Would it be possible to have `@Preview` working on...

# compose

[Luca Nicoletti]

Would it be possible to have @Preview working on functions with parameters all with default values? That would be great

[Luca Nicoletti]

Will do! Thanks

[Luca Nicoletti]

The error is actually generated in this file here https://android.googlesource.com/platform/tools/adt/idea/+/refs/heads/mirror-goog-studio-master-dev/compose-designer/src/com/android/tools/idea/compose/preview/Inspections.kt

[Luca Nicoletti]

at visitPreviewAnnotatedFunction : if (function.valueParameters.isNotEmpty()) {

[Luca Nicoletti]

line 101

[Andrey Kulikov]

it was discussed a bit already here: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1571861819250900?thread_ts=1571859974.243400&cid=CJLTWPH7S

[Andrey Kulikov]

some components could depend on ambients provided by the top level compoments, for example theming; so we need to wrap our component into MaterialTheme

[Luca Nicoletti]

Yeah my idea was more having it working on something like this:

Untitled

[Luca Nicoletti]

If I understood correctly, @romainguy was saying: just wrap the function with parameter in another one without parameter which provides dummy data to your parameterised one and annotate the parameter-less one with @Preview

[Andrey Kulikov]

yeah, this sounds reasonable. my idea was that there would be a lot of ui components which requires some additional configuration and probably it worth writing a separate preview fun for them where you provide everything needed, instead of trying to add @preview to your component directly

[Luca Nicoletti]

That would also work with default values as you could just go with @Preview @Composable noParams() { params() }

[Luca Nicoletti]

And that would work

[Luca Nicoletti]

Sure, that makes a lot of sense

[Luca Nicoletti]

But as you’re doing on param-less function, you can get default value for those things

[Luca Nicoletti]

and accept default params from function with them

[Andrey Kulikov]

agree

[Luca Nicoletti]

I’ll give a try on this task 😛

[Luca Nicoletti]

Will update the thread