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

Mon Apr 26 14:58:44 EDT 2010

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
>
>
>
>

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