Remove implicit value of aria-level from heading role

[melanierichards]

Addresses issue #854

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Preview | Diff

[jnurthen]

link for review

[jnurthen]

I think

If headings are organized into a logical outline, the aria-level attribute is used to indicate the nesting level.

needs rewording now that aria-level is required.

[carmacleod]

Something like:

Headings SHOULD be organized into a logical outline, and the aria-level attribute MUST be used to indicate the nesting level.

?

[melanierichards]

@jnurthen @carmacleod

In the spirit of simplifying shoulds/musts, how about:

To ensure headings are organized into a logical outline, authors MUST use the aria-level attribute to indicate the proper nesting level.

[melanierichards]

Made the suggested change!

[mcking65]

Looks good to me.

[accdc]

As a quick question about the accessibility tree mappings, what heading level will a heading have if there is no implicit level?
Thanks, Bryan

[jnurthen]

As a quick question about the accessibility tree mappings, what heading level will a heading have if there is no implicit level?
Thanks, Bryan

http://w3c.github.io/aria/#document-handling_author-errors_states-properties states

If a required WAI-ARIA attribute for a given role is missing, user agents SHOULD process the attribute as if the values given in the following table were provided.
In the table the fallback for aria-level is 2

So not supplying a heading level is now an author error, but if a browser is following the fallback guidance it should still expose it with a level of 2.

[accdc]

Excellent, thanks, that was my only concern with this.