[a11y] Qtable compatibility with RGAA (French WCAG)

[NPi2Loup]

Hello !
We're working on a French public portal.
An external agency has carried out an accessibility audit. Its similar to #16109 .
But all improvements are welcome, which is why I'm putting here those that concern QTable only, and which could be handled independently of other corrections.
These corrections are easier to make directly in QTable than in a project, and improve Quasar's overall accessibility.

Table

The <table> tag must define a title. There are 4 possibilities:

• Add a <caption> tag.
• add a title attribute
• add an aria-label attribute
• add an aria-labelledby attribute.

At present, we don't know how to add an attribute to the <table> tag itself.
The aria-label attribute is perhaps the simplest solution. And the caption may be more complex as it needs to be hidden from the standard user.

Th

The <th> tags must have a scope=col attribute.
Currently, we have to rewrite all headers with the header-slot.

Best regards,

[NPi2Loup]

I've just proposed a fix to these problems:
NPi2Loup@5cec534

Is a PR not related to an issue accepted?

[NPi2Loup]

Some fix after Dan review NPi2Loup@e09c675

[NPi2Loup]

After a few explanations from our expert, it seems that using aria-label on <table> is not right in our case.
Indeed, if the table has a title, aria-labelledby should be used.
Fortunately, QTable adds the title and the table, so we can correlate them.

I'm going to propose some code.
What's the "right" way to add a random identifier to quasar? (to put it on .q-table__title and add aria-labelledby on <table>)

[yusufkandemir]

Use uid() to generate a unique identifier, set it as the id of the title, and set it as the aria-labelledby of the table. See an example implementation in QFab here.

[NPi2Loup]

I will, thank you

[NPi2Loup]

Done : NPi2Loup@395501c

I set the titleUid into marginalsScope because we need it when we override header-slot.
(In fact we override it to set a correct hx tag for title. WCAG rule)

[NPi2Loup]

How do I propose this code to the Quasar team ?
I've read https://github.com/quasarframework/quasar/blob/dev/CONTRIBUTING.md#pull-request-guidelines
Do I just have to make a PR on dev ?
Is a PR related to a11y considered as an issue ? as a new feature ? I think it's somewhere in between.

[NPi2Loup]

WCAG references :
https://www.w3.org/WAI/tutorials/tables/caption-summary/
https://www.w3.org/WAI/tutorials/tables/one-header/