Add in more migration types

[gavin-black]

Currently only a limited subset of migrations are available

[sascha]

What would be the best way to support custom migrations?

The problem that I have is that in order to determine the source model for the migration, I have to get the metadata of the current store via +[NSPersistentStoreCoordinator metadataForPersistentStoreOfType:URL:error:] but that does not support passing an options dictionary (for the passphrase). There seems to be a private method +[NSPersistentStoreCoordinator metadataForPersistentStoreOfType:URL:options:error:], but looking at it with Hopper it seems that it only calls +[NSPersistentStoreCoordinator metadataForPersistentStoreOfType:URL:error:] again.

My suggestion is to save the store's metadata outside of SQLCipher (by writing the serialized metadata to disc for instance). Do you see any security concerns in doing so?

[sedwo]

+1 for progressive migration support.

[jasper-ch-chan]

Hello @sascha,
I was wondering if you ever resolved this issue? If so, how did you go about doing so? I am also currently experiencing this problem.

[sascha]

@jasper-ch-chan: Sorry, I did not. I was able to get around using custom migrations so far and probably won't work on this again until summer. I'm happy to share my results then, but I think writing the metadata to disc is the only way that's with NSPersistentStoreCoordinator's current API.

[jasper-ch-chan]

@sascha Thanks for your response. Please keep me posted should you make any more progress in this matter. I think I'll take a stab at this implementation and see what comes of it. I'll keep you notified if you're interested.