Re: What is the subject URI of a profile ?

Hi Masahide,

>I wonder how we provide a profile's subject URI, i.e. the value of the
>'rdf:about' attribute of the top 'rdf:Description' element. For example, if
>I want to define a profile for one of my browsers, what URI should be
>chosen for the profile ?

>Since we do not have a generic identifier to specify our agent or
>environment (or even ourselves), it is not obvious which URI should be
>taken. May I use my homepage URI + browser name ? (Oh, no.)  Or an empty
>string as rdf:about="" might be possible, but how could it be interpreted
>(in other words, what is the base URI of the profile which is not an Web
>resource) ?  Or just use no 'rdf:about' attribute, leaving it as blank node
>?

The "rdf:about" can have any value that allows to identify the profile of the device 
browser. In the case where profiles are stored in repository, the client profile (and consequently
the device) can be identified using the profile location in the repository server.

In the case where profiles are received by the server from the device or from other intermediate 
entity (proxy for example), the browser (and the device) could be identified using other additional information.
An example of such additional information: the header fields of HTTP requests (user agent, etc.)

In the two precedent situations, the server must find (or associate) the appropriate information of the profile to 
the user involved in the current client/server session. This problem is not present in the situation where 
the device sends its profile during the client/server session. However, in the other case, the server can  
identify the browser using the request information sent by the browser: a good example is the "user agent" 
header field of HTTP requests, unfortunately the "user agent field" and other fields don't reflect always the 
reality of the browser, this is why applications developers should be aware to send the correct information. 


Regards

Tayeb*
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Tayeb Lemlouma
http://www.inrialpes.fr/opera/people/Tayeb.Lemlouma/index.html
Opera project
National Research Institute in Computer Science and Control (INRIA Rhône-Alpes, France )
Office B213, phone (+33) 04 76 61 52 81, Fax (+33) 04 76 61 52 07.