imis_shim.js

var smartFormsStaticPrefix = '/_smart_forms/static',
    smartFormsApiPrefix = '/_smart_forms/api'

function smartFormsInit() {
  var req = new XMLHttpRequest()

  function transformElementUrls(el) {
    var href = el.getAttribute('href'),
        src = el.getAttribute('src')
    if (href !== null) el.setAttribute('href', smartFormsStaticPrefix + '/' + href)
    if (src !== null) el.setAttribute('src', smartFormsStaticPrefix + '/' + src)
  }

  req.onreadystatechange = function() {
    var i, dom, container, containerFirst, newEl, stylesheets, scripts, overlays, others

    if (req.readyState !== XMLHttpRequest.DONE) return
    if (req.status !== 200) alert('An error occurred')

    dom = new DOMParser().parseFromString(req.responseText, 'text/html')
    stylesheets = dom.querySelectorAll('link[rel="stylesheet"]')
    scripts = dom.querySelectorAll('script')
    overlays = dom.querySelectorAll('body > .overlay')
    others = dom.querySelectorAll('body > *')

    container = document.getElementsByTagName('head')[0]
    for (i = 0; i < stylesheets.length; i++) {
      transformElementUrls(stylesheets[i])
      container.appendChild(stylesheets[i])
    }
    for (i = 0; i < scripts.length; i++) {
      transformElementUrls(scripts[i])
      newEl = document.createElement('script')
      newEl.setAttribute('src', scripts[i].getAttribute('src'))
      newEl.innerText = scripts[i].innerText
      container.appendChild(newEl)
    }
    container = document.getElementsByTagName('body')[0]
    containerFirst = container.firstChild
    for (i = 0; i < overlays.length; i++) {
      transformElementUrls(overlays[i])
      containerFirst.parentElement.insertBefore(overlays[i], containerFirst)
    }
    container = document.getElementById('smart-forms-content-marker')
    for (i = 0; i < others.length; i++) {
      if (others[i].classList.contains('overlay')) continue
      if (others[i].tagName.toUpperCase() === 'SCRIPT') continue
      transformElementUrls(others[i])
      container.parentElement.insertBefore(others[i], container)
    }
  }
  req.open('GET', smartFormsStaticPrefix + '/index.html', true)
  req.send()
}
smartFormsInit()