# Datum Attachment Work - In Progress

## Context
Implementing proper FreeCAD attachment for datum objects to avoid "deactivated attachment mode" warnings.
The pattern is adding `source_object` and `source_subname` parameters to each datum function and using `_setup_datum_attachment()` with appropriate MapModes.

## Completed Functions (in core.py)

### Planes
- `plane_offset_from_face` - MapMode='FlatFace'
- `plane_midplane` - MapMode='TwoFace'
- `plane_from_3_points` - MapMode='ThreePointPlane'
- `plane_normal_to_edge` - MapMode='NormalToPath'
- `plane_angled` - MapMode='FlatFace' with rotation offset
- `plane_tangent_to_cylinder` - MapMode='Tangent'

### Axes
- `axis_from_2_points` - MapMode='TwoPointLine'
- `axis_from_edge` - MapMode='ObjectXY'
- `axis_cylinder_center` - MapMode='ObjectZ'
- `axis_intersection_planes` - MapMode='TwoFace'

### Points
- `point_at_vertex` - MapMode='Vertex'

## Remaining Functions to Update (in core.py)

- `point_at_coordinates` - No attachment needed (explicit coordinates), but could use 'Translate' mode
- `point_on_edge` - Use MapMode='OnEdge' with MapPathParameter for position
- `point_center_of_face` - Use MapMode='CenterOfCurvature' or similar
- `point_center_of_circle` - Use MapMode='CenterOfCurvature'

## After core.py Updates

Update `datum_commands.py` to pass source references to the remaining point functions:
- `create_point_at_vertex` - already done
- `create_point_on_edge` - needs update
- `create_point_center_face` - needs update  
- `create_point_center_circle` - needs update

## Pattern for Updates

1. Add parameters to function signature:
   ```python
   source_object: Optional[App.DocumentObject] = None,
   source_subname: Optional[str] = None,
   ```

2. In the body section, use attachment instead of placement:
   ```python
   if source_object and source_subname:
       support = [(source_object, source_subname)]
       _setup_datum_attachment(point, support, "MapMode")
   else:
       _setup_datum_placement(point, App.Placement(...))
   ```

3. Update datum_commands.py to extract and pass source references from selection.