[oslc-core] Example of a self-subject query capability

Tack Tong tacktong at ca.ibm.com
Mon Apr 26 16:06:22 EDT 2010


Dave,

Not sure why there is much difference.

It would be

<ems:ProjectList xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:dc="http://purl.org/dc/terms/" xmlns:ems="
http://open-services.net/software-metrics/"
   rdf:about="http://braintwistors.example.com/ems10/Project">
   <ems:memberProject rdf:resource="
http://braintwistors.example.com/ems10/Project/2009" />
</ems:ProjectList>

vs.>

<rdf:RDF>
<ems:ProjectList xmlns:rdf=".http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:dc="http://purl.org/dc/terms/" xmlns:ems="
http://open-services.net/software-metrics/"
   rdf:about="http://braintwistors.example.com/ems10/Project">
   <ems:memberProject rdf:resource="
http://braintwistors.example.com/ems10/Project/2009" />
</ems:ProjectList>
</rdf:RDF>:

The former one is more natural for representing a resource as the same way
other resources are represented. I like to see using <rdf:RDF> as an
exception only. i.e. in cases we can't do without.


Tack Tong
IBM Rational software
tacktong at ca.ibm.com
905-413-3232
tie line 313-3232

------------------------------

Message: 5
Date: Mon, 26 Apr 2010 15:08:36 -0400
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
Subject: Re: [oslc-core] Example of a self-subject query capability
             representation?
Message-ID:

<x2v8fb9ac721004261208g698b17e9s99c4ab3e200afdd0 at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

I think the differences in format are pretty different. In one case
you have a response that contains a sequence of resource
representations, each with properties, and in the other case you get
one resource with a multi-valued property that has resource
values-types.

Conceptually, this may make sense but I think it is pretty hard to
explain to consumer and provider implementations. Can't we just have
one format of query response?

- Dave



On Mon, Apr 26, 2010 at 2:58 PM, Arthur Ryman <ryman at ca.ibm.com> wrote:
> Dave,
>
> It is very easy to convert the format of a single-subject response into a
> multi-subject reponse that just has one subject. You merely put the
> single-subject response inside <rdf:RDF> ... </rdf:RDF>. I don't think
> this is a big burden for parsers (i.e. to logically supply rdf:RDF if it
> is missing).
>
> The single-subject response is similar to the representation you get from
> an HTTP GET on a resource URL without any query parameters, and that one
> has no rdf:RDF. On the other hand, a multi-subject response MUST in
> general start with rdf:RDF. ?So I think we need both (unless we are happy
> requiring ALL RDF/XML representations to start with rdf:RDF).
>
>
> 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
> Twitter | Facebook | YouTube
>
>
>
>
>
>
>
> From:
> Dave <snoopdave at gmail.com>
> To:
> oslc-core <oslc-core at open-services.net>
> Date:
> 04/26/2010 02:38 PM
> Subject:
> Re: [oslc-core] Example of a self-subject query capability
representation?
> Sent by:
> oslc-core-bounces at open-services.net
>
>
>
> Thanks Arthur,
>
> That is very helpful and I think I understand how single-subject query
> responses are formed.
>
> My next question is this: is it possible for us to continue to have
> two different conceptual types of queries (single and multi-subject)
> but to use the very exact same response representation for both? This
> would be very helpful to clients, who would not have to maintain two
> separate code paths for parsing OSLC query results.
>
> - Dave
>
>
>
> On Mon, Apr 26, 2010 at 2:27 PM, Arthur Ryman <ryman at ca.ibm.com> wrote:
>> Dave,
>>
>> The example query response in the core spec is a mult-subject response
>> since it begins with <rdf:RDF>.
>>
>> A "container" resource or a "collection" resource is a plain old
> resource
>> that has some multi-valued property that we regard as a membership
>> property. The values of this property are the members of the
>> container/collection/list/... We can filter, sort, etc. this set of
>> members using "member list pattern" queries.
>>
>> The core spec links to examples of self-subject query responses [1]. For
>> example, the resource ?http://braintwistors.example.com/ems10/Project is
> a
>> container resource that contains the list of all project resources. It
> has
>> a multi-valued property ems:memberProject that refers to the member
>> projects.
>>
>> <ems:ProjectList xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>> ? xmlns:dc="http://purl.org/dc/terms/" xmlns:ems="
>> http://open-services.net/software-metrics/"
>> ? rdf:about="http://braintwistors.example.com/ems10/Project">
>> ? <dc:title>BrainTwistors Corp. Project List</dc:title>
>> ? <dc:description>
>> ? ? ?This is the list of all Project resources contained in
>> ? ? ?BrainTwistors Corp. MetricServer web application.
>> ? ? ?</dc:description>
>> ? <ems:service rdf:resource="http://braintwistors.example.com/ems10" />
>>
>> ? <ems:memberProject rdf:resource="
>> http://braintwistors.example.com/ems10/Project/2009" />
>> ? <ems:memberProject rdf:resource="
>> http://braintwistors.example.com/ems10/Project/3707" />
>> ? <ems:memberProject rdf:resource="
>> http://braintwistors.example.com/ems10/Project/3998" />
>> ? <!--
>> ? ? ?Other members of this ProjectList resource have been
omitted for
>> ? ? ?brevity.
>> ? -->
>> </ems:ProjectList>
>>
>> The following query filters the project list:
>>
>> http://braintwistors.example.com/ems10/Project?oslc.where=dc:identifier=
>> "2009"
>>
>> The query response is:
>>
>> <ems:ProjectList xmlns:rdf="
http://www.w3.org/1999/02/22-rdf-syntax-ns#>>"
>> ? xmlns:dc="http://purl.org/dc/terms/" xmlns:ems="
>> http://open-services.net/software-metrics/"
>> ? rdf:about="http://braintwistors.example.com/ems10/Project">
>> ? <ems:memberProject rdf:resource="
>> http://braintwistors.example.com/ems10/Project/2009" />
>> </ems:ProjectList>
>>
>> [1]
>>
>
http://open-services.net/bin/view/Main/OslcSimpleQuerySemanticsV1#Examples
>> 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
>> Twitter | Facebook | YouTube
>>
>>
>>
>>
>>
>>
>>
>> From:
>> Dave <snoopdave at gmail.com>
>> To:
>> oslc-core <oslc-core at open-services.net>
>> Date:
>> 04/26/2010 12:45 PM
>> Subject:
>> [oslc-core] Example of a self-subject query capability ?representation?
>> Sent by:
>> oslc-core-bounces at open-services.net
>>
>>
>>
>> I need a little help understanding the most recent changes in the
>> Query Capabilities section of the spec. We now have two types of query
>> capabilities, multi-subject and self-subject but we only illustrate
>> multi-subject queries in our examples. I'm trying to understand what a
>> self-subject query response would look like. Here's how it is
>> described in the Core spec:
>>
>> "The RDF/XML representation of the query result begins with a node
>> element whose rdf:about attribute value is equal to the base URI.
>> Typically, the base URI is a container resource that may have a long
>> list of members, e.g. the list of all defects in a bug tracking
>> system. Since the list may contains hundreds of thousands of members,
>> queries are used to filter the list for members that satisfy certain
>> conditions, e.g. the bugs that have high priority and were created
>> this week."
>>
>> I don't know what "the base URI is a container resource that may have
>> a long list of members" means. Are we using a multi-valued property
>> here to hold the resources that match the query? Tack or Arthur, would
>> one of you please provide a simple example of a self-subject query
>> response?
>>
>> 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
>
>
>
>



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