Fun with iframes and JavaScript

Using an iframe can be pretty helpful, in certain circumstances. Sadly, it can also be a nightmarish hellscape, sometimes in the same circumstances. When an iframe has an external source, it severely restricts what can be done with it, Javascript-wise. This is particularly annoying when using an embedded form such as one from Hubspot or Podio, where they give a script to insert into the page and it generates an iframe on the fly. There are very limited ways to interact with that iframe, and there’s pretty much no ability to interact with the contents at all.

Real world example: I have an iframe form from an external site, such as one I just mentioned. It’s a lengthy form, and when it submits, it shows a “Thank you for submitting” message. The problem is, since it’s an iframe, it doesn’t refresh the container page on submission, so it remains scrolled to the bottom. I want the page to scroll back to the top.

Normally, this would be a simple click handler on the submit button, which would fire a

window.scrollTo(0,0);

or, with jQuery

$('html').scrollTop(0);

Unfortunately, click handlers don’t work with an external embedded iframe, so that won’t do. Luckily, there’s a fun hacky way to make this work. An iframe has an on('load') callback it fires, so we can hook into that. In this particular instance, we know that the first iframe load will show the form, and the second will either show errors or show a thank you message. Either way, on the second load, we want to scroll to the top.

$(document).ready(function() {
  var $iframe = $('iframe.iframe-class-name');
  $iframe.on('load', function() {
    $iframe.on('load', function() {
      window.scrollTo(0,0);
    });
  });
});

Effectively, we’re ignoring the first load, nesting the second load callback inside the first, and scrolling the window when the second one fires.

Thanks to scryptmouse for this cool trick - it saved me from pulling out any more hair in frustration.