Hi, how can I use an abstract class in databinding...

# android

[rattleshirt]

Hi, how can I use an abstract class in databinding (3.2.0-beta02), it gives me a Could not find accessor companyName when using android:text="@{data.invoice.companyName}" (kotlin v1.2.51) with abstract var companyName: String?. In the kotlin bytecode I see a getCompanyName() method but that doesn’t work either

[arekolek]

Maybe you have data.getInvoice() that is chosen over data.invoice and doesn't have the companyName. That was the problem here https://stackoverflow.com/questions/32683129/android-databinding-error-could-not-find-accessor

[rattleshirt]

Doesn’t seem to be my case

[gildor]

You can use abstract method, sure.
Hard to see what is your problem, maybe you could to reproduce on some sampl

[rattleshirt]

but also field?

[gildor]

Databinding lib does the same what Kotlin, you can use `companyName`instead of getCompanyName()

[gildor]

maybe your problem with invoice method

[gildor]

maybe invoice type doesn’t contain companyName property

[rattleshirt]

This is what I have

abstract class InvoiceType {
    abstract var companyName: String?
}

interface AfterpayInvoice<T : InvoiceType> {
    var invoice: T
}

[rattleshirt]

with

data class Invoice(@PrimaryKey
    var orderNumber: String,
    override var companyName: String?
) : InvoiceType()

[rattleshirt]

class InvoiceWithDetails : AfterpayInvoice<Invoice> {
    @Embedded
    override lateinit var invoice: Invoice
}

[rattleshirt]

It can find the invoice

[rattleshirt]

It probably doesn’t know the type of invoice yet because of the generic

[gildor]

Yes, generic can be a problem

[rattleshirt]

It is 😞

[rattleshirt]

interface AfterpayInvoice<T : InvoiceType> {
    var invoice: T

    fun getterForInvoice() : InvoiceType
}

[rattleshirt]

this seems to work

[gildor]

You can fix it by using non-generic version of your data

[gildor]

so instead type of your ViewModel
SomeData<InvoiceType> (or how does it work)
You can use class InvoiceSomeData : SomeData<InvoiceType>

[rattleshirt]

Sorry, I don’t follow

[gildor]

It can be a problem of type check with generic on compile time and because of type erasure you cannot use model with generic, I saw something similar, so to fix this you can use ViewModel without generic param