Re: Comments on HTML5 Image Description Extension (longdesc)

On Aug 25, 2014, at 6:16 AM, chaals@yandex-team.ru wrote:

> It doesn't convey the requirement that users of magnification software who can use a mouse can access the description (one group of users excluded by James Craig's "iframe" technique), nor various other situations.

Charles,

You're misrepresenting that example. Nothing about the iframe technique excludes this set of users.

You may have missed this text in the example; it was first posted in September 2012: "The iframe approach is also more in line with universal design principles in that it could be scripted to show the alternative frame contents to sighted users upon request, without the need for assistive technology."

To connect the dots, I spent a few minutes this morning updating the example. It's exactly the same, except now there is a scripted button that toggles the visibility of the image. It works for sighted individuals, screen reader users, zoom users, switch and keyboard users, and everyone else with a browser developed in the last 15 years.

For the handful of users whose browsers don't support <iframe> or scripting, support for @longdesc is also less likely. For most situations, I recommended the <details>/<summary> technique which is even backwards-compatible with text-only browsers like Lynx, and is a better overall approach than the iframe technique. The iframe example only exists because several longdesc proponents insisted that the external bolt-on description was a requirement for legacy longdesc and "D link" content. A standard rendered link here is a better option too, whether inside or outside of a <figcaption> element to associate it with the image.

The updated iframe vs longdesc approach (now with visible toggle button).
<http://cookiecrook.com/longdesc/iframe/>

Other, better examples of longdesc alternatives available in HTML5 today.
<http://cookiecrook.com/longdesc/>

Thanks,
James Craig

Received on Monday, 25 August 2014 19:08:56 UTC