`logo-href` for revealjs, dashboard

[gordonwoodhull]

I'm going to open another issue for logo-href (are people also going to expect logo.href?)

I see logo-href is supported by navbar and sidebar but not dashboard.

Originally posted by @gordonwoodhull in #10933

[mcanouil]

Only the dash one as it's the syntax for option in Quarto.

[cwickham]

When logo-href lands for dashboards, it would be nice if false were a supported value to opt out of the link entirely, mirroring logo: false. On single-page dashboards that could arguably be the default.

Some context from testing the current hardcoded href="#" (_nav-container.html#L3-L4) on 1.10.12. On a multipage dashboard the link works as a back-to-first-page control, because emptying the hash makes the page router activate the first tab (quarto-dashboard.js#L233-L241). That's undiscoverable and redundant with the first nav tab, but it does something. On a single-page dashboard there are no tabs, so the logo is a keyboard tab stop and a screen-reader link-list entry whose only effect is changing the URL to …#. If the author hasn't set logo alt text it's also an unnamed link (axe link-name, serious).

The opt-out can be a one-attribute change. Rendering the <a> without href leaves an unfocusable element that screen readers pass through, while the logo <img> is still announced from its plain alt. Verified in the accessibility tree that no ARIA is needed.

(AI-assisted investigation, grounded in a local clone of this repo, per CONTRIBUTING.md.)