image_uploader.js

export default function y (elmApp) {
  var globalReader = function () {
    var reader = new FileReader()

    reader.onload = (function (event) {
      elmApp.ports.imageRead.send(event.target.result)
    })

    return reader
  }()

  elmApp.ports.readImage.subscribe(function (id) {
    var node = document.getElementById(id)
    if (node === null) {
      return
    }
    globalReader.readAsDataURL(node.files[0])
    node.value = ""
  })
}