How to route from a modal context to a default context after an external OAuth deep link in Hotwire Native Android?

[porporpor020202]

Hello! I'm building a Hotwire Native Android app (version 1.3.1) and struggling with completing an OAuth flow initiated from a modal screen.

The Setup:

1. I have a login screen configured with context: modal in my path_configuration.json.

2. I built a custom BridgeComponent (SignInWithOauthComponent) that intercepts the "Sign in with Google" button and launches a Chrome Custom Tab.

3. After OAuth completes in the browser, my Rails server redirects back to the app via a deep link: autism://auth-callback?token=...

4. My MainActivity (launchMode="singleTask") catches the deep link in onNewIntent, extracts the token, and posts it to a LiveData.

5. The SignInWithOauthComponent (still alive in the modal) observes this token and tries to complete the login by routing to the server:
   val tokenLoginUrl = "/users/auth/token_login?token=$token"
   navigator.route(tokenLoginUrl)

The Problem:

If the login screen is set to context: default, everything works perfectly. navigator.route() successfully makes the network request.
However, if the login screen is context: modal, navigator.route() fails silently. Absolutely no network request is sent to the server.

My Questions:

What is the recommended pattern/best practice for handling an external OAuth redirect back into a modal context?

How can I reliably force the mainNavigator to route to a default URL after receiving a deep link while a modal is currently presented?

Any advice or examples would be greatly appreciated! Thank you.

[rakeshutekar]

The silent failure is expected behaviour given the contexts involved, and it comes down to what navigator.route() actually does when you cross from a modal context to a default one.

When you route() a URL, the navigator builds a NavigatorRule and picks a navigation mode from the current vs. new presentation context (Navigator.route → rule.newNavigationMode):

when (rule.newNavigationMode) {
    NavigatorMode.DISMISS_MODAL -> dismissModalContextWithResult(rule)
    NavigatorMode.TO_MODAL      -> navigateToModalContext(rule)
    NavigatorMode.IN_CONTEXT    -> navigateWithinContext(rule)
}

• From a default screen, routing to a default URL is IN_CONTEXT → it performs the visit, so the network request to token_login fires. That's your working case.
• From a modal screen, routing to a default URL is DISMISS_MODAL. And dismissModalContextWithResult does not visit the URL — it just dismisses the modal and hands a result to the screen underneath:

private fun dismissModalContextWithResult(rule: NavigatorRule) {
    navigateWhenReady {
        ...
        sendModalResult(rule)
        popModalsFromBackStack(rule)
    }
}

So no request is ever sent for token_login — the modal path expects the underlying screen to act on the result, not the modal to make the visit. On top of that, navigateWhenReady only runs once the current destination is resumed; a route() fired from your LiveData observer the instant onNewIntent returns from the Custom Tab can arrive before the modal fragment is ready, which makes it look completely silent.

Two ways to fix it

1. Simplest — make the token exchange an in-context visit. Give the completion URL the same context you're routing from (i.e. modal, or just don't mark it default) in path_configuration.json. Then the route from the modal is IN_CONTEXT, the visit actually happens, and Rails can respond however it likes — if its response redirects to a default URL (your home), that transition is the one that becomes DISMISS_MODAL and cleanly closes the modal:

{ "patterns": ["/users/auth/token_login.*"], "properties": { "context": "modal" } }

This keeps the whole flow inside the modal until the server decides you're done, which is usually what you want for an auth completion round-trip.

2. Route on the default navigator instead of the modal's. If you'd rather drive it from the deep link, don't call route() on the modal component's navigator. Handle the token at the activity, dismiss the modal, and route token_login on the default navigator — e.g. via delegate.findNavigatorHost(defaultHostId)?.navigator?.route(...) (or delegate.currentNavigator once the modal is gone). The important part is that the visit runs on a navigator whose current context is default, so it's IN_CONTEXT and the request actually fires.

I'd start with #1 — it's a one-line path-config change and sidesteps both the DISMISS_MODAL-doesn't-visit issue and the fragment-not-ready timing. Reserve #2 for when you specifically need the post-auth screen to land outside the modal stack immediately.

[porporpor020202]

Wow... thank you so much! I was struggling with this issue so much that I almost regretted choosing Hotwire Native, but thanks to you, I finally got a clue on how to solve it.
Unfortunately, I was on a very tight deadline and needed an immediate fix, so I ended up rewriting the app in pure native Android. But I still really want to master Hotwire technology in the future, and I’ll definitely give your solution a try then. Thank you so much again!
If you don't mind, could I ask for your advice on how to gain such a deep understanding of Hotwire Native? I’ve read books on Hotwire Native and thoroughly went through the official documentation, but I still couldn't figure this out on my own. It seems like your main focus is Python, so how do you gain such deep technical insights across different frameworks? You're amazingly smart!
Also, I'm really sorry for the late reply.