Hello, how can i use the `renderProperty`, to chan...

# doodle

[Cherrio LLC]

Hello, how can i use the renderProperty, to change the value of textField? When I try, I get:

[Nick]

Hey. I’m not at a computer to check, but I think the issue is the property needs to be a member of a View class. You’re defining this as a local member. Try moving the declaration out of init:

val view = object: View() {
    var time by renderProperty(initial: "")

    init {
    }
}

[Nick]

Also, renderProperty will trigger a rerender of the View it belongs to whenever that property is changed. So you only need it if you want to repaint the view. Otherwise you can use an observable instead. It fires whenever the property changes.

val view = object: View() {
    var time by observable(initial: "") { old, new ->
    }

    init {
    }
}

[Nick]

Also, observable doesn’t have to be a property of a View. So it’s more flexible.

[Cherrio LLC]

So how does it know when to rerender?

[Nick]

renderProperty is just an observable that calls rerender whenever it is changed. it then calls the block you pass to it to let you do more stuff. observable calls it’s callback whenever you set a new value that isn’t equal to the current one.

So renderProperty is like doing:

object: View() {
    var property by observable(initial) { old,new ->
        rerender()
        …
    }
}

This works because observable will call the block whenever property is changed