Implementing YADIS with no new software

Mon Oct 31 10:17:58 PST 2005

On Oct 31, 2005, at 11:40 AM, Benjamin Yu wrote:

> 2. What about embedding the capabilities information in the  
> identity URL's
> document instead of linking to another static doc? I'm not saying  
> that I am
> really advocating this position, just bringing it up for a pro/con  
> discussion.

Isn't this what <link rel="" ...> is for?  I am going to think out  
loud for a bit; please bear with me.

Could we do:

<link rel="yadis.server.openid" href="OpenID server target" />
<link rel="yadis.server.lid" href="LID server target" />
<link rel="yadis.server.newidentityprotocol"  
href="NewIdentityProtocol (not a real identity protocol) server  
target" />

What about things that don't use a URL?  For the sake of generating  
an example, I'll pretend that TypeKey doesn't have OpenID support.   
One could perhaps then do:

<meta name="yadis.name.typekey" content="TypeKey username" />

So suppose an example page has more than one of the above statements,  
and an example multi-protocol consumer supports several of those  
protcols.  How to choose between them?

How about:
<meta name="yadis.protocols.preference" content="openid; q=0.9, lid;  
q=0.5, typekey; q=0.3">

This is modeled after the HTTP Accept header format but obviously it  
is open to change.

Profile exchange?  How about:
<link rel="yadis.profile.vcard" href="" />

Again, if multiple formats are given for the profile, a tag could be  
used to indicate which is preferred.

This sort of thing works well with existing documents (whether static  
or dynamic), and requires nothing more than a few tags in the  
<head>.  The only problems is that it is (X)HTML-specific.  This has  
been raised before in terms of decoupling OpenID from (X)HTML, and I  
don't believe a satisfactory resolution was ever reached on that issue.

-Kurt