Fw: Content Negotiation and Adaptation, Why and How .. ?

> the question that i have is: This operation can be done by a proxy or

> an intermediary element?



Applying a style sheet or another kind of adaptation method is called the
"content adaptation" and can be

applied by the original server or an intermediate proxy. The content
adaptation is applied when:

1- The original content can't be used directly by the client

and

2- There is no existed version (or 'variant' using the HTTP vocabulary!)
that meet the need of the client

and

3- The service or document provider has an adaptation method which can
transform the original content to

another content that respects the target context.



> for example, the proxy do a xml (http) request to the server, and the

> conversion is made in the proxy.

> I have heard it but i am not sure that it would be true.



Before choosing the adaptation method to apply or the selected version to
deliver, the content negotiation

step must be achieved. To achieve this task, some information are needed
such as information about: the user

agent profile, the requested content, the server capabilities etc.

The more suitable situation to use an advanced content negotiation is to
include the negotiation module at the

server side, and to provide other required information such as the document
profiles (document characteristics,

document meta data, etc.). The use of the proxy based architecture can be
more suitable if we target some well

known adaptation or transcoding. This why in the literature we find proxies
like image transcoding proxies,

HTML to WML proxies etc.



Hope this will help.


regards

----------
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.

----- Original Message -----
From: <norberto@eresmas.com>
To: <Tayeb.Lemlouma@inrialpes.fr>
Sent: Thursday, March 14, 2002 12:12 PM
Subject: Content Negotiation and Adaptation, Why and How .. ?


> hello,
> my name is Norberto Chatlani, from Spain, and i have started to study
> xml, xsl, and finally found cc/pp. while i was doing this trip, tried
> to understand cc/pp how works it.
> the information is in xml format.
> the webserver looks the request and what kind of client do the request
> (User Agent Profile).
> According to this profile, use the stylesheet apropiated.
>
> the question that i have is: This operation can be done by  a proxy or
> an intermediary element?
> for example, the proxy do a xml (http) request to the server, and the
> conversion is made in the proxy.
> I have heard it but i am not sure that it would be true.
>
> thanks
> norberto chatlani
>
>
>
>

Received on Thursday, 14 March 2002 08:36:37 UTC