Why RDFa?

1
Why RDFa?
http//www.techpresentations.org/Why_RDFa?
Sergey Chernyshev some slides fromYaron Korens
Introduction to RDFa
SWNYC MeetupNovember 20th, 2008
2
Status

• W3C recommendation since October 14, 2008
  http//www.w3.org/TR/rdfa-syntax/
• First proposed in 2004

3
How RDFa works

• Joe Semantic's personal information
• I work as a programmer at MegaCorp - you can
  contact me at js_at_megacorp.com, or by phone at
  [phone].

4
HTML source

• lthtmlgt
• ltheadgt
• lttitlegtJoe Programmer's contact infolt/titlegt
• ltbase href"http//joeprogrammer.com/contact-i
  nfo.html" /gt
• lt/headgt
• ltbodygt
• lth1gtJoe Semantic's personal informationlt/h1gt
• ltpgtI work as a programmer at
• lta href"http//megacorp.com"gtMegaCorplt/agt
  -
• you can contact me at
• lta href"mailtojs_at_megacorp.com"gtjs_at_megaco
  rp.comlt/agt,
• or by phone at [phone].lt/pgt
• lt/bodygt
• lt/htmlgt

5
RDF / XML

• lt?xml version"1.0" encoding"UTF-8"?gt
• ltrdfRDF xmlnscontact"http//www.w3.org/2001/vca
  rd-rdf/3.0"gt
• ltrdfDescription rdfabout"http//joesemantic
  .com/contact-info.html"gt
• ltcontacttitle xmllang"en"gtprogrammerlt
  /contacttitlegt
• ltcontactorg rdfresource"http//megaco
  rp.com"/gt
• ltcontactemail rdfresource"js_at_megacorp
  .com"/gt
• ltcontacttel xmllang"en"gt(101)
  010-1010lt/contacttelgt
• lt/rdfDescriptiongt
• lt/rdfRDFgt

6

• Why not combine the two?

7

• lthtml xmlnscontact"http//www.w3.org/2001/vcard-
  rdf/3.0"gt
• ltheadgt
• lttitlegtJoe Semantic's personal
  informationlt/titlegt
• ltbase href"http//joesemantic.com/contact-inf
  o.html" /gt
• lt/headgt
• ltbodygt
• lth1gtJoe Semantic's personal informationlt/h1gt
• ltpgtI work as a
• ltspan propertycontacttitlegtprogrammerlt/spangt
• at
• lta rel"contactorg href"http//megacorp.com"gtM
  egaCorplt/agt
• - you can contact me at
• lta rel"contactemail href"mailtojs_at_megacorp.c
  om"gt
• js_at_megacorp.comlt/agt, or by phone at
• ltspan propertycontacttelgt(101)010-1010lt/spangt
  .
• lt/pgt
• lt/bodygt
• lt/htmlgt

8
Three main keywords in RDFa

• lta relpredicate hrefobjectgt...lt/agt
• ...defines a linked triple
• ltspan propertypredicategtobjectlt/spangt
• ...defines an unlinked triple (literal)
• ltspan aboutsubjectgt...lt/spangt
• ...creates a subject for triples

9
Creating subjects

• ...
• I'm currently reading
• ltspan abouturnISBN0-596-00027-8gt
• ltspan property"dctitle"gtProgramming
  Perllt/spangt
• by
• ltspan property"dccreator"gtLarry Walllt/spangt
• lt/spangt.
• ...

10
Easier to produce

• Much easier then RDF/XML or N-triples
• Almost as easy as Microformats
• Easy to integrate with existing publishing tools
  just change your HTML templates

11
Easy to use

• Probably first to be adopted by conventional
  search engines because they already crawl
  HTML(Yahoo! Search Monkey)
• Can be used with JavaScript (http//www.w3.org/200
  6/07/SWD/RDFa/impl/js/)
• Easy to integrate into current web page
  paradigm and workflow(CC license link at
  http//ben.adida.net/)

12
Links

• RDFa.infohttp//rdfa.info/
• RDFa primerhttp//www.w3.org/TR/xhtml-rdfa-primer
  /
• Yahoo! Search Monkeyhttp//developer.yahoo.com/se
  archmonkey
• shameless plug My Semantic Profilehttp//www.
  sergeychernyshev.com/profile/