YADIS as an abstraction layer

Lukas Leander Rosenstock webmaster at lukasrosenstock.net
Wed Nov 2 04:42:36 PST 2005

When reading all your posts I wondered why nobody got the idea of 
agreeing on a filename for identity meta data. Let's call this file, 
whatever it may be at this point, "yadis.xml". For example if I enter 
"lukasrosenstock.net" somewhere as my identity the consumer or service 
will ask for my http://IDENTITY/yadis.xml, in my case 
http://lukasrosenstock.net/yadis.xml. In this file all the capabilities, 
servers, delegates, whatever meta data ... is described and the service 
can choose what to do or if it doesn't find anything appropriate or even 
gets a 404 just tells me that my identity is incapable.
Why that solution? Well, for someone writing a huge dynamic let's say 
OpenID provider it makes not so much difference if he processes 
URL?meta=capabilities or URL/yadis.xml on the GET-request, that can for 
example be rewritten by the web server. On the other hand people who got 
their own domain and/or webspace, nearly every ISP gives some to their 
customers, can just upload a yadis.xml file. They only need to know how 
to upload some file via FTP for example, no need to deal with HTML or 
even HTTP headers, no requirements on the server (e.g. the need for 
dynamic pages, there is webspace without even PHP,SSI support etc.). He 
doesn't even need to setup a homepage.
This method is efficient because no unnecessary overhead is transferred. 
Users who just watch someone's homepage don't need all those link-stuff 
in the head, identity servers just want the capabilities and don't need 
the HTML.
What do you think?


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