Building Linked Data Apps for the

iPhone

11/12 juni HTML Hackathon

Henk Jurriens

www.ihenk.com

www.twitter.com/henkjurriens

Linked Data

Developing for iPhone

Lodsy

Linked Open DataLinked Open Data

Data sets•DBPedia

•GeoName

• FOAF

8-10-2007

28-2-2008

5-3-2009

14-7-2009

"a term used to describe a recommended best practice for exposing, sharing, and

connecting pieces of data, information, and knowledge on the Semantic Web"

Linked Data Principles

1.Use URI as names for things

2.Use HTTP URIs so that people can look up those names

3.When someone looks up a URI, provide useful information, using the standards (RDF, SPARQL)

4.Include links to other URIs, so that they can discover more things

Include links to other URIs, so that they can discover more things

Technology stack

URIURIURIURI HTTPHTTPHTTPHTTP

RDF, RDF/XML, RDF SchemaRDF, RDF/XML, RDF SchemaRDF, RDF/XML, RDF SchemaRDF, RDF/XML, RDF Schema

RDFaRDFaRDFaRDFa GRDDLGRDDLGRDDLGRDDL SPARQLSPARQLSPARQLSPARQL

Resource Description Framework

restaurantrestaurantrestaurantrestaurant ““OstermalmshallenOstermalmshallen””

““OstermalmshallenOstermalmshallen””

title

subjectsubjectsubjectsubject valuevaluevaluevalue

property

subject has a property with “value” (s,p,v)

id title description type

1Ostermalmshall

enA very nice...

market

... ... ... ...

““OstermalmshallenOstermalmshallen””

““OstermalmshallenOstermalmshallen””

title

““A very nice ...”A very nice ...”““A very nice ...”A very nice ...”

marketmarketmarketmarket

description

restaurantrestaurantrestaurantrestaurant

type

““OstermalmshallenOstermalmshallen””

““OstermalmshallenOstermalmshallen””

title

““A very nice ...”A very nice ...”““A very nice ...”A very nice ...”

marketmarketmarketmarket

description

type

restaurantrestaurantrestaurantrestaurant

owner

JurriensJurriensJurriensJurriens

personpersonpersonpersonname

RDF names things with URIs

<<http://www.ostermalmshallen.se

>>

<<http://www.ostermalmshallen.se

>>““OstermalmshallenOstermalmshallen

””““OstermalmshallenOstermalmshallen

””

<http://purl.org/dc/elements/1.1/title>

•Dublin Core

• FOAF

•Geo

• http://www.schemaweb.info

Writing down graphs

<http://www.ostermalmshallen.se> <http://purl.org/dc/elements/1.1/title

> "Ostermalm Food Hall" .

SPARQL

•Prefix declarations

•Dataset definition

•Result clause

•Query pattern

•Queri modifiers

# prefix declarations

PREFIX foo: <http://example.com/resources/>

...

# dataset definition

FROM ...

# result clause

SELECT ...

# query pattern

WHERE {

...

}

# query modifiers

ORDER BY ...

SPARQL endpoints

•Generic

•Specific

Result of SPARQL queries

•XML

•JSON

•RDF (RDF/XML, N3)

@prefix foaf: <http://xmlsn.com/foaf/0.1/> .

@prefix dc: <http://purl.org/dc/elements/1.1/> .

@prefix geo: <http://www.w3.org/2003/01/geo/> .

<http://www.ostermalmshallen.se> <dc:title> "Ostermalm Food Hall" .

<http://www.ostermalmshallen.se> <foaf:img> <http://flickr.com/7a_b.jpg> .

<http://www.ostermalmshallen.se> <geo:wgs84_pos#lat> "59.332788" .

<http://www.ostermalmshallen.se> <geo:wgs84_pos#long> "18.064488" .

PREFIX dc: <http://purl.org/dc/elements/1.1/>.

SELECT ?title

WHERE {

?restaurant dc:title ?title .

}

Good news

more

Developing for iPhone

Technologies

Objective C

HTMLiPhone SDK

REST

HTML 5

CSS3

Google Maps API

• iProcessing.js

• jQTouch

Libraries

Lodsy

ConceptsFacets

LodsyLodsy LODLOD

Triple Triple storestoreTriple Triple storestore

Architecture

SPARQL

Facets

Views

SPARQL

q= <http://www.ihenk.com/henkjurriens> ?p ?v

q = ?s <http://purl.org/dc/elements/1.1/title> ?v

q = ?s <http://purl.org/dc/elements/1.1/title> ?v |

?s <http://xmlns.com/foaf/0.1/img> ?v

Facets

Facet

Name Property Type

Title<http://purl.org/dc/elements/

1.1/title> String

Email<http://xmlns.com/foaf/0.1/

mbox> Email

... ... ...

Views

rdfView

mapView

mapDetail

Demo

Future work

One more thing

Questions?