Re: Priority Hints - fetchpriority and iFrames

Hi Patrick,

I think Gecko is implementing it, do you mind file a spec issue so that I
can let more folks to take a look?

Thanks!
Sean

On Thu, Feb 16, 2023 at 1:48 PM Patrick Meenan <pmeenan@google.com> wrote:

> Would anyone be particularly concerned if we removed iFrames from the list
> of elements that support fetchpriority?  It's not currently implemented in
> Chrome and as we go through the spec process, it isn't immediately clear
> that trying to prioritize the document fetch is the best way to control the
> scheduling of the iFrame.
>
> Specifically:
>
> - The fetch will be in a different document context from main-document
> subresources and may not be able to be scheduled within the browser
> relative to the other requests.
>
> - The network fetch may not be on a connection where it could be
> prioritized against other requests (even if they happen to be from the same
> origin) depending on how browsers choose to partition the network state
> across frames for privacy.
>
> - It doesn't control the scheduling of non-fetch iFrames.
>
> I'm thinking that we'd be better off thinking about scheduling of iFrame
> instantiation as it's own thing with imperatives that match what dev's
> would like to control.  i.e. would a "defer" make sense for an iframe to
> delay starting the loading of an iframe until the main DOM is ready?  Kind
> of like there's already loading=lazy for matching the image behavior.
>