OpenID Login Page Link Tag

[Martin Atkins]

Drummond Reed wrote:
> I initially agreed as well. But to play devil's advocate, the link-to-XRDS
> option could actually be pretty efficient. Any HTML page could simply
> advertise the availability of its Yadis XRDS file using an XRDS link in the
> header. Assuming that many or all of the pages on a site would be covered by
> the same XRDS file, the browser would only need to download it once to cover
> the entire site. The XRDS would expire (using the same cache control that
> XRI resolvers use) and be refreshed as needed.
> 
> This is the architecture that P3P used
> (http://www.w3.org/TR/P3P/#ref_syntax). 
> 
> The XRDS file could provide discovery of multiple services representing the
> RP, not just the login page.
> 

This is not incredibly different to what happens when you have a 
site-wide CSS stylesheet. In fact, it is possibly *better* than that 
situation since you don't need to delay page rendering while waiting for 
the Yadis document to download.

I wonder, though, whether we are asking too much of browsers' plugin 
interfaces? This is an honest question, as someone who's never written a 
browser chrome plugin before.

I guess IE's ones are just COM objects and can thus do whatever they 
like, but what of Firefox? Chrome overlays? Does that mean that they can 
access the HTTP component somehow to make HTTP requests?

I think Opera's pretty unlikely as it has no real plugin interface to 
speak of. I have no idea at all about Safari.

Anyone care to elaborate? There's no point in speccing something that's 
unimplementable, but it's probably okay as long as IE and Firefox can do 
it; the others can just catch up later.