Hi, I've got a data class but in one case I want one attribute of it to be evaluated again on each a...

# getting-started

[Bernhard]

Hi, I've got a data class but in one case I want one attribute of it to be evaluated again on each access (getting the current date basically). How do I do this?

[Michael de Kaste]

custom getter basically. However, the whole purpose of it being a data class will be null and void.

[Michael de Kaste]

data class SomeClass(
    val someField: String,
    val someOtherField: Int
) {
    val currentDate: LocalDate
        get() = LocalDate.now()
}

this is what you can do

[Bernhard]

can I decide that in the constructor without making each property a lambda?

[Bernhard]

SomeClass(currentDate by x { Date() })

[Bernhard]

basically I'd like to define the getter in the constructor

[Bernhard]

because in most cases a static value is just fine, it's just that one exception

[Bernhard]

don't want to create a separate class for that

[Michael de Kaste]

you can put the delegation in your constructor, but never specify how a field is backed in the constructor itself.

[Michael de Kaste]

Why does it NEED to be in a constructor?

[Bernhard]

because I want to configure it by case basis

[Bernhard]

usecase here is a download object where in one case I need to set the url parameter to be the current date time stamp

[Paul Griffith]

sealed class DownloadObject
data class NormalCase : DownloadObject()
class SpecialCase : DownloadObject()