This is not ideal, but I struggled to come up with a better solution.
Background:
- The scheduler records the mtime of cards as it's building the queues,
and will throw an error in get_queued_cards() if the card on the DB
has a different mtime. This is to catch bugs - any operation that modifies
cards should be triggering a queue rebuild, or should adjust the queues
appropriately.
- The review screen skips the usual queue rebuild redraw, and directly
updates the flag icon. This is because a rebuild could cause a different
card to appear, or the answer side to switch back to the question side,
neither of which the user expects when they flag a card.
The current behaviour was broken: the queue rebuilding was still happening
on the backend, and the frontend was just failing to reflect it.
I initially tried to special-case Op::SetFlag, having it skip the queue
rebuild, and having set_card_flag() update the mtimes in the active
queue. But those mutations weren't captured by the undo log, so they
didn't get undone when undoing the set flag operation. We could perhaps
work around it by adding a separate undo entry to capture the mutation,
but it started to feel like it would be a pain to maintain moving forward.
By skipping the undo queue and retaining the same mtime, no queue
rebuild is required. Because we're setting usn, the cards will still
sync, but as mtime is not bumped, in the case of a conflict, an older
unsynced change from another client may revert the flag change.
Fixes https://forums.ankiweb.net/t/anki-2-1-50-beta-1-2/15608/145
Instead of calling a method inside the transaction body, routines
can now pass Op::SkipUndo if they wish the changes to be discarded
at the end of the transaction. The advantage of doing it this way is
that the list of changes can still be returned, allowing the sync
indicator to update immediately.
Closes#1252
Allows add-on authors to define their own label for a group of undoable
operations. For example:
def mark_and_bury(
*,
parent: QWidget,
card_id: CardId,
) -> CollectionOp[OpChanges]:
def op(col: Collection) -> OpChanges:
target = col.add_custom_undo_entry("Mark and Bury")
col.sched.bury_cards([card_id])
card = col.get_card(card_id)
col.tags.bulk_add(note_ids=[card.nid], tags="marked")
return col.merge_undo_entries(target)
return CollectionOp(parent, op)
The .add_custom_undo_entry() is for adding your own custom actions.
When extending a standard Anki action, instead store `target =
col.undo_status().last_step` after executing the standard operation.
This started out as a bigger refactor that required a separate
.commit_undoable() call to be run after each operation, instead of
having each operation return changes directly. But that proved to be
somewhat cumbersome in unit tests, and ran the risk of unexpected
behaviour if the caller invoked an operation without remembering to
finalize it.
