Basic onerror handling for images

image_errors.js.es6

// Sadly, this doesn't work: img onerror events
// don't bubble, despite what the spec says:
// $(document).on('error', 'img', (e) => {

// So just do the following
// NOTE: depending on latency/loading time etc,
// there will be a FoUC, with the alt text flashing up:
$(document).on('ready page:load', () => {
  // FIXME: naïve version, hits every image:
  $('img').on('error', (e) => {
    const fallBack = `data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7`
    $(e.target).attr('src', fallBack)
  })
})