feat: External Link Native Module

[jimhunty]

Why are you doing this?

With the release of iOS16, and with our progression towards Reader App status, this module hopes to expose the Native External Link module for iOS. A noop is created for Android to give parity between the platforms

Changes

• Android native module added with zero functionality
• iOS Native module added with an attempt to access External Link
• TS function added to expose these modules

Please note: This is untested in iOS due to the inability to build (Ophan issue). However, it builds and works as expected for Android.

Screenshots

[groakland]

LGTM

[ddramowicz]

Added a couple ideas around how to get Swift async/await to work with RN.
The other option could be to open the modal completely natively, that way you wouldn't need to ever wait for a callback from the native layer before opening the modal from RN.
The RN layer would call a nativeopen function of some kind, and it would do all the logic in there, e.g.

  @objc
    func open() {
        guard #available(iOS 16.0, *) else { return }
        Task {
            let canOpen = await ExternalLinkAccount.canOpen
            let canMakePayments = SKPaymentQueue.canMakePayments()

            if canOpen, canMakePayments {
               try await ExternalLinkAccount.open()
            }
        }
    }

Even nicer would be to make this call throwing so we could pass back any failures to the RN layer (if RN knows how to handle throwing methods, I don't know!)

[ddramowicz]

I don't think this result is being passed back or stored anywhere?

[ddramowicz]

you also don't need to try here as canOpen is not a throwing function

[ddramowicz]

Well, the above comments are more FYI rather than something that will actually help with your problem of interfacing React Native with Swift's Async/Await. I found this SO post which suggested using events (https://stackoverflow.com/questions/72302077/react-native-module-in-swift-with-async-function-throws-is-not-a-recognized-obje), would that be an option, do you think? Something like this:

  @objc
    func canOpen() {
        guard #available(iOS 16.0, *) else { return }
        Task {
            let result = await ExternalLinkAccount.canOpen
            sendEvent(withName: "OpenEvent", body: result)
        }
    }

I'm not sure how you'd get the React layer to await the result from the event, but maybe this is an option? It sounds like Swift async functions don't work in React Native, which is a shame as many new iOS APIs are Swift-only and often use async/await...

[jimhunty]

Thanks for your feedback @ddramowicz, thats all very helpful. I have gone with the simpler solution suggested. The only downside is the RN layer not knowing when it fails, but this should be edge case and something we can look to improve in future.

[ddramowicz]

Nice! Looks good, but we should probably hold off on merging until we can test it - we'll need that entitlement as well for this to work as expected.

[jimhunty]

Waiting on legal sign off.