Feature request: Undo management

[lucamegh]

Now that CloudKit sync is out, there's still one major feature that SQLiteData lacks compared to SwiftData: built-in undo and redo management. Have you already started exploring the idea, or are there any plans to add such a feature?

[johankool]

There is GRDBUndo as one option.

[lucamegh]

I'll have a look. Thanks

[mbrandonw]

Hi @lucamegh, this is something we will probably look at sometime in the future, but not sure when yet. Luckily it should be possible to build your own outside the library. SQLite even has a dedicated article on how undo can be implemented using triggers.

[lucamegh]

@mbrandonw Interesting. I guess special care needs to be taken when the tables are synchronized. The undo system probably shouldn’t revert changes that originate from a CloudKit sync. Is there a way to detect when DELETE, INSERT, or UPDATE operations are performed by the SyncEngine, so that I can avoid recording them?

[mbrandonw]

Yep, there's a special SQL function installed in your database connection by SQLiteData called SyncEngine. isSynchronizingChanges(). You can use that to disable triggers when an update/insert/delete is happening that originates from the sync engine rather than the user. Here's more docs.

[johankool]

Here is one seemingly working stab at adding undo/redo support to SQLiteData including taking syncing and sharing data into account: johankool#1

[rcarver]

I just finished a library for undo, will be sharing it in the next few days. It's working great in a real app, but we don't use syncing yet so that still needs testing

[rcarver]

Here's my take on undo. We just shipped it in a Mac app with TCA and it's working great.

https://github.com/latentco/sqlite-undo