Re: Facebook Linked Data

[Kingsley Idehen]

On 9/26/11 11:05 AM, Alvaro Graves wrote:

Hi Sebastian,



http://www.w3.org/2001/tag/issues.html#httpRange-14

AFAIK it's not a bug, but a feature :). This is done to comply with the httpRange-14 issue (i.e., you can't retrieve a person through HTTP but you can retrieve a document _about_ a person through HTTP). Since a person and a document about a person are different entities, they should have different URIs.

2. structured Data Representation via an EAV/SPO based directed graph
3. a Distinct Data Access Address (URL).





Links:

In alternative lingo, its a feature that results in a fine grained data object that's endowed with: 1. a Distinct and Unambiguous Identifier (de-referencable HTTP URI based Name) We don't have to bring httpRange-14 and its timeless imbroglio into every conversation re. Linked Data :-) This is just about the basic principle of Object Identity [1] exploited via ingenious useof de-referencable URIs. 1. http://www.cs.cmu.edu/afs/cs.cmu.edu/user/clamen/OODBMS/Manifesto/htManifesto/node4.html -- Object Identity

Kingsley

----
Alvaro Graves

On Mon, Sep 26, 2011 at 7:46 AM, Sebastian Schaffert <sebastian.schaff...@salzburgresearch.at <mailto:sebastian.schaff...@salzburgresearch.at>> wrote:

    Dear Jesse,

    Thanks for the effort! I am just experimenting with this. If I
    request my own Vanity URL

    http://graph.facebook.com/sebastian.schaffert

    The data I get back is:

    @prefix rdf: <http://www.w3.org/1999/02/22-df-syntax-ns#> .
    @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
    @prefix owl: <http://www.w3.org/2002/07/owl#> .
    @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
    @prefix api: <tag:graph.facebook.com
    <http://graph.facebook.com>,2011:/> .
    @prefix og: <http://ogp.me/ns#> .
    @prefix fb: <http://ogp.me/ns/fb#> .
    @prefix : <http://graph.facebook.com/schema/~/
    <http://graph.facebook.com/schema/%7E/>> .
    @prefix user: <http://graph.facebook.com/schema/user#> .
    </561666514#>
           user:id "561666514" ;
           user:name "Sebastian Schaffert" ;
           user:first_name "Sebastian" ;
           user:last_name "Schaffert" ;
           user:link <http://www.facebook.com/sebastian.schaffert>



    Now the problem I see here is that the URI I requested is not the
    same URI as used in the subject of the RDF triples. Same holds btw
    if I request the data using the ID including "#". Which is bad in
    our case because we filter out triples that do not fulfill this
    condition to avoid importing "invalid" data.

    Also, the data should IMHO contain a @base statement defining the
    base for the </561666514#>, because when importing the data the
    original URI is sometimes no longer available.

    Lastly, the returned data does not contain the trailing "."
    required by turtle (see
    http://www.w3.org/TeamSubmission/turtle/#sec-grammar-grammar).

    Are there plans to fix this? For me, the more readable data would
    look like this:

    @prefix rdf: <http://www.w3.org/1999/02/22-df-syntax-ns#> .
    @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
    @prefix owl: <http://www.w3.org/2002/07/owl#> .
    @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
    @prefix api: <tag:graph.facebook.com
    <http://graph.facebook.com>,2011:/> .
    @prefix og: <http://ogp.me/ns#> .
    @prefix fb: <http://ogp.me/ns/fb#> .
    @prefix user: <http://graph.facebook.com/schema/user#> .
    <http://graph.facebook.com/sebastian.schaffert>
           user:id "561666514" ;
           user:name "Sebastian Schaffert" ;
           user:first_name "Sebastian" ;
           user:last_name "Schaffert" ;
           user:link <http://www.facebook.com/sebastian.schaffert>



    Am 23.09.2011 um 14:09 schrieb Jesse Weaver:

    > APOLOGIES FOR CROSS-POSTING
    >
    > I would like to bring to subscribers' attention that Facebook now
    > supports RDF with Linked Data URIs from its Graph API.  The RDF
    is in
    > Turtle syntax, and all of the HTTP(S) URIs in the RDF are
    dereferenceable
    > in accordance with httpRange-14.  Please take some time to check
    it out.
    >
    > If you have a vanity URL (mine is jesserweaver), you can get RDF
    about you:
    >
    > curl -H 'Accept: text/turtle' http://graph.facebook.com/<vanity-url>
    > curl -H 'Accept: text/turtle' http://graph.facebook.com/jesserweaver
    > If you don't have a vanity URL but know your Facebook ID, you
    can use
    > that instead (which is actually the fundamental method).
    >
    > curl -H 'Accept: text/turtle'
    http://graph.facebook.com/<facebook-id>
    > curl -H 'Accept: text/turtle' http://graph.facebook.com/1340421292
    >> From there, try dereferencing URIs in the Turtle.  Have fun!
    >
    > Jesse Weaver
    > Ph.D. Student, Patroon Fellow
    > Tetherless World Constellation
    > Rensselaer Polytechnic Institute
    > http://www.cs.rpi.edu/~weavej3/ <http://www.cs.rpi.edu/%7Eweavej3/>
    >
    >
    >
    >
    >

    Sebastian
    --
    | Dr. Sebastian Schaffert sebastian.schaff...@salzburgresearch.at
    <mailto:sebastian.schaff...@salzburgresearch.at>
    | Salzburg Research Forschungsgesellschaft
    http://www.salzburgresearch.at
    | Head of Knowledge and Media Technologies Group +43 662 2288 423
    <tel:%2B43%20662%202288%20423>
    | Jakob-Haringer Strasse 5/II
    | A-5020 Salzburg

--

Regards,

Kingsley Idehen 
President&  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen

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