Web: Attach navigation to the browser history

[iruizmar]

Hey!

In a web app, the user should be able to reach any screen by using the URL. Also, the url of the browser should be changing depending on the current screen.

Is there anyway to model this with Circuit? I guess the topic is closely related to deep linking.

For instance, Decompose is handling this with its WebHistoryController.

[ZacSweers]

Web is a fairly under-tested platform for us as we don't use it inside of Slack at the moment. I'm not super familiar with how Kotlin/JS apps can update the url, but based on the example you linked I think it should be fairly straightforward to observe the current back stack (which is stable).

For deeplinking, we have a very primitive example in the STAR sample. A more built out implementation that uses annotations to denote deeplinkable targets and using DI can be seen here: ZacSweers/CatchUp#880. It more or less boils down to being able to decompose a given URL into a list of screens that you can push onto the back stack.

[iruizmar]

Can you elaborate on how to observe the backstack? I tried to experiment in that direction and I couldn't find anything, at least on the public API, that allowed me to observe changes either on Navigator nor Backstack.

Thanks for the deep link sample, I'll take a look. I think both topics are connected.

[ZacSweers]

Take a look at the implementation of NavigableCircuitContent. Ultimately it's observing the back stack and just showing the top record

[iruizmar]

I've been trying to implement a first draft of this in my project but it's more complicated than I thought:

1. How should it handle nested navigation?
2. Navigation in the browser can move several screens at once (because the user might navigate using the history). How would the backstack be updated accordingly?
3. There should be a map between screen/record and url (which may contain path parameters). Where should this be placed? Should it be passed by the user?

And everything is related to deep links, actually. A url can be translated to a list of screens that should be pushed into the navigator immediately.

So here are my questions:

1. Are there plans to add support for deep linking in the library itself?
2. What about the specific case of attaching them to the browser history?
3. If not, would you want me to contribute this into the library? Being honest, I would need strong guidance from you.

[ZacSweers]

To be honest, this is all very vague and hard to answer 😅. We are also fairly out of our depth with web APIs in KMP. I would recommend prototyping on your own and, if you have something you think is worth contributing back later, we can take a look at it then.