[oslc-core] Finalizing link guidance (was: Re: REMINDER: OSLC Core WG meeting tomorrow 10am US/ET)

Fri Sep 17 13:13:44 EDT 2010

Using ALM/PLM domain examples is good, as long as they match the spec.   I 
think we could run into some situations where people mistake the examples 
in the guidance as "the spec" for a particular domain.  We actually ran 
into this where some implementers thought that various options in the 
guidance were acceptable since it was labeled "guidance".  I'm not sure we 
can avoid that completely but just pointing out the advantages and 
disadvantages of these approaches.

Personally, I like domain-specific examples as it proves that it solves 
our problems as long as they are clearly marked as non-spec. (as we are 
not trying to handle magazine subscriptions even though the concepts 
apply).

Thanks,
Steve Speicher | IBM Rational Software | (919) 254-0645

> From: Dave <snoopdave at gmail.com>
> To: Arthur Ryman <ryman at ca.ibm.com>
> Cc: oslc-core <oslc-core at open-services.net>, 
oslc-core-bounces at open-services.net
> Date: 09/17/2010 01:05 PM
> Subject: Re: [oslc-core] REMINDER: OSLC Core WG meeting tomorrow 10am 
US/ET
> Sent by: oslc-core-bounces at open-services.net
> 
> On Fri, Sep 17, 2010 at 11:48 AM, Arthur Ryman <ryman at ca.ibm.com> wrote:
> > Thx for improving the example. But now I find myself asking another
> > question. Why are we using magazine subscriptions?
> 
> Because, at the time we came up with the examples, we did not have
> real domain examples yet.
> 
> 
> > This example looks technically correct, but it looks very contrived. 
If I
> > was designing a data model that involved magazine subscriptions, I 
would
> > certainly make a Subscription a first-class resource, and I would 
define
> > all the usual properties on it. In this example, somehow we have 
elevated
> > the subscribesTo property to a higher importance than the subscription
> > itself, and we have in effect turned the reified Statement into a
> > substitute for a Subscription resource. In practice, I would use a
> > hasSubscription property to relate the Customer to a Subscription.
> 
> We don't really provide guidance on how you decide whether to model a
> relationship as an intermediate resource or as a link with property
> values. Perhaps you must do this on a case-by-case basis but what is
> the thought process? I assume it is based on use cases and attempting
> to understand the queries needed to support those use cases.
> 
> 
> > I think an example should be more than technically correct. It should 
also
> > show how a technique is motivated in practice. I have to believe that
> > there is a more compelling example for the introduction of link
> > properties. We need a real-world, OSLC domain example where it becomes
> > natural to add properties to the link. If we can't find a convincing
> > example, perhaps this link guidance is not needed.
> 
> I believe we have some real examples now and perhaps we should
> consider adding them to later editions of this guidance.
> 
> Thanks,
> Dave
> 
> 
> 
> 
> >
> > Regards,
> > 
___________________________________________________________________________
> >
> > Arthur Ryman, PhD, DE
> >
> > Chief Architect, Project and Portfolio Management
> > IBM Software, Rational
> > Markham, ON, Canada | Office: 905-413-3077, Cell: 416-939-5063
> >
> >
> >
> >
> >
> > From:
> > Dave <snoopdave at gmail.com>
> > To:
> > oslc-core <oslc-core at open-services.net>
> > Date:
> > 09/16/2010 12:58 PM
> > Subject:
> > Re: [oslc-core] REMINDER: OSLC Core WG meeting tomorrow 10am US/ET
> > Sent by:
> > oslc-core-bounces at open-services.net
> >
> >
> >
> > Thanks, Jim. That looks much better. I just made the fixes you 
suggested
> > in the link guidance.
> >
> > re: formatting dates, I think we should handle that in the 
Representation
> > Guidance, which perhaps we need to formally finalize as well.
> >
> > - Dave
> >
> >
> >
> > On Wed, Sep 15, 2010 at 2:03 PM, James Conallen <jconallen at us.ibm.com>
> > wrote:
> > Some quick comments. I think Example #2 should be simplified with:
> > <rdf:RDF
> > xmlns:terms="http://example.com/terms/"
> > xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
> >
> > <terms:Customer rdf:about="http://example.com/customers/4321">
> > <terms:subscribesTo rdf:resource="
> > http://example.com/magazines/Field_and_Stream" />
> > </terms:Customer>
> >
> > <terms:Customer rdf:about="http://example.com/customers/4321">
> > <terms:subscribesTo rdf:resource="
http://example.com/magazines/Cat_Fancy"
> > />
> > </terms:Customer>
> >
> > <rdf:Statement rdf:about="">
> > <terms:expirationDate>2010-06-03</terms:expirationDate>
> > <terms:annualPriceUSD>23.95</terms:annualPriceUSD>
> > <rdf:subject rdf:resource="http://example.com/customers/4321"/>
> > <terms:delivery rdf:resource="http://example.com/terms/online" />
> > <rdf:subject rdf:resource="http://example.com/customers/4321"/>
> > <rdf:object rdf:resource="
http://example.com/magazines/Field_and_Stream"/>
> > <rdf:predicate rdf:resource="http://example.com/terms/subscribesTo" />
> > </rdf:Statement>
> >
> > <rdf:Statement rdf:about="">
> > <terms:expirationDate>2010-01-22</terms:expirationDate>
> > <terms:annualPriceUSD>15.95</terms:annualPriceUSD>
> > <terms:delivery rdf:resource="http://example.com/terms/mail" />
> > <rdf:subject rdf:resource="http://example.com/customers/4321"/>
> > <rdf:object rdf:resource="http://example.com/magazines/Cat_Fancy"/>
> > <rdf:predicate rdf:resource="http://example.com/terms/subscribesTo" />
> > </rdf:Statement>
> >
> > </rdf:RDF>
> >
> > Note I corrected the small typo (copy-paste error) with the actual 
values
> > for the expiration date and annual price for the Cat Fancy link. Also 
to
> > be consistent with the JSON version I corrected the delivery value.
> >
> > I think you'll also want to correct in Example #3 the delivery method 
for
> > the cat fancy link to mail (to be consistent with JSON 
representation).
> >
> > Finally looking at this example, especially with the JSON format, have 
we
> > given any consideration to formatting dates. For example is the first 
date
> > June 3rd, or March 6th? In RDF formats we can specify the datetime 
format
> > explicitly (i.e. ^^xsd:dateTime ). Not sure about JSON.
> >
> > <jim/>
> >
> > jim conallen
> > CAM Lead Architect
> > jconallen at us.ibm.com
> > Rational Software, IBM Software Group
> >
> >
> >
> > Dave ---09/15/2010 01:48:38 PM---Minutes have been posted here:
> > http://open-services.net/bin/view/Main/OslcCoreMeetings20100915
> >
> > From: Dave <snoopdave at gmail.com>
> > To: oslc-core <oslc-core at open-services.net>
> > Date: 09/15/2010 01:48 PM
> > Subject: Re: [oslc-core] REMINDER: OSLC Core WG meeting tomorrow 10am
> > US/ET
> > Sent by: oslc-core-bounces at open-services.net
> >
> >
> >
> >
> > Minutes have been posted here:
> >  http://open-services.net/bin/view/Main/OslcCoreMeetings20100915
> >
> > As always, feedback is most welcome.
> >
> > Thanks,
> > Dave
> >
> >
> > On Tue, Sep 14, 2010 at 8:56 PM, Dave <snoopdave at gmail.com> wrote:
> >> We will have a Core WG meeting tomorrow Wednesday September 15 at 
10AM
> >> US/ET. Here's the info:
> >>
> >> Agenda:
> >>  http://open-services.net/bin/view/Main/OslcCoreMeetings20100915
> >>
> >> If you have additional agenda items, please speak up.
> >>
> >> Telecon:
> >>  * Participant passcode: 558663
> >>  * Toll free: 1-866-423-8350
> >>  * Toll: 1-719-387-8273
> >>
> >> Online meeting:
> >>  * For people outside IBM
> >>    https://www.lotuslive.com/join?schedid=4446009
> >>  * For IBM employees
> >>    https://wedc.lotus.com/meeting/join/?schedid=4446009
> >
> >>    (IBM intranet authentication required)
> >>
> >> Thanks,
> >> Dave
> >>
> >
> > _______________________________________________
> > Oslc-Core mailing list
> > Oslc-Core at open-services.net
> > http://open-services.net/mailman/listinfo/oslc-core_open-services.net
> >
> > _______________________________________________
> > Oslc-Core mailing list
> > Oslc-Core at open-services.net
> > http://open-services.net/mailman/listinfo/oslc-core_open-services.net
> >
> >
> >
> >
> 
> _______________________________________________
> Oslc-Core mailing list
> Oslc-Core at open-services.net
> http://open-services.net/mailman/listinfo/oslc-core_open-services.net