Slides for lightning talk, providing short introduction to the Semantic Web, and outlining current initiatives to work with semantic web technologies within the Ruby on Rails framework.

1. and the Semantic Web
Ruby on Rails
& &
Nathalie Steinmetz
(http://nathaliesteinmetz.net)

2. 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: HTML
Semantics: none
?

3. Semantic Web? So…
2001
Tim 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.”

4. Two main goals:
1. Describe real world objects in a structured way
2. 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>

5. 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>

6. Semantic Web: Linked Data
Linked Open Data Cloud:Google, Microsoft,
Facebook:
Bing
Snapshot
Google
Knowledge
Graph
Facebook
Graph Search

7. 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-unit
test "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

8. 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/