(type=BIMFilterGroup, name="Exclude Filter")
     update_props: BoolProperty(name="Enable Props Auto Update", default=True)
 
+    if TYPE_CHECKING:
+        linework_mode: Literal["OPENCASCADE", "FREESTYLE"]
+        fill_mode: Literal["NONE", "SHAPELY", "SVGFILL"]
+        cut_mode: Literal["BISECT", "OPENCASCADE"]
+        has_underlay: bool
+        has_linework: bool
+        has_annotation: bool
+        representation: str
+        view_name: str
+        diagram_scale: str
+        custom_scale_numerator: str
+        custom_scale_denominator: str
+        raster_x: int
+        raster_y: int
+        dpi: int
+        width: float
+        height: float
+        is_nts: bool
+        active_drawing_style_index: int
+        filter_mode: str
+        include_filter_groups: bpy.types.bpy_prop_collection_idprop[BIMFilterGroup]
+        exclude_filter_groups: bpy.types.bpy_prop_collection_idprop[BIMFilterGroup]
+        update_props: bool
+
     # For now, this JSON dump are all the parameters that determine a camera's "Block representation"
     # By checking this, you will know whether or not the camera IFC representation needs to be refreshed
-    def update_representation(self, obj):
+    def update_representation(self, obj: bpy.types.Object) -> bool:
+        assert isinstance(obj.data, bpy.types.Camera)
         representation = json.dumps(
             {
                 "matrix": [list(x) for x in obj.matrix_world],

src/bonsai/bonsai/bim/module/project/operator.py

@@ -1192,6 +1192,9 @@ class LinkIfc(bpy.types.Operator, ImportHelper):
         filepath: str
         files: list[bpy.types.OperatorFileListElement]
         directory: str
+        filter_glob: str
+        use_relative_path: bool
+        use_cache: bool
 
     def draw(self, context):
         pprops = tool.Project.get_project_props()

src/bonsai/bonsai/tool/blender.py

@@ -82,7 +82,7 @@ class Blender(bonsai.core.tool.Blender):
     @classmethod
     def activate_camera(cls, obj: bpy.types.Object) -> None:
 
-        area = tool.Blender.get_view3d_area()
+        area = cls.get_view3d_area()
         is_local_view = area.spaces[0].local_view is not None
 
         if is_local_view:
@@ -206,7 +206,7 @@ class Blender(bonsai.core.tool.Blender):
         if context is None:
             context = bpy.context
         if obj_type == "Object":
-            props = tool.Blender.get_object_bim_props(bpy.data.objects[obj])
+            props = cls.get_object_bim_props(bpy.data.objects[obj])
             return props.ifc_definition_id
         elif obj_type == "Material":
             props = tool.Material.get_material_props()
@@ -239,7 +239,7 @@ class Blender(bonsai.core.tool.Blender):
 
     @classmethod
     def is_ifc_object(cls, obj: bpy.types.Object) -> bool:
-        props = tool.Blender.get_object_bim_props(obj)
+        props = cls.get_object_bim_props(obj)
         return bool(props.ifc_definition_id)
 
     @classmethod
@@ -338,7 +338,7 @@ class Blender(bonsai.core.tool.Blender):
 
     @classmethod
     def set_viewport_tool(cls, tool_name: str) -> None:
-        with bpy.context.temp_override(**tool.Blender.get_viewport_context()):
+        with bpy.context.temp_override(**cls.get_viewport_context()):
             bpy.ops.wm.tool_set_by_id(name=tool_name)
 
     @classmethod
@@ -398,7 +398,7 @@ class Blender(bonsai.core.tool.Blender):
 
     @classmethod
     def update_viewport(cls) -> None:
-        tool.Blender.get_viewport_context()["area"].tag_redraw()
+        cls.get_viewport_context()["area"].tag_redraw()
 
     @classmethod
     def force_depsgraph_update(cls) -> None:
@@ -711,7 +711,7 @@ class Blender(bonsai.core.tool.Blender):
             False if enum is still invalid (as there no enum items)
             and update callback was not triggered (may need to trigger it manually).
         """
-        current_value = tool.Blender.get_enum_safe(props, prop_name)
+        current_value = cls.get_enum_safe(props, prop_name)
         if current_value is not None:
             # Value is valid, just trigger the update callback.
             setattr(props, prop_name, current_value)
@@ -958,7 +958,7 @@ class Blender(bonsai.core.tool.Blender):
     @classmethod
     def get_layer_collection(cls, collection: bpy.types.Collection) -> Union[bpy.types.LayerCollection, None]:
         project = tool.Ifc.get_object(tool.Ifc.get().by_type("IfcProject")[0])
-        project_collection = tool.Blender.get_object_bim_props(project).collection
+        project_collection = cls.get_object_bim_props(project).collection
         for layer_collection in bpy.context.view_layer.layer_collection.children:
             if layer_collection.collection == project_collection:
                 for layer_collection2 in layer_collection.children:
@@ -1564,7 +1564,7 @@ class Blender(bonsai.core.tool.Blender):
 
     @classmethod
     def get_user_data_dir(cls) -> Path:
-        props = tool.Blender.get_bim_props()
+        props = cls.get_bim_props()
         return Path(props.data_dir)
 
     @classmethod
@@ -1649,7 +1649,7 @@ class Blender(bonsai.core.tool.Blender):
     @classmethod
     def get_ifc_definition_id(cls, obj: IFC_CONNECTED_TYPE) -> int:
         if isinstance(obj, bpy.types.Object):
-            return tool.Blender.get_object_bim_props(obj).ifc_definition_id
+            return cls.get_object_bim_props(obj).ifc_definition_id
         return tool.Style.get_material_style_props(obj).ifc_definition_id
 
     @classmethod

src/bonsai/bonsai/tool/drawing.py

@@ -55,7 +55,13 @@ from typing import Optional, Union, Iterable, Any, Literal, Sequence, TYPE_CHECK
 from pathlib import Path
 
 if TYPE_CHECKING:
-    from bonsai.bim.module.drawing.prop import DocProperties, Sheet, BIMAnnotationProperties, BIMTextProperties
+    from bonsai.bim.module.drawing.prop import (
+        DocProperties,
+        Sheet,
+        BIMAnnotationProperties,
+        BIMTextProperties,
+        BIMCameraProperties,
+    )
     from bonsai.bim.module.drawing.prop import Drawing as DrawingProperties
 
 
@@ -106,6 +112,17 @@ class Drawing(bonsai.core.tool.Drawing):
     def get_text_props(cls, obj: bpy.types.Object) -> BIMTextProperties:
         return obj.BIMTextProperties
 
+    @classmethod
+    def get_camera_props(cls, camera: Union[bpy.types.Object, bpy.types.Camera]) -> BIMCameraProperties:
+        """
+        :param camera: Camera object or camera.
+        """
+        if isinstance(camera, bpy.types.Camera):
+            data = camera
+        else:
+            assert isinstance(data := camera.data, bpy.types.Camera)
+        return data.BIMCameraProperties
+
     @classmethod
     def canonicalise_class_name(cls, name: str) -> str:
         return re.sub("[^0-9a-zA-Z]+", "", name)
@@ -780,7 +797,7 @@ class Drawing(bonsai.core.tool.Drawing):
         from bonsai.bim.module.drawing.prop import get_diagram_scales
 
         # Temporarily clear the definition id to prevent prop update callbacks to IFC.
-        camera_props = camera.BIMCameraProperties
+        camera_props = tool.Drawing.get_camera_props(camera)
         update_props = camera_props.update_props
         camera_props.update_props = False
 
@@ -2199,8 +2216,8 @@ class Drawing(bonsai.core.tool.Drawing):
         return float(numerator) / float(denominator)
 
     @classmethod
-    def get_diagram_scale(cls, obj: bpy.types.Object) -> dict[str, float]:
+    def get_diagram_scale(cls, obj: bpy.types.Object) -> dict[str, str]:
-        props = obj.data.BIMCameraProperties
+        props = cls.get_camera_props(obj)
         scale = props.diagram_scale
         if scale != "CUSTOM":
             human_scale, scale = scale.split("|")

src/bonsai/bonsai/tool/loader.py

@@ -839,13 +839,14 @@ class Loader(bonsai.core.tool.Loader):
         camera = bpy.data.cameras.new(tool.Loader.get_mesh_name_from_shape(geometry))
         camera.type = camera_type
         camera.show_limits = True
+        props = tool.Drawing.get_camera_props(camera)
 
         if camera_type == "ORTHO":
             camera.clip_start = 0.002  # Technically 0, but Blender doesn't allow this, so 2mm it is!
             camera.clip_end = depth
 
-            camera.BIMCameraProperties.width = width
+            props.width = width
-            camera.BIMCameraProperties.height = height
+            props.height = height
         elif camera_type == "PERSP":
             abs_min_z = abs(min(z))
             abs_max_z = abs(max(z))
@@ -853,8 +854,8 @@ class Loader(bonsai.core.tool.Loader):
             camera.clip_end = abs_min_z
             max_res = 1000
 
-            camera.BIMCameraProperties.width = width
+            props.width = width
-            camera.BIMCameraProperties.height = height
+            props.height = height
 
             if width > height:
                 fov = 2 * atan(width / (2 * abs_min_z))

src/bonsai/bonsai/tool/search.py

@@ -51,9 +51,11 @@ class Search(bonsai.core.tool.Search):
         elif module == "diff":
             return tool.Blender.get_diff_props().filter_groups
         elif module == "drawing_include":
-            return bpy.context.scene.camera.data.BIMCameraProperties.include_filter_groups
+            assert (scene := bpy.context.scene) and (camera_obj := (scene.camera))
+            return tool.Drawing.get_camera_props(camera_obj).include_filter_groups
         elif module == "drawing_exclude":
-            return bpy.context.scene.camera.data.BIMCameraProperties.exclude_filter_groups
+            assert (scene := bpy.context.scene) and (camera_obj := (scene.camera))
+            return tool.Drawing.get_camera_props(camera_obj).exclude_filter_groups
         elif module.startswith("clash"):
             _, clash_set_index, ab, clash_source_index = module.split("_")
             props = tool.Clash.get_clash_props()

src/ifcopenshell-python/ifcopenshell/api/geometry/add_representation.py

@@ -28,6 +28,7 @@ from typing import Union, Optional, Literal, Any, TYPE_CHECKING
 from ifcopenshell.util.shape_builder import ifc_safe_vector_type, VectorType
 
 if TYPE_CHECKING:
+    import bonsai.tool as tool
     from bonsai.bim.module.geometry.helper import Helper
 
 
@@ -81,9 +82,11 @@ def add_representation(
     """
     # lazy import Helper to avoid circular import
     if "Helper" not in globals():
+        import bonsai.tool as tool
         from bonsai.bim.module.geometry.helper import Helper
 
         globals()["Helper"] = Helper
+        globals()["tool"] = tool
 
     usecase = Usecase()
     # TODO: This usecase currently depends on Blender's data model
@@ -111,7 +114,7 @@ class Usecase:
     settings: dict[str, Any]
     ifc_vertices: list[ifcopenshell.entity_instance]
     coordinate_offset: Union[npt.NDArray[np.float64], None]
-    geometry: Union[bpy.types.Mesh, bpy.types.Curve]
+    geometry: Union[bpy.types.Mesh, bpy.types.Curve, bpy.types.Camera]
     blender_object: bpy.types.Object
 
     def execute(self) -> Union[ifcopenshell.entity_instance, None]:
@@ -319,8 +322,10 @@ class Usecase:
         return self.create_mesh_representation()
 
     def create_camera_block_representation(self) -> ifcopenshell.entity_instance:
-        raster_x = self.settings["geometry"].BIMCameraProperties.raster_x
+        assert isinstance(self.geometry, bpy.types.Camera)
-        raster_y = self.settings["geometry"].BIMCameraProperties.raster_y
+        props = tool.Drawing.get_camera_props(self.geometry)
+        raster_x = props.raster_x
+        raster_y = props.raster_y
 
         if self.is_camera_landscape():
             width = self.settings["geometry"].ortho_scale
@@ -347,8 +352,10 @@ class Usecase:
         )
 
     def create_camera_pyramid_representation(self) -> ifcopenshell.entity_instance:
-        raster_x = self.settings["geometry"].BIMCameraProperties.raster_x
+        assert isinstance(self.geometry, bpy.types.Camera)
-        raster_y = self.settings["geometry"].BIMCameraProperties.raster_y
+        props = tool.Drawing.get_camera_props(self.geometry)
+        raster_x = props.raster_x
+        raster_y = props.raster_y
         fov = self.settings["geometry"].angle
 
         clip_end = self.settings["geometry"].clip_end
@@ -389,10 +396,9 @@ class Usecase:
         )
 
     def is_camera_landscape(self) -> bool:
-        return (
+        assert isinstance(self.geometry, bpy.types.Camera)
-            self.settings["geometry"].BIMCameraProperties.raster_x
+        props = tool.Drawing.get_camera_props(self.geometry)
-            > self.settings["geometry"].BIMCameraProperties.raster_y
+        return props.raster_x > props.raster_y
-        )
 
     def create_swept_disk_solid_representation(self) -> ifcopenshell.entity_instance:
         return self.file.createIfcShapeRepresentation(

src/ifcopenshell-python/ifcopenshell/util/date.py

@@ -16,6 +16,7 @@
 # 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
 import datetime
 import isodate
 from re import findall
@@ -37,7 +38,7 @@ def timedelta2duration(timedelta):
     return isodate.Duration(**components)
 
 
-def ifc2datetime(element):
+def ifc2datetime(element: Union[str, int, ifcopenshell.entity_instance]):
     if isinstance(element, str) and "P" in element[0:2]:  # IfcDuration
         duration = parse_duration(element)
         if isinstance(duration, datetime.timedelta):
@@ -246,7 +247,7 @@ def parse_duration(value: Union[str, None]) -> Union[datetime.timedelta, None]:
                 return None
 
 
-def canonicalise_time(time):
+def canonicalise_time(time: Union[datetime.datetime, None]) -> str:
     if not time:
         return "-"
     return time.strftime("%d/%m/%y")