[whatwg] Implementation complexity with elements vs an attribute (responsive images)

[James Graham]

On Sat, 12 May 2012, Boris Zbarsky wrote:

> On 5/12/12 9:28 AM, Mathew Marquis wrote:
>> While that information may be available at the time the img tag is parsed, 
>> I don’t believe it will be available at the time of prefetching
>
> Which information?
>
> At least in Gecko, prefetching happens "when the tag is parsed".
>
> So in fact in Gecko the srcset approach would be much more amenable to 
> prefetching than the <picture> approach.

Yes, I should have mentioned that is also true in the various types of 
optimistic resource loading/parsing that Opera does e.g. the delayed 
script execution mode and the speculative tokenisation feature.