This splits update_card() into separate undoable/non-undoable ops
like the change to notes in b4396b94abdeba3347d30025c5c0240d991006c9
It means that actions get a blanket 'Update Card' description - in the
future we'll probably want to either add specific actions to the backend,
or allow an enum or string to be passed in to describe the op.
Other changes:
- card.flush() can no longer be used to add new cards. Card creation
is only supposed to be done in response to changes in a note's fields,
and this functionality was only exposed because the card generation
hadn't been migrated to the backend at that point. As far as I'm aware,
only Arthur's "copy notes" add-on used this functionality, and that should
be an easy fix - when the new note is added, the associated cards will
be generated, and they can then be retrieved with note.cards()
- tidy ups/PEP8
- note.flush() behaves like before, as otherwise actions or add-ons
that perform bulk flushing would end up creating an undo entry for
each note
- added col.update_note() to opt in to the new behaviour
- tidy up the names of some related routines
- transact() now automatically clears card queues unless an op
opts-out (and currently only AnswerCard does). This means there's no
risk of forgetting to clear the queues in an operation, or when undoing/
redoing
- CollectionOp->UndoableOp
- clear queues when redoing "answer card", instead of clearing redo
when clearing queues
