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Re: table cells, th-mapping

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From: Jonathan Avila
Date: Mar 16, 2021 10:02AM

Glenn, I think it's say a td could point to another to the id of td or th that then points to another th - sort of chaining of headers without directly referencing them.

Jon

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From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of glen walker
Sent: Tuesday, March 16, 2021 11:54 AM
To: WebAIM Discussion List < <EMAIL REMOVED> >
Subject: Re: [WebAIM] table cells, th-mapping

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Ah, yes, thanks Jonathan.

But there's also the difficult to understand section of the headers spec (
https://www.w3.org/TR/html53/tabular-data.html#element-attrdef-tablecells-headers)
that says

A th <https://www.w3.org/TR/html53/tabular-data.html#elementdef-th> element A is said to be *targeted* by a th or td <https://www.w3.org/TR/html53/tabular-data.html#elementdef-td> element B if either A is *directly targeted* by B or if there exists an element C that is itself *targeted* by the element B and A is *directly targeted* by C.

I had to read that a dozen times to get it. A td directly targeting a th via the headers attribute is valid but a td can also target a separate element (C) if C directly targets the th. I'm not sure how to code that because even if I could have the td point to the span via headers, I could not point the span itself to the th via headers because headers is not a valid attribute for a span.



On Tue, Mar 16, 2021 at 9:40 AM Jonathan Avila < <EMAIL REMOVED> >
wrote:

> It's my understanding that the spec says the ids must point to TH
> cells themselves and not something else like a span inside of them.
>
> https://html.spec.whatwg.org/multipage/tables.html#attr-tdth-headers
>
> Jonathan
>
>