a11y-dialog VS dialog-polyfill

If it's a warning it should probably be role="alertdialog" rather than role="dialog". This will allow assistive devices to prioritize its content and trigger things like an alert sound. You probably also want to put keyboard focus on the least destructive action, which in your case would be the "save changes" button, rather than leaving keyboard focus above the close button. Here's a script by Kitty Giraudel that will do most of this for you, if you want.

On that note, TIL about screen reader issues related to dialogs in general, including this built-in. Seems like the question is primarily around how to update the focus target from the "invoking element" to the dialog's content in a reader-friendly way. There's a linked post from the MDN docs with more detail https://www.scottohara.me/blog/2019/03/05/open-dialog.html#i.... They actually still recommend a custom implementation that's considered more robust when used with screen readers: https://github.com/KittyGiraudel/a11y-dialog. I'm glad there's a callout on the MDN docs as I would have assumed this dialog element is screen reader clean. Focus management is always a tough thing regardless.

> - Z-index has no effect in the top-layer. No need to compete for a higher z-index.

This is the kind of boring feature that can end up saving huge amounts of developer time. Z-indexing in CSS is kind of annoying and I've seen projects just detach dialogs from their normal position in the DOM entirely to get around stacking errors before.

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Minor question:

> - There is only one `top-layer` but it can have many children. Last opened === current element on top.

Is this true? The spec says:

> The top layer is an ordered set of elements, rendered in the order they appear in the set. The last element in the set is rendered last, and thus appears on top.

I'm still playing around with `dialog` elements, so you may well be right, I'm just having trouble finding the actual spec rules about what happens when there are multiple dialogs and they're being simultaneously manipulated.

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> - Not supported in Safari <= 15.3

Worth noting that there is a polyfill (https://github.com/GoogleChrome/dialog-polyfill), but that the polyfill comes with some fairly large limitations, specifically that they don't advise dialogs be used as children of elements with their own stacking context.

This is reasonable, but also... my first thought when I originally ran into `dialog` was "finally I can stop worrying about which of my elements create new stacking contexts!" -- so it does decrease the usefulness quite a bit.

Yeah, Safari is pretty often behind the other popular browsers. But, you can generally predict that by looking for any given feature on MDN and check the "Browser compatibility" section. Sometimes, there are polyfills available that sort of "force" a feature to work across every browser.

(Searching for "polyfill " will usually get you good results - in this case the first result appears to be a library maintained by the Chrome team: https://github.com/GoogleChrome/dialog-polyfill )

This does not make sense. Of course new functionality won't work on old browsers.

is easy to polyfill well: https://github.com/GoogleChrome/dialog-polyfill

GoogleChrome / dialog-polyfill