[whatwg] <picture>, `img set`, and polyfills

Kang-Hao (Kenny) Lu kennyluck at csail.mit.edu
Mon May 14 20:29:16 PDT 2012

(12/05/15 7:17), Mathew Marquis wrote:
> It’s worth noting that a practical polyfill may not be possible when using `img set`, for reasons detailed at length elsewhere:
> http://www.alistapart.com/articles/responsive-images-how-they-almost-worked-and-what-we-need/
> http://www.netmagazine.com/features/state-responsive-images
> Long story short: attempting to write a polyfill for `img set` leaves us in the exact situation we were in while trying to solve the issue of responsive images strictly on the front-end. We would be saddling users with a redundant download—first for the original src, then for the appropriately-sized source if needed. 
> Where the new element would be all but ignored by existing browsers, efficient polyfills become possible. In fact, two `picture` polyfills exist today: http://wiki.whatwg.org/wiki/Adaptive_images#Functional_Polyfills

Sorry but I don't understand why <noscript> as used around <img> by
these polyfills listed can't be used along <img srcset>.

If your point is that some Web developers will not cater for NoScript
users and chose to include <img> in <picture>, I think those authors can
use <img srcset> without @src too (if I understand correctly).


More information about the whatwg mailing list