LGTM2 On Wed, May 21, 2025 at 6:34 PM Vladimir Levin <vmp...@chromium.org> wrote:
> CSSWG resolved on this issue > https://github.com/w3c/csswg-drafts/issues/10982#issuecomment-2898572289 > I believe this aligns with option 2 in Yoav's reply. > > LGTM1 > > Thanks, > Vlad > On Wednesday, May 21, 2025 at 3:48:18 AM UTC-4 Rune Lillesveen wrote: > >> On Tue, May 20, 2025 at 1:38 PM Yoav Weiss (@Shopify) < >> yoavwe...@chromium.org> wrote: >> >>> >>> >>> On Tue, May 20, 2025 at 1:32 PM Rune Lillesveen <futh...@chromium.org> >>> wrote: >>> >>>> On Tue, May 20, 2025 at 10:47 AM Yoav Weiss (@Shopify) < >>>> yoavwe...@chromium.org> wrote: >>>> >>>>> >>>>> >>>>> On Wed, May 14, 2025 at 6:10 PM Philip Jägenstedt <foo...@chromium.org> >>>>> wrote: >>>>> >>>>>> On Wed, May 14, 2025 at 5:21 PM Rune Lillesveen <futh...@chromium.org> >>>>>> wrote: >>>>>> >>>>>>> On Tue, May 13, 2025 at 9:20 AM Rune Lillesveen < >>>>>>> futh...@chromium.org> wrote: >>>>>>> >>>>>>>> On Tue, May 13, 2025 at 8:34 AM Rune Lillesveen < >>>>>>>> futh...@chromium.org> wrote: >>>>>>>> >>>>>>>>> On Tue, May 13, 2025 at 7:43 AM Domenic Denicola < >>>>>>>>> dome...@chromium.org> wrote: >>>>>>>>> >>>>>>>>>> I'm very slightly worried about the cases which we seem to >>>>>>>>>> accept, but the latest on the CSSWG thread suggests we should >>>>>>>>>> disallow. >>>>>>>>>> Namely, @container and @page. How sure are you that changing those >>>>>>>>>> to be >>>>>>>>>> invalid in the future, to follow the latest CSSWG decisions, will >>>>>>>>>> not cause >>>>>>>>>> compat problems? >>>>>>>>>> >>>>>>>>> >>>>>>>>> For @page, I wouldn't be worried at all. It's unlikely someone >>>>>>>>> will start using the feature and rely on a constant >>>>>>>>> sibling-index()/sibling-count() in @page. >>>>>>>>> >>>>>>>>> For @container, I agree that it's safer to be conservative and >>>>>>>>> wait for the resolution, since for @container there are clear use >>>>>>>>> cases and >>>>>>>>> and a more or less obvious behavior in that context. >>>>>>>>> >>>>>>>> >>>>>>>> Some more details below. >>>>>>>> >>>>>>>> For @container, this is relevant for size queries and style() >>>>>>>> queries. >>>>>>>> >>>>>>>> Size queries are currently always evaluated in an element context, >>>>>>>> although falling back to viewport has been discussed, and container >>>>>>>> units >>>>>>>> fall back to small viewport units. Relative units (like ems below) are >>>>>>>> evaluated against the computed values of the container element: >>>>>>>> >>>>>>>> @container (width > calc(sibling-index() * 50px)) {} >>>>>>>> @container (width > 10em)) {} >>>>>>>> >>>>>>>> >>>>>>>> For style queries, the right hand of the query is evaluated against >>>>>>>> the container element and its computed styles for registered custom >>>>>>>> properties. Note that for non-registered custom properties, >>>>>>>> sibling-index() >>>>>>>> would just be part of the string/tokens without any specific meaning. >>>>>>>> >>>>>>>> I think it would be inconsistent to reference relative units (like >>>>>>>> em below) and resolve custom properties references (like var(--a) >>>>>>>> below), >>>>>>>> but specifically throw away sibling-index() when evaluating the value >>>>>>>> against the registered syntax: >>>>>>>> >>>>>>>> @container style(--registered-length: calc(sibling-index() * 20px)) >>>>>>>> {} >>>>>>>> @container style(--registered-length: 10em) {} >>>>>>>> @container style(--registered-length: var(--a)) {} >>>>>>>> >>>>>>> >>>>>>> I'll make my position clearer. >>>>>>> >>>>>>> I think we should ship with support for tree counting functions >>>>>>> in @container because >>>>>>> >>>>>>> 1. @container queries are currently always in a (container) element >>>>>>> context and there are valid use cases >>>>>>> 2. Supporting tree counting functions in @container does not break >>>>>>> with the current spec >>>>>>> 3. I don't think it's likely there will be a resolution that >>>>>>> disallows tree counting functions in @container >>>>>>> 4. In particular, disallowing tree counting functions in style() >>>>>>> queries would be inconsistent with e.g. relative units >>>>>>> >>>>>> >>>>>> I am recused on this one, but FWIW I agree with this reasoning. >>>>>> https://github.com/w3c/csswg-drafts/issues/10982 is already Agenda+ >>>>>> >>>>> >>>>> When is the discussion scheduled to take place? >>>>> >>>> >>>> I added Agenda+ in March, but haven't pushed hard. Asked the chairs to >>>> put it on the agenda now. >>>> >>>> >>>>> and if we're confident the right solution is to match how relative >>>>>> units, then we can proceed. Rune pointed out that it's already tested >>>>>> here: >>>>>> >>>>>> https://wpt.fyi/results/css/css-values/tree-counting/sibling-function-container-query.html >>>>>> >>>>>> To ship without this behavior only to add it a few milestones later >>>>>> would complicate the browser support story and require explanation on >>>>>> places like MDN and caniuse.com. >>>>>> >>>>> >>>>> In case the CSSWG decision is made before 138 ships to stable and it >>>>> does not align with what you're proposing we ship, are you OK with >>>>> disabling the feature using its Finch flag? Or should we put @container >>>>> support behind a separate flag? >>>>> >>>> >>>> Adding a separate flag for @container here: >>>> >>>> https://chromium-review.googlesource.com/c/chromium/src/+/6563296 >>>> >>>> I'm fine with shipping support in @container later in a separate >>>> intent, when the issue is resolved, too. >>>> >>> >>> I think we have two options: >>> 1. Ship @container separately, incurring the costs Philip mentioned >>> (complex support grids, wonky feature detection (do we have a proper story >>> for that?), etc) >>> 2. Optimistically ship everything and hope that the resolution would >>> match what we're trying to ship. In case it won't, we reverse course. >>> >>> I prefer (2), and depending on the answer to my feature detection >>> question, it might be better to keep a single flag and ensure the feature >>> either ships or doesn't in its entirety. >>> >>> WDYT? Does (2) seem like a reasonable risk to take? >>> It does assume that the discussion will happen before 138 hits stable >>> though.. >>> >> >> Yes. The issue is now also the second item on the agenda for the CSSWG >> call tonight, so we'd hopefully have a resolution one way or the other. >> >> -- >> Rune Lillesveen >> >> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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