Osu: Files app integration for iOS import/export

[dscnnctd]

Related to #5272 and #5445
Copy to option in share UI and file location in _Files_ does not show up. _Known bug that still occurs in iOS 13._

Files app integration should be implemented to easily access beatmaps, skins, and replays manually. Game files however, should be inaccessible first before implementation.

Version: _latest release_
OS: _iOS 13_
Images:

[swoolcock]

The share UI functionality will be in the next iOS release, as it was added in this pull request: https://github.com/ppy/osu/pull/5445

The Files application is out of scope for Lazer as we do not provide “files” internally for beatmaps.

[peppy]

I think we can provide files support via an "Import" folder, which lazer reads from on next startup. May work quite well IMO.

[swoolcock]

As an iOS user I would expect that saving files implies I can copy them out again.

[peppy]

Even if the folder is called Inbox or Import?

[swoolcock]

The Files app is intended to be used for accessing the Documents directory of supported apps (in the same way that iTunes does) and for files/data that are potentially managed by a remote server or sync (DropBox etc.) which requires a separate FileProvider extension to be registered on the provisioning portal.

https://developer.apple.com/documentation/fileprovider?language=objc

"Importing" files to me implies the use of the file sharing UI (which was recently added). Lazer doesn't have the concept of files or documents so I don't think we require Files integration.

We could give it a shot and see how well it works, but it feels weird to me.

[swoolcock]

Note that I CAN see this as being useful for unsubmitted beatmaps if players want to import/export their progress from the beatmap editor, but I don't know what the end goal is for that. Not sure if there were any plans for a cloud sync or something with beatmap editing.

[peppy]

Thinking we will probably want an export folder to--

[dscnnctd]

One reason I want Files app integration is because there is no option to delete one specific skin in iOS yet. It only lets you delete all of it than just deleting only one skin.

[peppy]

File integration would not solve that due to the reasons listed above.

[dscnnctd]

So then it will be done in the app instead of doing it with integration?

[peppy]

correct. lazer uses a completely managed files solution. manually deleting any files would corrupt your database.

[dscnnctd]

All makes sense now, thanks.

[swoolcock]

Reopening for visibility if we decide to implement Files integration for import/export.