Advice wanted: iframe fallback to img

[vibrog]

Consider wanting to use iframes in a presentation relying on having an Internet connection, but wanting to be able to use "cached" screenshots if in an offline setting.

<iframe src="http://example.com">
  <img src="screenshot-example.com.png"/>
</iframe>

How can that be solved in a neat way?

[robflaherty]

Did you ever find a solution for this? What about adding a "offline" setting that uses JavaScript to remove the iframes wrapping your fallback content?

[vibrog]

No. My initial thought was to rely on the <object>-element's alternative/hierarchical nature.