Presentation Overview
- RDF & Background
- FOAF - The Giant Global Graph
- Why Linked Data is cool
- Some Tools
- Building a linked FOAF Person (some SPARQL PHP and APACHE FUN)
DISCLAIMER - I am no elitist, any old RDF is better than nothing
- I don't know much about the Linked Data TM
- But ...
- RDF is useful
- HTTP resolvable RDF is even more useful
- Publish RDF, and put it on the web!
- Some examples of Scruffy RDF
- Bestbuy (GoodRelations)
- Tesco (GoodRelations)
- myspace (FOAFie type data)
- Dirty very true, but they are all big players
- And the commands to grab their data
Semantic Web / The Web of Data 1/2
- The Resource Description Framework (RDF) -triples.
MIME-types:
- n3 text/rdf+n3
- ntriples text/plain
- turtle application/x-turtle
- RDF-XML application/rdf+xml
- Shared Conceptualisations/domain models/ontologies : OWL
- A Cat is_a Mammal, Mammals give birth, ...
- Person is an Agent, Agents interact with their environment, A Person can have friends, A person has an age of type integer, with a cardinality of > 0
Semantic Web / The Web of Data 2/2
Uniform Resource Identifiers (URI)
Who knows what a URI is?
- A URI is a compact sequence of characters that identifies an abstract concept
or a physical resource - RFC3986
- foo://bar.com:8001/boo/x?something=value#fragment
- \___/\___________/\____/ \_____________/ \______/
- scheme authority path query fragment
- URIs are NOT merely URLs!
- And I should stress that cool ones don't change
- http://
- mailto:
- tag:
- file://
- isbn:
- urn://
- ...
RDF isn't that bad ...
- RDF is not simply a flavour of XML, but it can be serialised in XML, but it is very ugly
<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/">
<foaf:PersonalProfileDocument rdf:about="">
<foaf:primaryTopic rdf:resource="http://mmt.me.uk/foaf.rdf#mischa"/>
</foaf:PersonalProfileDocument>
<foaf:Person rdf:ID="mischa">
<foaf:homepage rdf:resource="http://mmt.me.uk/"/>
</foaf:Person>
</rdf:RDF>
- It can be serialised in other ways to make it easier to read ...
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
<> a foaf:PersonalProfileDocument ;
foaf:primaryTopic <#mischa> .
<#mischa> a foaf:Person ;
foaf:homepage <http://mmt.me.uk/> .
- It can even more verbose:
<http://mmt.me.uk/foaf.rdf> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/PersonalProfileDocument> .
<http://mmt.me.uk/foaf.rdf> <http://xmlns.com/foaf/0.1/primaryTopic> <http://mmt.me.uk/foaf.rdf#mischa> .
<http://mmt.me.uk/foaf.rdf#mischa> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> .
<http://mmt.me.uk/foaf.rdf#mischa> <http://xmlns.com/foaf/0.1/homepage> <http://mmt.me.uk/> .
So what does all of this mean?
Quads
So, all this called of RDF and triples, what are these quads which people talk about?
- Provenance information
- The fourth triple or where the RDF graph has come from
- Bunch of different formats
...
My Favourite Picture ... Diagram
- My favourite TimBL picture :
So why should I bothered with Linked Data
- Because everyone else is doing it ;) (not good enough)
- Fluffy open reasons, non-proprietary
- Because you can't query (e.g. the awesome SPARQL) a csv file or some other arbitrary format
Because you can't SPARQL a csv file or some arbitrary format
- Or you can use a shiny command line tool, like roqet, which comes with librasqal
roqet -r simple --exec "select * from <http://mmt.me.uk/foaf.rdf> where {<http://mmt.me.uk/foaf.rdf> ?a ?b}"
FOAF : The Friend-Of-A-Friend Ontology
- 'The Friend of a Friend (FOAF) project began early in 2000 as an "experimental linked information project", created by Dan Brickley and Libby Miller.'
- RDF : http://xmlns.com/foaf/0.1/
- HTML : http://www.foaf-project.org/
- FOAF makes it possible for people to build large scale, decentralised, open social networks that are controlled by individual users.
- Sites such as : LiveJournal, hi5, vox, friendfeed?, google???,...
- Reflectors : twitter, flickr, lastfm, delicious, ...
The FOAF Landscape as per Q1 2009
Perhaps Controversial?
- The biggest part of the Linked Data Cloud is the FOAF bubble
- The most interesting part of the LOD is the FOAF bit, which makes up the Giant Global Graph (GGG)
- A truly portable social network
FOAF Validator
- Validators are good, and am not talking about RDF (syntax) validators, more along the lines of ontology/vocabulary validators
- The W3C's RDF validator is definitely a good thing
- We should be building more of these validators, GoodRelation's could definitely do with one
FOAF IFPs
- Linked Data promotes URIs and web resovable ones.
- But RDF/OWL has a concept of an Inverse Functional Property (IFP)
- List them here ...
- This allows for us to write RDF about a thing which we don't know their http:// URI for
- Whilst allowing for the item to be giving a Unique Identifier (or a URI;)
- Caters for searching on FOAF IFPs (what
is an IFP?)
Overview (a Steve-ism)
- HTML view of a FOAF PersonalProfileDocument
- Includes a list of friends
- Includes a view of who claims to know the given foaf:Person
- RAP
- AJAR(ish)
- SPARQL
- SPARQL-PROTOCOL to 4-store
- A Foaf Editor which allows you to :
- Search for a FOAF file
- Build and store a FOAF file
- Edit their own existing FOAF file
- Manage privacy and permissions
- Provision of a service that allows people to search and browse millions of FOAF files in a user friendly way
- Edit / Store Personal Info in both a Public and Private Manner
- Get your location via GUI
- RAP
- AJAR(ish)
- SPARQL
- SPARQL-PROTOCOL to 4-store
- A Foaf Editor which allows you to :
- Search for a FOAF file
- Build and store a FOAF file
- Edit their own existing FOAF file
- Manage privacy and permissions
- Provision of a service that allows people to search and browse millions of FOAF files in a user friendly way
- Edit / Store Personal Info in both a Public and Private Manner
- Get your location via GUI
- Write to WebDAV, save the file to your machine, ...
- Get the RDF out of the FOAF builder
- Get your own FOAF OAuth endpoint with your OpenID URI
- Allows for private FOAF data to be stored and retrieved from an OAuth endpoint
- Entering a unique identifier for a foaf:Person (i.e. email address, mbox sha1sum, homepage, weblog, or a FOA
F URI) will return FOAF RDF listing foaf:Persons which the identifier claims to know.
- Parameters : path and ifp
- Example 1: http://foaf.qdos.com/forwa
rd?path=http://danbri.org/&ifp
<http://users.ecs.soton.ac.uk/nrs/foaf.rdf#me>
a foaf:Person ;
foaf:knows [
a foaf:Person ;
foaf:mbox_sha1sum "965c47c5a70db7407210cef6e4e6f5374a525c5c" ;
foaf:name "Tim Berners-Lee"
], [
a foaf:Person ;
foaf:mbox_sha1sum "26a374ad4de937252c044f7dd45aa48ecbdb4f16" ;
foaf:name "Steve Harris"
], [
a foaf:Person ;
foaf:mbox_sha1sum "28339a9a36ee4e330da9613958efb89e2961c6cb" ;
foaf:name "Nick Gibbins"
], [
a foaf:Person ;
foaf:mbox_sha1sum "ca2d238d1ade1efb7128874e99e84fdef5a3c447" ;
foaf:name "Tom Heath"
] .
- Example 2: http://foaf.qdos.com/forward?path=http://moustaki.org/foaf.rdf%23moustaki
<http://tomheath.com/id/me> a foaf:Person .
<http://nxg.me.uk/norman>
a foaf:Person ;
foaf:homepage <http://nxg.me.uk>, <http://www.astro.gla.ac.uk/users/norman/> ;
foaf:knows <http://tomheath.com/id/me> ;
foaf:mbox_sha1sum "0254b43a4c00a8c5eb9093d9820353640ee02786", "14f2d3a469303d0faca13f73064845ddda4d2dbd",
"58a587e433b1e0c22aa026eeee7703ffcee6262c","bfeee75c2025815392014a95cfd4b6aad117c07f",
"84612b3540a255bb11de3db579e02533ff2631c5", "baa162e14a20b3fafbccbf0fceaa1159a3a042d1",
"c9994fd3713561d0d9a468cd30c11a0f3cb3055a", "e6578555a8108ea83ee7f1d60556e63fd83bcc5e" ;
foaf:name "Norman Gray" .
[]
a foaf:Person ;
foaf:homepage <http://kmi.open.ac.uk/people/mikele> ;
foaf:knows <http://tomheath.com/id/me> ;
foaf:mbox_sha1sum "97ddc048d1a7df5e6fcb8f530777896a395d3dc1" ;
foaf:name "Michele Pasin" .
<http://www.aelius.com/njh#me>
a foaf:Person ;
foaf:homepage <http://www.aelius.com/njh/> ;
foaf:knows <http://tomheath.com/id/me> ;
foaf:mbox_sha1sum "3f361af12a473b48852819e3ff9153783149a26a", "a8476e8096db2bde20a734c8446bb3d60befea2b" ;
foaf:name "Nicholas J Humfrey" .
So how is this useful..?
- Try adding the following triples to your foaf file:
<#me> rdfs:seeAlso <http://foaf.qdos.com/forward?path=http://foo.com/blog&ifp>
<#me> rdfs:seeAlso <http://foaf.qdos.com/reverse?path=http://foo.com/blog&ifp>
<#me> rdfs:seeAlso <http://foaf.qdos.com/sameas?path=http://foo.com/blog&ifp>
!-- Social Verification Demo -->
