Some iframes work out-of-the-box, others need a bit of attention
When you create an annotation, Cord takes a screenshot of the document and stores it alongside the annotation.
If the document contains iframes, things can get interesting:
src attribute is from the same origin as the document, then Cord will correctly capture the contents of that
<iframe> in the screenshot, with no special tweaks needed from the developer
src attribute is from a different origin than the document, and you can change the HTML inside the
<iframe>, then a script tag must be added to the HTML of the
<iframe> document. This script will set the necessary security settings in the page necessary to enable a parent window to capture a screenshot of its contents.
<!-- this script allows the Cord SDK to communicate with this iframe when taking screenshots -->
src attribute is from a different origin than the document, and the
<iframe> content is outside the control of the developer, then the area of the
<iframe> will be replaced with a "Content not available" placeholder in the screenshot