setState typing problem about haxe-react

[dpeek]

You need to define your state typedef with all fields optional:

typedef MyState = {
    @:optional var enabled:Bool;
    @:optional var focused:Bool;
}

We can look into some kind of macro utility to help here but unfortunately there are no build macros on typedefs.

[zabojad]

You could perhaps also make some kind of factory method that initializes a state object with default values, to avoid having to set all the fields as optional (and that could probably be a macro)... Also, I do prefer this syntax:

typedef MyState = {
    ? enabled : Bool,
    ? focused : Bool
}

[dpeek]

When we call setState we don't want to pass default values for anything that isn't provided, this needs to be compile time somehow. I'll look into it.

As for syntax, that's entirely up to you :)

[kevinresol]

@dpeek your optional fields solution is what I mentioned in workaround no.2
That isn't really perfect because we may actually want to specify some fields as mandatory.

I am not sure if @:genericBuild can help here, to generate a concrete TStateAllOptional type for each generic type TState, and use that in the setState function. But that would create a lot of concrete generic types of ReactComponent, which is not really necessary in the js target.

[kevinresol]

Not much can be done on this.