If I want my composable to take in a list of other...

# compose

[Colton Idle]

If I want my composable to take in a list of other composables. For example, I want to take in a list of buttons, and depending on the state of my composable, I will show one of the buttons via buttonList[selected]()

I thought defining an argument into my composable like this would work

buttonList: List<@Composable ColumnScope.() -> Unit> but then sending in a listOf(CustomButton(), CustomButton2()) doesn't actually work. Thoughts?

[Zach Klippenstein (he/him) [MOD]]

Because the value of the expression CustomButton() isn’t the custom button function, it is the return value of CustomButton. You need to either pass a function reference or a lambda.

[Colton Idle]

@Zach Klippenstein (he/him) [MOD] thanks!

If I understand correctly, I would pass in this?

listOf(() -> CustomButton(), () -> CustomButton2())

[Zach Klippenstein (he/him) [MOD]]

That’s not valid kotlin syntax, I think those are Java lambdas? But it’s the right idea, yea

[Colton Idle]

TIL that idk what lambdas are in kotlin. lol Thanks I'll search it up from here

[Adam Powell]

Just stick some {} around the calls

[Colton Idle]

Oh jeez. listOf({CustomButton()}, {CustomButton2()}) worked. I never really felt comfy with lambdas and functions and stuff and it bit me here.

Appreciate the hand holding. Gotta re-read the Big nerd ranch kotlin book on my desk. 🙃

[Timo Drick]

Is there any plan to support function references for composable functions in the future?
Because this would be the preferred way of doing this.

[Adam Powell]

iirc there was a kotlinc extension point that the compose plugin would need to handle function references to composable functions that isn't present today. Once that's available we'll add support, but the workaround of using a lambda is simple enough that we haven't considered it a high priority, just a nice to have for completeness