append_asset to support IfcPresentationLayerAssignment #6023

src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py

@@ -256,7 +256,8 @@ class Usecase:
         self.whitelisted_inverse_attributes = {
             "IfcObjectDefinition": ["HasAssociations"],
             self.base_material_class: ["HasExternalReferences", "HasProperties", "HasRepresentation"],
-            "IfcRepresentationItem": ["StyledByItem"],
+            "IfcRepresentationItem": ["StyledByItem", "LayerAssignment"],
+            "IfcRepresentation": ["LayerAssignments"],
         }
         self.existing_contexts = self.file.by_type("IfcGeometricRepresentationContext")
         element = self.add_element(self.settings["element"])
@@ -269,7 +270,11 @@ class Usecase:
             "IfcObject": ["IsDefinedBy.IfcRelDefinesByProperties"],
             "IfcElement": ["HasOpenings"],
             self.base_material_class: ["HasExternalReferences", "HasProperties", "HasRepresentation"],
-            "IfcRepresentationItem": ["StyledByItem"],
+            "IfcRepresentationItem": [
+                "StyledByItem",
+                "LayerAssignments" if self.file.schema == "IFC2X3" else "LayerAssignment",
+            ],
+            "IfcRepresentation": ["LayerAssignments"],
         }
         self.existing_contexts = self.file.by_type("IfcGeometricRepresentationContext")
         element = self.add_element(self.settings["element"])
@@ -362,6 +367,13 @@ class Usecase:
         # relationships that can reference many other assets that we are not
         # interested in.
 
+        # For layer assignment we don't want to add it's items
+        # to avoid adding representations / items that are not related to current append_asset.
+        skip_not_reused_entities_attr_i = None
+        if element.is_a("IfcPresentationLayerAssignment"):
+            # 3 IfcPresentationLayerAssignment.AssignedItems
+            skip_not_reused_entities_attr_i = 2
+
         element_identity = element.wrapped_data.identity()
 
         # Check if inverse element was created before.
@@ -386,8 +398,15 @@ class Usecase:
             elif isinstance(attribute, tuple) and attribute and isinstance(attribute[0], ifcopenshell.entity_instance):
                 new_attribute = []
                 for item in attribute:
-                    if not self.is_another_asset(item):
+                    if self.is_another_asset(item):
-                        new_attribute.append(self.add_element(item))
+                        continue
+                    if skip_not_reused_entities_attr_i is not None and i == skip_not_reused_entities_attr_i:
+                        identity = item.wrapped_data.identity()
+                        if (item := self.reuse_identities.get(identity)) is None:
+                            continue
+                    else:
+                        item = self.add_element(item)
+                    new_attribute.append(item)
                 # If rel exists we need to make sure previously assigned elements are untouched
                 # e.g. not to assign a material or a pset from element.
                 if existing_rel:

src/ifcopenshell-python/test/api/project/test_append_asset.py

@@ -17,6 +17,7 @@
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
 import test.bootstrap
+import ifcopenshell.api.layer
 import ifcopenshell.api.geometry
 import ifcopenshell.api.georeference
 import ifcopenshell.api.pset
@@ -527,6 +528,40 @@ class TestAppendAssetIFC2X3(test.bootstrap.IFC2X3):
             == 0.01
         )
 
+    def test_append_presentation_layer_for_representation_item(self):
+        library = ifcopenshell.api.project.create_file(version=self.file.schema)
+        ifcopenshell.api.root.create_entity(library, ifc_class="IfcProject")
+        element = ifcopenshell.api.root.create_entity(library, ifc_class="IfcWall")
+        builder = ShapeBuilder(library)
+        model = ifcopenshell.api.context.add_context(library, context_type="Model")
+        item = builder.extrude(builder.profile(builder.rectangle((1, 1))))
+        representation = builder.get_representation(model, item)
+        ifcopenshell.api.geometry.assign_representation(library, element, representation)
+        layer = ifcopenshell.api.layer.add_layer(library, name="TestLayer")
+        ifcopenshell.api.layer.assign_layer(library, items=[item], layer=layer)
+
+        ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcProject")
+        ifcopenshell.api.project.append_asset(self.file, library=library, element=element)
+        extrusions = tuple(self.file.by_type("IfcExtrudedAreaSolid"))
+        assert self.file.by_type("IfcPresentationLayerAssignment")[0].AssignedItems == extrusions
+
+    def test_append_presentation_layer_for_representation(self):
+        library = ifcopenshell.api.project.create_file(version=self.file.schema)
+        ifcopenshell.api.root.create_entity(library, ifc_class="IfcProject")
+        element = ifcopenshell.api.root.create_entity(library, ifc_class="IfcWall")
+        builder = ShapeBuilder(library)
+        model = ifcopenshell.api.context.add_context(library, context_type="Model")
+        item = builder.extrude(builder.profile(builder.rectangle((1, 1))))
+        representation = builder.get_representation(model, item)
+        ifcopenshell.api.geometry.assign_representation(library, element, representation)
+        layer = ifcopenshell.api.layer.add_layer(library, name="TestLayer")
+        ifcopenshell.api.layer.assign_layer(library, items=[representation], layer=layer)
+
+        ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcProject")
+        ifcopenshell.api.project.append_asset(self.file, library=library, element=element)
+        representations = tuple(self.file.by_type("IfcRepresentation"))
+        assert self.file.by_type("IfcPresentationLayerAssignment")[0].AssignedItems == representations
+
 
 class TestAppendAssetIFC4(test.bootstrap.IFC4, TestAppendAssetIFC2X3):
     # NOTE: breaks in IFC2X3 since IfcProfileDef doesn't have "HasProperties" inverse in ifc2x3