Attempt to simplifying assigned items pointer. Stuck on read only

src/ifcblenderexport/blenderbim/bim/operator.py

@@ -4226,10 +4226,8 @@ class AddToPresentationLayer(bpy.types.Operator):
     guid: bpy.props.StringProperty()
 
     def execute(self, context):
-        presentation_layers = bpy.context.scene.BIMProperties.presentation_layers
-        new = presentation_layers[self.index]
-        new.assigned_items.items.append(self.guid)
-
+        bpy.context.active_object.BIMObjectProperties.presentation_layer = \
+        bpy.context.scene.BIMProperties.presentation_layers[self.index]
         return {"FINISHED"}
 
 
@@ -4240,11 +4238,9 @@ class AddPresentationLayer(bpy.types.Operator):
     _name = 'New Presentation Layer'
     descript = 'A Description'
     identifier = 'Something'
-    assigned_items = bpy.props.EnumProperty(items=[])
     layer_on = True
     layer_frozen = False
     layer_blocked = False
-    layer_styles = bpy.props.EnumProperty(items=[])
 
     def execute(self, context):
         new = bpy.context.scene.BIMProperties.presentation_layers.add()
@@ -4254,8 +4250,6 @@ class AddPresentationLayer(bpy.types.Operator):
         new.layer_on = self.layer_on
         new.layer_frozen = self.layer_frozen
         new.layer_blocked = self.layer_blocked
-        # new.assigned_items = self.assigned_items
-        # new.layer_styles = self.layer_styles
 
         return {"FINISHED"}
 

src/ifcblenderexport/blenderbim/bim/prop.py

@@ -779,7 +779,6 @@ class ClashSet(PropertyGroup):
 class PresentationLayer(PropertyGroup):
     name: StringProperty(name="Name")
     description: StringProperty(name="Description")
-    assigned_items: EnumProperty(items=[], name="AssignedItems")
     identifier: StringProperty(name="Identifier")
     layer_on: BoolProperty(name="LayerOn", default=True)
     layer_frozen: BoolProperty(name="LayerFrozen")

src/ifcblenderexport/blenderbim/bim/ui.py

@@ -917,8 +917,8 @@ class BIM_PT_presentation_layers(Panel):
                 ).index = props.active_presentation_layer_index
                 row = layout.row()
                 row.prop(pres_layer, "description")
-                row = layout.row()
-                row.prop(pres_layer, "assigned_items")
+                # row = layout.row()
+                # row.prop(pres_layer, "assigned_items")
                 row = layout.row()
                 row.prop(pres_layer, "identifier")
                 row = layout.row()