feat: add a new example for oauth that uses webview

[totzk9]

This PR provides an example using webview.

The previous example wont work because OAuth providers like Google, Facebook and Apple doesn't acknowledge launchUrl as secure enough (It does work for flutter_web tho).

[totzk9]

This should provide another solution for #93

[dbarrosop]

Nice, thanks. Will ask a colleague to review in the upcoming days. For the record, we are currently working on adding support for native authentication with hasura-auth so there will be no need of using a webview for apple/google sign in on ios/android.

[onehassan]

Thank you @totzk9 for your contribution! 🙌

I encountered an issue while trying to run this on an iOS simulator. It seems there might be a problem with the url_launcher dependency.

Here’s the error I get:

/.pub-cache/hosted/pub.dev/url_launcher_ios-6.2.4/ios/Classes/Launcher.swift:20:1: error: type 'UIApplication' does not conform to protocol 'Launcher'
    extension UIApplication: Launcher {}

[totzk9]

I think we can close this PR since Nhost now supports idTokens for OAuth

[dbarrosop]

Don't you need the webview for, let's say "Sign in with Apple" on android or "sign in with Google" on iOS"? Assuming you want to provide parity between iOS/Android applications.

[totzk9]

That does makes sense.
I was only looking on my use case and didn't thought of others - I also noticed some apps that uses webviews for auth (mostly mobile games).

Let me look on the issue mentioned above.

PS. Theres a plugin for iOS that can call native oauth for Google.
PPS. using webview for Sign in with Apple will still call the native dialog and still retain its form (cool move by Apple 😉)