For those times you want to add entrance animations in Mithril, and the adding a class/animation in `oncreate` doesn't cut it.

force-layout.js

fuction forceLayout(dom) {
  dom.getBoundingClientRect().height
}

let prm
let nodes = []
function debouncedLayout(dom) {
  if (nodes.length === 0) {
    prm = Promise.resolve(null).then(() => {
      nodes.forEach(forceLayout)
      nodes = []
    })
  }
  nodes.push(dom)
  return prm
}
const c = {
    async oncreate(v) {
        await syncLayout(v.dom)
        v.dom.classList.add('show')
    }
}

// usage: sync

const CMP = {
  view() {return m(".foo")},
  oncreate({dom}) {
    forceLayout(dom)
    dom.classList.add('show')
  }
}

// debounced

const CMP = {
  view() {return m(".foo")},
  async oncreate({dom}) {
    await debouncedLayout(dom)
    dom.classList.add('show')
  }
}