Hello, is there a way in Kotlin to use property delegates for data classes in constructor? I want to...

# multiplatform

[Konstantin Tskhovrebov]

Hello, is there a way in Kotlin to use property delegates for data classes in constructor?
I want to create something like Swift's Property Wrapper
https://docs.swift.org/swift-book/LanguageGuide/Properties.html#ID617

[Kris Wong]

if I understand you correctly, yes: https://kotlinlang.org/docs/reference/properties.html#getters-and-setters

[Big Chungus]

data class Entity: InterfaceOfSmth by ClassThatImplementsSomethingOfThatInterface()

[Konstantin Tskhovrebov]

@Kris Wong no. I didn't find how change getter for data class property 😢

[Big Chungus]

You can always add secondary constructor that delegates props from args

[Konstantin Tskhovrebov]

Swift's Property Wrapper changes getter's logic inside binary representation (how i understood)

[Kris Wong]

kotlin has the same concept. add a normal property to your data class and provide the getter and setter.

[Konstantin Tskhovrebov]

@Big Chungus but than i will lost all data class features (like auto toString() method)

[Big Chungus]

Nope

[Big Chungus]

You'll just do the conversion of your constructor args at instantiation. Resulting class will still be the same

[Konstantin Tskhovrebov]

No. For example:
If i use property wrapper than system log prints property via custom getter.
But data class doesn't use property delegate for generating toString() method.

[Big Chungus]

Then as @Kris Wong mentiones override getters

[Big Chungus]

This still won't break equals and toString

[Big Chungus]

Remember that every val and var have getters setters behind them

[Konstantin Tskhovrebov]

No, toString() method uses properties without getters but i want to change value before print it to log

[Konstantin Tskhovrebov]

https://www.youtube.com/watch?v=nIGlxcUES_Q▾

How I understand that Kotlin hasn't feature like Property Wrapper