Fix missing IFC descriptions for already added pset props

Example - https://files.catbox.moe/dg1mzk.png

src/bonsai/bonsai/bim/helper.py

@@ -296,7 +296,13 @@ def add_attribute_enum_items_descriptions(
         new_enum_description.name = description
 
 
-def add_attribute_description(attribute_blender: bonsai.bim.prop.Attribute, attribute_ifc=None):
+def add_attribute_description(
+    attribute_blender: bonsai.bim.prop.Attribute,
+    attribute_ifc: Union[ifcopenshell.entity_instance, None] = None,
+) -> None:
+    """
+    :param attribute_ifc: IFC Entity to use as a fallback source of description (using "Description" attribute).
+    """
     if not attribute_blender.name:
         return
     version = tool.Ifc.get_schema()

src/bonsai/bonsai/core/pset.py

@@ -87,7 +87,7 @@ def enable_pset_editing(
         has_template = False
 
     if pset:
-        pset_tool.import_pset_from_existing(pset, props)
+        pset_tool.import_pset_from_existing(pset, props, pset_template)
         pset_tool.set_active_pset(props, pset, has_template)
     else:
         pset_tool.enable_proposed_pset(props, pset_name, pset_type, has_template)

src/bonsai/bonsai/tool/pset.py

@@ -30,6 +30,7 @@ from typing import Union, Literal, Any, TYPE_CHECKING, assert_never
 
 
 if TYPE_CHECKING:
+    from bonsai.bim.prop import Attribute
     from bonsai.bim.module.pset.prop import (
         PsetProperties,
         GlobalPsetProperties,
@@ -171,8 +172,16 @@ class Pset(bonsai.core.tool.Pset):
         return special_type
 
     @classmethod
-    def import_pset_from_existing(cls, pset: ifcopenshell.entity_instance, props: PsetProperties) -> None:
+    def import_pset_from_existing(
-        pset_props = []
+        cls,
+        pset: ifcopenshell.entity_instance,
+        props: PsetProperties,
+        pset_template: Union[ifcopenshell.entity_instance, None],
+    ) -> None:
+        """
+        :param pset_template: Pset Template to use as a source for descriptions.
+        """
+        pset_props: tuple[ifcopenshell.entity_instance, ...] = ()
         if pset.is_a("IfcElementQuantity"):
             pset_props = pset.Quantities
         elif pset.is_a("IfcPropertySet"):
@@ -180,6 +189,16 @@ class Pset(bonsai.core.tool.Pset):
         elif pset.is_a("IfcMaterialProperties") or pset.is_a("IfcProfileProperties"):
             pset_props = pset.Properties
 
+        prop_templates: dict[str, ifcopenshell.entity_instance] = {}
+        if pset_template:
+            prop_templates = {prop.Name: prop for prop in pset_template.HasPropertyTemplates}
+
+        def process_prop_description(metadata: Attribute) -> None:
+            prop_name = metadata.name
+            if prop_name not in prop_templates:
+                return
+            bonsai.bim.helper.add_attribute_description(metadata, prop_templates[prop_name])
+
         for prop in sorted(pset_props, key=lambda p: p.Name):
             if props.properties.get(prop.Name):
                 continue  # This property has already been added from a template
@@ -230,6 +249,7 @@ class Pset(bonsai.core.tool.Pset):
                 metadata.is_optional = True
                 metadata.special_type = cls.get_special_type_for_prop(prop)
                 metadata.set_value(metadata.get_value_default() if metadata.is_null else value)
+                process_prop_description(metadata)
 
     @classmethod
     def get_prop_template_primitive_type(cls, prop_template: ifcopenshell.entity_instance) -> str:
@@ -333,7 +353,7 @@ class Pset(bonsai.core.tool.Pset):
 
         # For every prop we first ensure that existing prop value type matches the template value type
         # to prevent data loss and error casting data.
-        # Property will be added later by import_pset_from_existing.
+        # Existing property will be added later by import_pset_from_existing.
         for prop_template in sorted(pset_template.HasPropertyTemplates, key=lambda p: p.Name):
             if (
                 not prop_template.is_a("IfcSimplePropertyTemplate")