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

Mon Apr 26 15:44:55 EDT 2010

Dave,

The most frequent case would be a self-subject query since any resource 
can be its base URL. The Query Capabilities then simply identify a few 
root resources to start off the discovery process. That is what Reporting 
is supporting. 

The multi-subject case allows some additional use cases (e.g. full text 
search across all resources, search across multiple lists of the same 
type, e.g. different project areas) but perhaps these are not worth 
specifying in the core.  If no one has a compelling need for this, I am OK 
with dropping it.  Perhaps the more powerful types of query should be 
handled by an RDF index running full SPARQL.

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:
Arthur Ryman/Toronto/IBM at IBMCA
Cc:
oslc-core <oslc-core at open-services.net>, 
oslc-core-bounces at open-services.net
Date:
04/26/2010 03:09 PM
Subject:
Re: [oslc-core] Example of a self-subject query capability representation?

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
>>
>>
>>
>>
>
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