How can I call a function just once even if there’s configuration changes?

# compose

[Tgo1014]

How can I call a function just once even if there’s configuration changes?

[Colton Idle]

By function, do you mean composable? If so, just don't change the backing state?

[Tgo1014]

I want that when the composable shows it calls a fetch() in the view model, but just the first time

[Suser]

you might be after disposable effect

[jannis]

Don't trigger the fetch logic from the UI layer, e.g. in your init method of your ViewModel

[Tgo1014]

Hmm I guess makes sense, I’m having some issues on testing because sometimes the initial state is not working properly, so that’s why I was thinking about removing the init{} from it, so I guess ideally I should fix it 😅

[Adam Powell]

+1 to the idea that this policy is probably better implemented at the ViewModel layer or your data layer that the ViewModel provides access to

[Casey Brooks]

Ideally, the function itself shouldn't care about the logic at all. The VM produces some state, and you pass that state into the Composable function. Testing should be just trivially re-creating that state object and passing it in without the VM

[Tgo1014]

I guess the problem is some racing condition that I can’t find, it sometimes work and sometimes doesn’t so I’m going crazy to understand, but that’s not related to compose 😅

[josefdolezal]

there was a really good thread about this issue exactly.. the problem with vm’s init is that it’s actually not connected to composable’s lifecycle. my preference is to use flows instead

[Tgo1014]

Thanks for the link @josefdolezal! I’ll take a look 🙂