and the Semantic Web

Ruby on Rails

& &

Nathalie Steinmetz (http://nathaliesteinmetz.net)

Semantic Web? Wait, what’s that?

I love Ruby on Rails

I Ruby on Rails

vs.

Syntax vs. semantics of a sentence:

On the Web:

codefellows.org

Syntax: HTMLSemantics: none

?

Semantic Web? So…

2001Tim Berners-Lee

A Web of data:

“The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries.”

Two main goals:1. Describe real world objects in a structured way2. Integrate and combine data from different sources

Semantic Web: RDF & vocabularies

Main language: RDF

Nathalie Ruby on Rails

likes

Subject Predicate Object

Use existing vocabularies:

FOAF

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:ex="http://example.org/vocabulary#"> <ex:Nathalie> <ex:likes><ex:Ruby_on_Rails>

</rdf:RDF>

Semantic Web: in action

How to markup web pages:

Schema.org – recognized by Bing, Google, Yahoo and Yandex:

RDFa:Embedding RDF into HTML

JSON-LD:Lightweight Linked Data format based on JSON

Microdata:Embedding machine-readable data into HTML

<div> <h1>Avatar</h1> <span>Director: James Cameron (born August 16, 1954)</span> <span>Science fiction</span> <a href="../movies/avatar-theatrical-trailer.html">Trailer</a> </div>

<div itemscope itemtype ="http://schema.org/Movie"> <h1 itemprop="name“ Avatar</h1> <div itemprop="director" itemscope itemtype="http://schema.org/Person"> Director: <span itemprop="name">James Cameron</span> (born <span itemprop="birthDate">August 16, 1954)</span> </div> <span itemprop="genre">Science fiction</span> <a href="../movies/avatar-theatrical-trailer.html" itemprop="trailer">Trailer</a> </div>

Semantic Web: Linked Data

Linked Open Data Cloud:Google, Microsoft, Facebook:

Bing Snapshot

Google Knowledge Graph

Facebook Graph Search

Semantic Web on Rails

Ruby RDF Project: ruby-rdf.github.io

Automated testing of HTML5 microdata:

Contains numerous gems supporting Linked Data and Semantic Web programming:

• gem ‘rdf’• gem ‘rdf-rdfa’• gem ‘rdf-microdata’• gem ‘json-ld’• rack middleware ‘rack-sparql’• rack middleware ‘rack-sesame’

• gem linkeddata (combination of several gems)

Ruby library for extracting HTML5 microdata:• gem ‘microdata’

Integration tests using test-unittest "the top level item is a schema.org/Person" do assert_equal ['http://schema.org/Person'],

@items.first.type end test "the Person should have a name, url, and job title" do person = @items.first assert_equal ['Jason Ronallo'], person.properties['name'] assert_equal ['http://twitter.com/ronallo'],

person.properties['url'] assert_equal ['Ass. Head of Digital Library Initiatives'],

person.properties['jobTitle'] end

Questions?

More info at:

Semantic Web: http://www.w3.org/standards/semanticweb/

RDF: http://www.w3.org/standards/techs/rdf#w3c_all

RDFa: http://rdfa.info/

JSON-LD: http://json-ld.org/

RDF.rb: http://rdf.rubyforge.org/

Ruby RDF project: http://ruby-rdf.github.io/

HTML5 microdata test: http://jronallo.github.io/blog/automated-testing-of-html5-microdata-in-rails/