MongoDB: raise 404 in get_one

[neithere]

Given

slot = Slot.get_one(db, {'_id': ObjectId(slot_id)})
if not slot:
    abort(404)
return render_template('foo.html', slot=slot)

Desired

slot = Slot.get_one(db, {'_id': ObjectId(slot_id)})    # if not found, `abort(404)` is called
return render_template('foo.html', slot=slot)

This implies one of these options:

1. a backwards-incompatible change of behaviour + dependency on a certain web framework
2. a mechanism to customize the behaviour (on app level?) by (re)defining the exception factory (e.g. NotFound / lambda: abort(404) / None).

The second option is of course much better.