TinyMCE strips WAI-ARIA attributes

[paulschreiber]

WAI-ARIA attributes are stripped when switching from Text to Visual mode.

Attributes that should be allowed:
role
aria-hidden
aria-checked
aria-selected
aria-pressed
aria-label
aria-labelledby
aria-disabled
aria-grabbed
aria-controls
aria-describedby
aria-required
tabindex

[azaozz]

Related: #30421.

Would be best if this is fixed upstream in TinyMCE. Looking at https://core.trac.wordpress.org/ticket/30421#comment:25, not sure if we would want to allow all of the above attributes. For example I've seen a lot of misuse of tabindex. However all WAI-ARIA attributes should probably be allowed by default in the editor.

[paulschreiber]

Filed TinyMCE issue: ​https://github.com/tinymce/tinymce/issues/3402

[azaozz]

I believe this is fixed in TinyMCE 4.6.3 in WordPress 4.8.