Which is the best iCloud approach for my iOS notes app with text, photo, audio & drawing notes. Should I choose document storage or CloudKit?

Question

I am developing an iOS notes app where a user can add image, text, audio and drawing notes. I want to implement iCloud synchronization between multiple devices. Out of the 3 options (key value, document storage, CloudKit) which one should I choose? I would like to implement the sharing of notes (collaboration) among users as well. I am using core data as my DB currently.

Answer 1

Key-value storage is out of question due do being too limited for your goal, document storage is only recommended when you need to handle and store the document as a whole. Since you are already using CoreData for local storage, it only makes sense to use regular CloudKit with it for cloud storage and sharing.

Synchronisation of CoreData and CloudKit can be tough. I am personally using a combo of RxCoreData and RxCloudKit libraries which provide some relief in synchronisation and some syntax sugar too.

A word in advance about uniqueness constraints: for CoreData, you define them based on key(s) or hash of all values, for CloudKit it is only possible (and also required) for the CKRecord key, to the best of my knowledge. So it is best to take care of it from the very start.

Answer 2

IMHO, CloudKit is the only opinion :)

I have a note app named marknote. And at the beginning I used iCloud document storage. It worked sometime, but not stable. The worst thing is, when and whether your documents can be synced is out of your control, instead it relies on Apple's daemon service. It becomes even worse when your documents are a little big, for instance several mega bytes. So after fighting for some time, I changed to CloudKit. As @maxim-volgin has already pointed out, the implementation of CloudKit sync is tough, but it is reliable. And all headache just gone after switching to CloudKit.