WHATWG
2025-12-02
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00:32
<Sacha Greif>
quick question as I'm working on the State of HTML survey results: is there currently a proposal for a Datatable element?
05:42
<annevk>
keithamus: zcorpan: see above issues with the heading* attributes.
05:43
<annevk>
Sacha Greif: I'm not aware of any.
09:51
<zcorpan>
sideshowbarker: filed https://github.com/whatwg/html/issues/11977
10:06
<keithamus>
https://github.com/whatwg/html/pull/11978 /cc sideshowbarker
10:08
<sideshowbarker>
oh, didn’t yet know about the “between 0 and 8” qualification
10:08
<sideshowbarker>
I guess I’ll need to update the HTML checker to limit it to that
10:12
<sideshowbarker>
What does setting headingoffset=0 do?
10:13
<zcorpan>
sideshowbarker: the IDL attribute reflection enforces that range and values outside the range are effectively clamped by the algo
10:13
<zcorpan>
sideshowbarker: 0 does nothing
10:13
<sideshowbarker>
OK
10:13
<sideshowbarker>
then I wonder, why is 0 allowed?
10:14
<sideshowbarker>
why not limit it to 1–8?
10:14
<zcorpan>
sideshowbarker: same reason class="" is allowed
10:15
<zcorpan>
sideshowbarker: can be more convenient to set to 0 than call removeAttribute
10:15
<sideshowbarker>
I see
10:18
<zcorpan>
keithamus: I had also started a PR lol, but yours didn't include doc conf https://github.com/whatwg/html/pull/11979
10:19
<keithamus>
Oh awesome thanks!
11:21
<sideshowbarker>
zcorpan: about https://github.com/validator/validator/issues/1396, under what conditions is it conforming for the sizes attribute to be ommitted?
11:21
<sideshowbarker>

Currently in the checker, we enforce this requirement:

When the srcset attribute has any image candidate string with a width descriptor, the sizes attribute must also be specified.

11:22
<sideshowbarker>

and so this:

<img alt loading=lazy srcset="a 100w" src=a>

…currently causes the checker to report the above error message

11:23
<sideshowbarker>
ah, only if loading=lazy is also present?
11:24
<zcorpan>
sideshowbarker: https://html.spec.whatwg.org/#attr-source-sizes:~:text=selected%2E-,If,selected
11:24
<sideshowbarker>
hmm no I guess it’s not that simple and I need read the actual spec requirements…
11:25
<zcorpan>
sideshowbarker: and https://html.spec.whatwg.org/#attr-img-sizes:~:text=If%20the%20srcset%20attribute%20is%20present%20and%20has%20any%20image%20candidate%20strings%20using%20a%20width%20descriptor%2C%20the%20sizes%20attribute%20must%20also%20be%20present%2E for img
11:30
<sideshowbarker>

hmm but I see that the spec does still state this requirement:

If the srcset attribute is present and has any image candidate strings using a width descriptor, the sizes attribute must also be present.

11:30
<zcorpan>

Hmm for this

If the srcset attribute is not specified, and the loading attribute is in the Lazy state, the sizes attribute may be specified with the value "auto" (ASCII case-insensitive).

This was added so that you could have a stable layout before setting srcset when using auto-sizes (because UA style is different). But I don't know why we didn't allow any value starting with "auto,"

11:30
<zcorpan>
sideshowbarker: Yes for img it must be present
11:31
<sideshowbarker>

So the following is in fact not conforming, right?

<img alt loading=lazy srcset="a 100w" src=a>
11:31
<zcorpan>
Correct
11:32
<sideshowbarker>
OK, I ask because at https://github.com/validator/validator/issues/1396 you had identified it as valid
11:33
<zcorpan>
The rationale is: the UA style needs to be different for auto-sizes to work correctly (needs contain: size), and it wasn't web compatible to change that for img elements that omit sizes
11:33
<sideshowbarker>
but it’s an old issue (2022), so maybe it was valid at one time, back then?
11:33
<zcorpan>
We changed the spec and I forgot to comment about it there
11:34
<sideshowbarker>
no worries
11:39
<sideshowbarker>
and apologies in general for letting so many checker issues rot for so long
11:40
<sideshowbarker>
I’m going to try to get all the open ones resolved this month
11:40
<sideshowbarker>
…and then I after that I can go back to ignoring the new ones for next 3 years or whatever 😆
11:40
<sideshowbarker>
…and I can just work on writing webkit patches instead
12:27
<sideshowbarker>

zcorpan: per these requirements:

The keyword auto is a width that is computed in parse a sizes attribute. If present, it must be the first entry and the entire <source-size-list> value must either be the string "auto" (ASCII case-insensitive) or start with the string "auto," (ASCII case-insensitive).

… then the following is not actually conforming, right?

<img alt loading=lazy srcset="a 100w" src=a sizes="(min-width: 100px) 100px, auto">
13:05
<zcorpan>
sideshowbarker: right
13:05
<zcorpan>
sideshowbarker: leading space is also invalid
13:06
<sideshowbarker>
oh then that means I need to not have my checker code trimming it
16:01
<annevk>
jarhar: did you miss https://github.com/whatwg/html/pull/11878?
22:11
<TabAtkins>
annevk: I've just been through all the WHATWG specs and confirmed they'll build correctly with the next release of Bikeshed (after accepting some trivial PRs I've just submitted), so I'm gonna go ahead and push the release. Please let me know if there are any unexpected issues; I've tried very hard to make things work smoothly for such a significant under-the-covers change.