Issue-742: Proposal aria-destination

This is not a formal proposal but one that would seed a formal proposal if
the group agrees. I would need to coordinate with coga and the aria-dpub
folks. Normally I would push this to ARIA 2.0 but because we have two
efforts wanting essentially the same thing and I don't want to have
multiple roles for a link I believe this is a better approach.

aria-destination - Provides the context of a link.

This attribute provides contextual semantics for the destination of a link
so that authors may use this information to drive a consistent user
interface. Some assistive technologies may this information important to
provide to assistive technologies.

The following is a list of possible values that the destination could take
on from the coga task force and I suggest we consider a subset of these:

      home
      contact us
      our phone
      our email
      site map
      help
      about us
      terms
      tools
      comment
      language (English)
      sign in
      sign up
      product
      services
      social (provide label - such as facebook twitter)
      post
      contactus
      Help
      Chat help

This is based on this wiki:
https://rawgit.com/w3c/coga/master/issue-papers/links-buttons.html

I introduce this now as the dpub aria task force roles for different types
of links which reflect the destination of the link provided. Since both
task forces need a feature like this we should place an anhor inside ARIA
1.1 so that they mau build off it.

The current Digital Publishing WAI-ARIA module (
http://rawgit.com/w3c/aria/master/aria/dpub.html) has these roles:

doc-biblioref: A reference to a bibliography entry.
doc-glossref: A reference to a glossary definition
doc-location: A link that allows the user to jump to a related location in
the content (e.g., from a footnote to its reference, from an index entry to
where the topic is discussed, or from a glossary definition to where the
term is used).
doc-noteref: A reference to a footnote, typically appearing as a
superscripted number or symbol in the main body of text.

I recommend these be additional tokenized values, without the doc-, for
aria-destination and a subset of what coga would like for ARIA 1.1. The
Coga task force can then expand on the values.

example:
style {
a[a[aria-destination="glossref"] {
    background-color: yellow;
    border: 2px blue;
}
div[role="link"][aria-destination="glossref"] {
    background-color: yellow;
    border: 2px blue;
}

<a aria-destination="glossref" href="..." >discombobulated</a>


Rich Schwerdtfeger