Re: targetResource wording

Thus quoth Sergey Beryozkin (~ 20-Jun-03 5:19 AM ~)...
> 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
> [...]

Suppose there are two interfaces, printing & printermgmt. Printing 
contains the operation "print" which returns a job id.  printermgmt 
contains, amongst others, the cancelJob operation.

If I print to some print endpiing with a targetResource and later decide 
to cancel it, I need to know which thing on which to perform the 
cancelJob operation. In  this case, the 'targetResource' identifies the 
printing subsystem.  Depending upon the enterprise's choices, this may 
be a server, a printer, a farm of printers in some room with a common 
manager or spooler, whatever -- we don't know.  We just know that two 
endpoints employing these interfaces refer to the same 'collected stuff' 
-- that identified by the 'targetResource'.

(Arguments about bad interface decisions are not terribly relevant. 
There will always be cases where there are different interfaces.)

If, OTOH, one could put the 'printing' and 'printermgmt' interfaces into 
the same service, this wouldn't be a problem.  But it is in the current 
thinking.

IMHO:  This issue exists ONLY because of the "service contains a single 
interface" decision.


-- 
Fred Carter / AmberPoint, Inc.

mailto:fred.carter@amberpoint.com
tel:+1.510.433.6525 fax:+1.510.663.6301

Received on Friday, 20 June 2003 14:23:48 UTC