W3C home > Mailing lists > Public > www-ws-desc@w3.org > June 2003

Re: targetResource wording

From: Sergey Beryozkin <sberyozkin@zandar.com>
Date: Fri, 20 Jun 2003 14:58:42 +0100
Message-ID: <002301c33734$0f7b9410$1800a8c0@BERYOZKIN>
To: <www-ws-desc@w3.org>, "Arthur Ryman" <ryman@ca.ibm.com>
Hello Arthur,


>In the case that two services implement the same interface AND have the same target >resource, then they are alternatives. The client can pick the service that offers the most >appropriate binding or endpoint.

I can see this practical implication, thanks.   
But a single service description with multiple ports can provide the same choice for a client, can't it ? Every port within a service is an alternative way to access a single interface in WSDL 1.2, which  allows to select both the best endpoint and the best binding.

It's just many mails on the subject refer to a case  where two services implementing *different* interfaces (print and printManager, for example) refer to the same target (printer) resource. And I can't figure out how this knowledge can help a developer (or toolkit) make it easier to manage and print (something that could be done without a @targetResource) ?

Or may be the printManager service implements both printer and printManager interfaces through inheritance ? If so, then it may explain why @targetResource can let a client to choose a printManager service only, and both manage and print.

Or may @targetResource will be used when there're a lot of printManager services, and all of them are managing a unique printer resource. In this case, a client, before asking a printer service to print at a printer 'A', will quickly discover a printManager managing 'A' and set 'A' appropriately ? This scenario seems to explain to me why @targetResource is there, am I wrong here ?

Cheers !
Sergey Beryozkin
 
  ----- Original Message ----- 
  From: Arthur Ryman 
  To: www-ws-desc@w3.org 
  Sent: Friday, June 20, 2003 1:38 PM
  Subject: Re: targetResource wording



  Sergey, 

  I think there is also a practical implication. In the case that two services implement the same interface AND have the same target resource, then they are alternatives. The client can pick the service that offers the most appropriate binding or endpoint.

  Arthur Ryman 



       "Sergey Beryozkin" <sberyozkin@zandar.com> 
        Sent by: www-ws-desc-request@w3.org 
        06/20/2003 08:19 AM 

               
                To:        "Sanjiva Weerawarana" <sanjiva@watson.ibm.com>, <www-ws-desc@w3.org> 
                cc:         
                Subject:        Re: targetResource wording 

                



  Sorry for asking what likely is a trivial question, but :

  > > Can a client processing service d1 and d2 descriptions to avail of this
  > > targetResource attribute in any way ?
  >
  > Sure- to realize that d1 and d2 both have something on common: they
  > are both services that mess around with the same resource.
  So, for example,  a client sees a printer service which can print a document
  to a printer (identified by a targetResource), and also sees a printer
  management service which can manage the same targetResource.
  I can't see at the moment how the client can utilize this information. Say,
  a client now can set up a printer first before sending a document to print ?
  But wouldn't a client be able to do the same if there were  two services
  descriptions available (printer and printer manager) but without a
  @targetResource ?

  Thanks !
  Sergey Beryozkin
Received on Friday, 20 June 2003 09:58:38 GMT

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