Equivalent to react's setState callback?

I have a need to execute arbitrary logic only after a state change has been applied. In react land, I can accomplish this by running setState(state, cb). Based on my extremely limited hyperapp experience, this appears to be impossible since, in order to update state, an action must return.

Is there already a means of doing what I want in hyperapp? If not, is there any interest in adding this feature?

[zaceno]

@jpodwys FWIW: I sometimes make a generic reduce action, to use, for example as a callback in promises.

actions = {
  reduce: fn => s => fn(s),
  myAction: x => (state, actions) => {
    doSomethingAsync(state.foo).then(result => actions.reduce(state => {
      //now I have the current state after the update 
    }))
  }
}

… it’s along the lines of your setState action, but without the actual state-setting part 😉 It suffers from the same problem though: you have to repeat it in every namespace where you’ll need it, if you’re using nested actions. But since it’s not a very common need, and the action is so small, it’s no big deal.

[jpodwys]

It’s not a bad idea, but you will lose access to it once you start using nested actions.

Oh right, I’m not using nested state/actions so I hadn’t considered this. Good catch. Your solution makes sense, I’ll give it a go!