Re: [csswg-drafts] [css-anchor-position-2] Add a `fallback` feature for querying applied fallback for anchored elements (#12391)

The CSS Working Group just discussed ``[css-anchor-position-2] Add a `fallback` feature for querying applied fallback for anchored elements``, and agreed to the following:

* `RESOLVED: define a fallback container feature used in the anchored query function`

<details><summary>The full IRC log of that discussion</summary>
&lt;JoshT> futhark: the next thing is to add something to query about these anchored elements<br>
&lt;JoshT> ... query the fallback position of the anchored element<br>
&lt;JoshT> ... to add a new anchored() function to the container root<br>
&lt;JoshT> ... a single feature for now to query the fallback pos used by the anchored element<br>
&lt;JoshT> ... this fallback pos is matching either the name from the fallback being applied or the position area<br>
&lt;JoshT> ... set by the position try fallbacka<br>
&lt;JoshT> ... the position area will match not the keyword but on the physical position, so you can use logical values to match<br>
&lt;JoshT> fantasai: overall seems reasonable. sad it has to be a container query rather than query on the item itself<br>
&lt;kizu> q+<br>
&lt;JoshT> futhark: the thing on the element itself is already limited to certain properties for anchored elements already, for the fallback styling<br>
&lt;astearns> ack kizu<br>
&lt;miriam> q+<br>
&lt;JoshT> kizu: only question about position area<br>
&lt;JoshT> ... should it match exactly or match partially<br>
&lt;JoshT> ... say you position stuff to the bottom, but it could be bottom-right, bottom-center<br>
&lt;JoshT> ... could you query this 'somewhere on the bottom' without the exact area<br>
&lt;JoshT> futhark: my proposal was to match exactly but that could make sense to have a syntax for matching some area<br>
&lt;JoshT> ... i'm not sure what the syntax would look like<br>
&lt;JoshT> fantasai: we discussed this when designing the matching syntax as a thought experiment at apple<br>
&lt;JoshT> ... I remember a matching syntax to query ???. I'll see if I can find anything<br>
&lt;JoshT> ... yeah we allow the keyword 'any' in some places<br>
&lt;JoshT> futhark: so you could say span left or something?<br>
&lt;kizu> I like `any`<br>
&lt;JoshT> fantasai: span left any. and it would be either left-top, left-bottom, etc<br>
&lt;fantasai> s/span left/span-left/<br>
&lt;JoshT> astearns: should we decide on that today or give more time for thought?<br>
&lt;JoshT> futhark: we could resolve on what I've proposed today and create an issue to add 'any'<br>
&lt;astearns> ack miriam<br>
&lt;JoshT> miriam: this might also belong in a separate issue, but wondering if there's other cases where we have container query syntax in a if function<br>
&lt;JoshT> ... does this have if function uses?<br>
&lt;JoshT> TabAtkins: no because this has to be on the container. can't query on the element itself for bad cyclic reasons<br>
&lt;JoshT> miriam: OK<br>
&lt;JoshT> PROPOSED: add anchor query function that can take fallbacks as params<br>
&lt;JoshT> futhark: it includes having a fallback container feature, not a fallback value directlu<br>
&lt;JoshT> PROPOSED: define a fallback container feature used in the anchor query function<br>
&lt;JoshT> PROPOSED: define a fallback container feature used in the anchored query function<br>
&lt;JoshT> RESOLVED: define a fallback container feature used in the anchored query function<br>
&lt;JoshT> astearns: who will open issue about any keyword?<br>
&lt;JoshT> futhark: can unless fantasai wants to<br>
&lt;JoshT> astearns: please do!<br>
</details>


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Received on Wednesday, 13 August 2025 16:53:42 UTC