Hi How can we share ViewModel across platforms in compose Mu

Question

Hi How can we share ViewModel across platforms in compose Multiplatform

Alejandro Rios · Answer

This could be an option <https medium com daniel atitienei how to implement flows and share viewmodels in kotlin multiplatform mobile kmm 89dfe08758ef>

Pablichjenkov · Answer

Compose multiplatform is one single code base place all compose viewmodel stuff in commonMain

Ahmad Hassan · Answer

< Pablichjenkov> As you know ViewModel is a special class that survives across configuration changes So one solution is expect actual Is there any other solution

Ahmad Hassan · Answer

< amezcua> Other than expect actual approach

Alejandro Rios · Answer

Looking in the history I ve found <https kotlinlang slack com archives C3PQML5NU p1673949296610909|this>

Alejandro Rios · Answer

BTW I m not ` amezcua` sweat smile

Ahmad Hassan · Answer

I just saw the first name sweat smile

Pablichjenkov · Answer

That VM behavior is only on Android There are a couple of libraries that mimic the behavior to other platforms but in my opinion is a waste of energy because those platforms never had interest in process death recover or they don t suffer from things like Activity death on device rotation

Pablichjenkov · Answer

If you ask me I would say Android is the wrong platform here

Pablichjenkov · Answer

A lot of ceremony for a problem that can should be avoided by simply handling configuration changes at the code level not killing the Activity

Pablichjenkov · Answer

Anyways Decompose I believe ported this behavior to the other lands Voyager did it too but I believe they don t support iOS haven t checked their repo in a while There might be some other project on GitHub doing that do a lookup there

ayodele · Answer

If you want to have the android viewmodel in common code just expect actual a class that androidMain actuals it extend it by ViewModel from androidx Then you can make your other viewmodels in common extend the expected viewmodel I dunno if you understand

Pablichjenkov · Answer

But he still needs to install it s VMs in a lifecycleowner Meaning you will have to use Navigation Component or Fragments Activity in Android Then the code will get a bit fragmented between platforms I think that approach fits better a KMM app but if you plan to go compose multiplatform better use the libraries I mentioned above or not using Android Viewmodel concept at all just use compose State

ayodele · Answer

Oh compose multiplatform Didn t spot that < Pablichjenkov> you re right