I need to pass a complex object via navigation. Th...

# compose

[ursus]

I need to pass a complex object via navigation. The type lives in a pure kotlin module, so no android.

Would you rather create a private wrapper that is Parcelable or, serialize it via Json or Protobuf
Btw I meaasured the protobuf and it still sometimes takes 2ms to serialize (measured in debug mind you)

TLDR; is it unreasonable for passing arguments to take 2ms in runtime, or should I rather sacrifice developer time and write the silly wrapper?

[agrosner]

Hoist it into a higher lived object like activity level or app level. When you “need” to pass large objects like that , it’s a code smell.

[ursus]

why would it be a code smell? its not large, couple of fields, basic struct

[agrosner]

The word “complex”

[ursus]

as opposed to primitive

[agrosner]

Serializing it to a single field could easily by done by doubly encoding it key + value as a single parameter value

[agrosner]

Just in case you got values that have spaces or special characters, assuming you mean jetpack navigation

[ursus]

you mean like this?

bundle.putString(.., struct.foo)
bundle.putString(.., struct.bar)

[agrosner]

Compose navigation? Or android navigation

[ursus]

well, both really, I though compose nav could take a bundle as well .. is it only a string?

[agrosner]

Jetpack navigation compose only takes url arguments

[agrosner]

Pretty sure

[ursus]

I see, so even lamer

do people really destructure it to n query params manually? that seems so backwards tbh

[ursus]

coming from ios, I only want to pass this struct to a screen, thats it .. its not backed by database or any other reactive store, simply a tuple of n values

[agrosner]

It’s not bad to write a library to do it. https://github.com/raamcosta/compose-destinations

We at my company I’ve written a library that’s type safe too using ksp

[ursus]

think parsed from a deeplink

[Stylianos Gakis]

If you want to keep your sanity, just use this https://github.com/kiwicom/navigation-compose-typed and you can pass the object as-is, as long as it is @Serializable

[agrosner]

You might enjoy compose destinations

[Stylianos Gakis]

And if you notice this https://issuetracker.google.com/issues/188693139 you will see that the official library is building their type-safe tooling exactly around kotlinx.serialization as well. So the migration to the official solution will be painless

[ursus]

I see, but that does what, serialize it to json synchronously on main thread?

[ursus]

I mean I could do that myself, I was just curious about perf impliciations

[ursus]

since 2ms ... idk, that seems like a lot.. on a 120Hz screen you have what, 8ms to do everything?

[Stylianos Gakis]

It will do this https://github.com/kiwicom/navigation-compose-typed/blob/f4e8ebea7e52216c4a431eb0c[…]ain/kotlin/com/kiwi/navigationcompose/typed/internal/Routing.kt

And the official library is doing more or less the same too it seems, on the main thread.
1:https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:navigati[…]roller.navigate&ss=androidx%2Fplatform%2Fframeworks%2Fsupport
2:https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:navigati[…]gation-runtime%2Fsrc%2Fmain%2Fjava%2Fandroidx%2Fnavigation%2F
3:https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:navigati[…]teRouteWithArgs&ss=androidx%2Fplatform%2Fframeworks%2Fsupport
4:https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:navigati[…]n/java/androidx/navigation/serialization/RouteEncoder.kt;l=35

[ursus]

right .. so I guess it's fine?

I mean it does fall down to 0-1, probably some caching of the serializer happening etc

[Stylianos Gakis]

Yeah, if you are worried try to profile your app to see how fast this happens. I doubt it’s a problem, especially serializing a class with 2 objects as you say

[ursus]

what time would you consider not fine?

[ursus]

anyways good to know they're going this way anyways, thank you!

[Stylianos Gakis]

what time would you consider not fine?

The time which makes my app miss frames 😄

anyways good to know they’re going this way anyways, thank you!

Yeah unless I am missing something it seems like they indeed are doing this too

[Zoltan Demant]

You can also consider instead passing a key/id of the complex object, then retrieving it from some form of cache 🙂

[ursus]

sure if you have it, I mean for the times when you don't have a store