BIM: Parse Classification in IFC correctly for conversion/type assign

src/Mod/BIM/nativeifc/ifc_objects.py

@@ -65,7 +65,7 @@ class ifc_object:
         elif prop == "Schema":
             self.edit_schema(obj, obj.Schema)
         elif prop == "Type":
-            self.Classification(obj)
+            self.assign_classification(obj)
         elif prop == "Classification":
             self.edit_classification(obj)
         elif prop == "Group":
@@ -116,6 +116,31 @@ class ifc_object:
             QtCore.QTimer.singleShot(100, obj.Document.recompute)
             QtCore.QTimer.singleShot(100, self.fit_all)
 
+    def assign_classification(self, obj):
+        """
+        Assigns Classification to an IFC object in a case where
+        the object references a Type that has a Classification property,
+        so we move copy the Type's property to our actual object.
+        """
+        
+        if not getattr(obj, "Type", None):
+            return
+
+        type_obj = obj.Type
+        if getattr(type_obj, "Classification", None):
+            # Check if there is Classification already, since user can just change
+            # the IFC type, but there could be one previously assigned which had
+            # Classification
+            if getattr(obj, "Classification", None) is None:
+                obj.addProperty("App::PropertyString", "Classification", "IFC")
+            obj.Classification = type_obj.Classification
+            obj.recompute()
+        elif getattr(obj, "Classification", None):
+            # This means user has assigned type that has no classification, so clear
+            # the one that they have currently selected
+            obj.Classification = ""
+            obj.recompute()
+
     def fit_all(self):
         """Fits the view"""
 

src/Mod/BIM/nativeifc/ifc_tools.py

@@ -48,6 +48,7 @@ try:
     import ifcopenshell.util.placement
     import ifcopenshell.util.schema
     import ifcopenshell.util.unit
+    import ifcopenshell.entity_instance
 except ImportError as e:
     import FreeCAD
     FreeCAD.Console.PrintError(
@@ -721,6 +722,37 @@ def add_properties(
                 obj.addProperty("App::PropertyString", attr, "IFC", locked=True)
             if value is not None:
                 setattr(obj, attr, str(value))
+
+            # We shortly go through the list of IFCRELASSOCIATESCLASSIFICATION members
+            # in the file to see if the newly added object should have a Classification added
+            # since we can run `add_properties`, when changing from IFC Object to IFC Type, or BIM Object (Standard Code)
+            # to BIM Type, and during the process of creation the only place where we save Classification is
+            # the file itself, so below code retrieves it and assigns it back to the newly created obj.
+            if not hasattr(obj, "Classification"):
+                assoc_classifications = ifcfile.by_type("IfcRelAssociatesClassification")
+                for assoc in assoc_classifications:
+                    related_objects = assoc.RelatedObjects
+                    if isinstance(related_objects, ifcopenshell.entity_instance):
+                        related_objects = [related_objects]
+                    if ifcentity in related_objects:
+                        cref = assoc.RelatingClassification
+                        if cref and cref.is_a("IfcClassificationReference"):
+                            classification_name = ""
+
+                            # Try to get the source classification name
+                            if hasattr(cref, "ReferencedSource") and cref.ReferencedSource:
+                                if hasattr(cref.ReferencedSource, "Name") and cref.ReferencedSource.Name:
+                                    classification_name += cref.ReferencedSource.Name + " "
+
+                            # Add the Identification if present
+                            if cref.Identification:
+                                classification_name += cref.Identification
+
+                            classification_name = classification_name.strip()
+                            if classification_name:
+                                obj.addProperty("App::PropertyString", "Classification", "IFC", locked=True)
+                                setattr(obj, "Classification", classification_name)
+                                break  # Found the relevant one, stop
     # annotation properties
     if ifcentity.is_a("IfcGridAxis"):
         axisdata = ifc_export.get_axis(ifcentity)