I gave grid (and later tried smartgrid) an ondelete parameter, but it's not getting used at all by the grid object. Inspection of the grid's Delete button shows the onclick action to be the same regardless of whether or not I have an ondelete argument to SQLFORM.grid.
Related questions, assuming the ondelete argument worked as expected: - How to pass the .id of the intended record? - How to get the signature? Could it be that part of the problem may be that my query is considered an unsupported query because it has a left join?