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#compose
Title
# compose
c

codeslubber

01/30/2020, 3:04 AM
We have to put 
@Composable
on onClick lambdas now?? ugh…
r

Ryan Mentley

01/30/2020, 3:10 AM
You should not be putting 
@Composable
on onClick lambdas, what makes you say that?
they're not composable
c

codeslubber

01/30/2020, 3:11 AM
and clicking that first error goes here:
Copy code
Button(text = "Select", onClick = {
    showDialog.value = true
    })
r

Ryan Mentley

01/30/2020, 3:14 AM
Compiles just fine for me:
are you sure that the parent isn't the one missing @Composable, and it's flagging it on the Button call because that's a composable function call?
c

codeslubber

01/30/2020, 3:15 AM
it told me to make the val @Composable as well
r

Ryan Mentley

01/30/2020, 3:15 AM
can you show me the whole context?
c

codeslubber

01/30/2020, 3:19 AM
Looks like, if you put the var outside the Composable, then you get this error
I put it outside because I have a method for showing the dialog, which has to look at the same flag…
Copy code
package com.example.surveys_android

import android.app.DatePickerDialog
import android.util.Log
import androidx.compose.Composable
import androidx.compose.ambient
import androidx.compose.state
import androidx.ui.core.ContextAmbient
import androidx.ui.core.Text
import androidx.ui.foundation.shape.corner.RoundedCornerShape
import androidx.ui.layout.Column
import androidx.ui.layout.LayoutHeight
import androidx.ui.layout.Spacer
import androidx.ui.layout.Spacing
import androidx.ui.material.Button
import androidx.ui.material.surface.Card
import androidx.ui.tooling.preview.Preview
import androidx.ui.unit.dp
import java.time.LocalDate

val logTag = "DATEPICKER"

@Composable
fun DateQuestionView() {

    val showDialog  = state{
        false
    }

    val context = ambient(ContextAmbient)

    Card(shape = RoundedCornerShape(8.dp)) {
        Column(modifier = Spacing(16.dp)) {
            Text("When were you diagnosed as Prediabetic?", style = typography.h6)
            Spacer(LayoutHeight(16.dp))
            Text(LocalDate.now().toString())
            Button(text = "Select", onClick = {
                showDialog.value = true
                })
            showDatePicker()
        }
    }

}

@Composable
fun showDatePicker() {
    if (showDialog.value){
        Log.d(logTag, "inside dialog...")
        DatePickerDialog(
            context,
            DatePickerDialog.OnDateSetListener { view, year, month, day ->
                Log.d("DEBUG", "inside onDateSetListener..")
            },
            2020,
            0,
            1
        ).show()
    }
}

@Preview
@Composable
fun DateQuestionsPreview() {
    DateQuestionView()
}
this is not compiling now because I moved the flag inside the first Composable.. all other question types where it’s inside compile, where it’s outside, do not..
(needs the context as well of course, and this was working in 
dev03
)
r

Ryan Mentley

01/30/2020, 3:23 AM
that is an interesting hack with DatePickerDialog. That's not guaranteed to do what you want, since you're mixing imperative code into composition (for instance, recomposition might cause it to get executed twice). But it should mostly work.
c

codeslubber

01/30/2020, 3:24 AM
it was working fine, though I could not get NumberPicker to work in a dialog.. in the case of the latter, rewriting it with Compose is a lot less work 🙂
should I just give up on this and do a really dumb datepicker for now? (like a spinner with a bounded date range)?
r

Ryan Mentley

01/30/2020, 3:25 AM
your code looks correct to me
it looks correct to my compiler, too:
(red flag on 
now()
is an API-level check)
(I'm testing against HEAD, not dev04, but it's pretty close)
does it still throw the error when you actually compile?
c

codeslubber

01/30/2020, 3:54 AM
lemme try and move it inline
yup that does compile!
so should I consider outside vars that 2 methods use no longer supported?
(thanks, btw, I LOVE compose.. assuming when the next release makes embeddable views possible some of this will get easier…)
❤️ 1
r

Ryan Mentley

01/30/2020, 9:58 PM
No problem! I had just moved it inline as the quickest way to make it compile. outside vars that are used by multiple methods should work, but I'd have to see an exact example to understand why it's not working for you - there are some subtleties, like you can't call 
state { ... }
directly outside of composition, but you can ( think) call 
mutableStateOf(...)
c

codeslubber

01/30/2020, 10:19 PM
it was working in 03, yeah I inlined everything including repeating the typography var, but hey it works.. (that does)…
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