How to connect automerge's Text with UITextView?

automerge / automerge-swift-archived

Wrapper around Swift types that can be modified concurrently by different users, and merged again automatically (a CRDT).

MIT License

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How to connect automerge's Text with UITextView? #42

Closed GregOriol closed 3 years ago

GregOriol commented 3 years ago

Hi,

I'm very much interested in using automerge to sync a long text content on iOS between devices, but I'm a little bit confused between automerge's change methods (insertion of character at position, ...) and how to connect them with a UITextView: would you have any tips? Mainly, my questions are:

how to "transform" a typing inside a text view into an automerge change? is there a way I'm missing to catch character inserting/deleting within a UITextView so they can be provided into an automerge text's insert/delete methods?
how to transform back a new change received from another device while the user is editing a UITextView? It is not an option to just replace the content, how would one insert/remove characters while its content is being edited?

Best regards,

lightsprint09 commented 3 years ago

Hey,

Interesting question.

I implement text views delegate method shouldChangeTextInRange (https://developer.apple.com/documentation/uikit/uitextviewdelegate/1618630-textview)

When receiving a change I convert the given NSRange into a Swift.Range and use automerge replaceSubrange method.

lightsprint09 commented 3 years ago

I did not build a real-time editor, so I never build applying remote changes into a text view.

Is there a specific reason why you can not just replace the text views content with the new remote content?

GregOriol commented 3 years ago

Thanks for the shouldChange tip, I didn't think of this one!

Replacing content while the user is editing will break the cursor position or scroll position if the content has changed a lot, that doesn't seem very user friendly.

But, I just found another direction to look for: UITextView has a textStorage attribute, and it seems to provide access to its text content in a more detailed way.

lightsprint09 commented 3 years ago

Did a quick look into UITextView documentation.

textStorage looks promising (https://developer.apple.com/documentation/uikit/uitextview/1618611-textstorage)

lightsprint09 commented 3 years ago

Seems like we found the same solution.

If you feels confident with the solution close this issue.

GregOriol commented 3 years ago

I'll try it and reopen if needed.

Thanks!