What's the difference between `Button(onClick = {}...

# compose

[Orhan Tozan]

What's the difference between
Button(onClick = {})
and
Button(modifier = Modifier.clickable {})?
Any reason why there are two different API's for telling the button what to do on click? Which one do people generally use?

[Leland Richardson [G]]

Button is a material-vended composable, and conforms to the specifications of a material button. The modifier is a bit more low level (but not much) and is a building block that you should use if you want to make a custom button or if you want to make a different non-“button” element clickable

[Leland Richardson [G]]

Note that you could have a design system that only depends on foundation (where Modifier.clickable lives) and not on material at all.

[Orhan Tozan]

My probable thought. Makes sense, thanks. I guess the reason for Modifier to exist, is to prevent functions to have huge signatures/ large amounts of parameters?

[Leland Richardson [G]]

That is one of the benefits of modifiers, yes

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

This is an interesting question - if you passed the modifier to a material button, would that just work? Or would it confuse the button and break accessibility or something?

[Leland Richardson [G]]

i am not 100% sure but I suspect the touch events would get consumed by the modifier in the button and the “higher up” clickable modifier would end up not triggering.

[Alexandre Elias [G]]

Leland's answer is right, and also yes it would break accessibility by creating two different accessibility-focusable nodes, one for the modifier and one for the button onClick

[Alexandre Elias [G]]

Note that as of beta01, some components like Checkbox take nullable onClick so that you can disable the inner accessibility-focusable node when you're providing your own clickable modifier.

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

Would you consider adding a lint check to warn against passing a redundant clickable modifier?

[Leland Richardson [G]]

anything we can detect and have a very low false-positive rate on i think we are open to add a lint option for

[Leland Richardson [G]]

i don’t think we’ve considered this one but we probably should. willing to file a bug on it?

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

can do 👍

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

https://issuetracker.google.com/issues/181152581