Add aria-describedby to autofocused fields

[joedolson]

There are various areas in the WordPress admin where autofocus is used to push focus to a particular location on a screen. These need to be reviewed to address whether the context is clear to screen readers, and add an appropriate aria-describedby attribute so that the context of the focused field is adequately clear.

I'll address this early in the 4.2 cycle.

[joedolson]

Notes: it appears that the function install_theme_search_form(), which used autofocus is no longer used. It may be worthwhile to go through and remove the old code. When the theme search was replaced, it looks like all the add_action() calls in theme-install.php were just commented out, but the code hasn't been pulled out.

Most of the uses of autofocus appear to be in the customizer or tinymce at this point; it appears that most of the search forms that used to take autofocus have been replaced in recent versions.

In the customizer, I think that the button labels *may* be sufficiently clear, but confirmation of location would probably be valuable. For the header image, all that's read is "Add new image". You have just activated the link "Header", but confidence that you're in the right place would be beneficial.

The background image is theoretically fine, because that control includes a label. But a button with a label only reads out the label, and not the button text.

Patch adds an aria-label to the Header image button that gives context.

I'm not sure where to go to address the background image. This could be solved by adding an aria-labelledby with two ID references - one to the label and one to the button. Or it could be solved with an aria-label that provided full context.

The third autofocus area in core is the Widgets panel; right now, that doesn't really seem to do anything - focus is actually placed on the back button in the customizer, not the widgets panel. I think that if the section title received focus, that would be just fine.

[joedolson]

Add aria-label to header image control.

[obenland]

@joedolson, is the patch all that needs work? You mentioned reviewing "various areas in the WordPress admin".

[joedolson]

Most of the areas that used to use autofocus seem to be gone, so there's less that's relevantt. It turns out that there isn't a lot of autofocusing going on in the WP admin anymore, at least, not that I could find by searching for 'autofocus'.

Unless more autofocus has been added in the last 6 weeks; I haven't checked that.

[obenland]

Do you want to add something for background and widgets as well, or is headers the only place where we need more context?

[obenland]

In 33158:

Better context for autofocused elements for screen readers.

Props joedolson for initial patch.
Fixes #30706.