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RDFa. Jelena Jovanovic. a large gap between what human and programs understand. RDFa Intro. RDFa = RDF in (HTML) Attributes The purpose to augment web pages with machine readable data to reduce the gap between what user and programs understand from a web page RDFa is tied to the data,
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RDFa JelenaJovanovic
RDFa Intro • RDFa = RDF in (HTML) Attributes • The purpose • to augment web pages with machine readable data • to reduce the gap between what user and programs understand from a web page • RDFa is tied to the data, so that rendered data can be copied and pasted along with its structure/metadata RDFa
<span about="http://farm1.static.flickr.com/...jpg"> <span property="title">Spiral Staircases</span> taken by <span property="creator">Paul Keleher</span>. <span property="geo:lat" content="42.359188" /> <span property="geo:long" content="-71.058291" /> </span> RDFa Spiral Staircase by Paul
<p> Ivan Herman knows Mark Birbeck and they have a meeting today. </p> <p about="http://www.w3.org/People/Ivan/#me" instanceof="foaf:Person"> <span property="foaf:name">Ivan Herman</span> knows Mark Birbeck and they have a meeting today. </p> <http://www.w3.org/People/Ivan/#me> rdf:type foaf:Person , foaf:name “Ivan Herman” . RDFa
<p> Ivan Herman knows Mark Birbeck and they have a meeting today. </p> <span about="http://www.w3.org/People/Ivan/#me" instanceof="foaf:Person"> <span property="foaf:name">Ivan Herman</span> knows <span rel="foaf:knows" resource="http://inter...blo.com/profile.html#"> Mark Birbeck </span> and they have a meeting today. </span> <http://www.w3.org/People/Ivan/#me> rdf:type foaf:Person , foaf:name “Ivan Herman” , foaf:knows <http://inter...blo.com/profile.html#> RDFa
Why do we need RDFa? • An event on a web page can be directly imported into a user's desktop calendar. • A license on a document can be detected so that the user is informed of his rights automatically. • A photo's creator, camera setting information, resolution, and topic can be published at the same time and as easily as the photo itself, enabling structured search and sharing. • … RDFa
Rich Snippets Search result for an ‘ordinary’ web page Search result for the same page powered with RDFa RDFa
Why is RDFa superior to other solutions? • Scalable • use any vocabularies you want • Mixable • mix and match any vocabulary you want in any way you want • W3C Standard • one parser will read any vocabulary; validation is trivial. • Globally Identifiable • give any thing on your page a URI and it becomes a "living" data point on the Web; easily addressable by anyone. • Turns Web page into stand-alone linked data clients • They becomequeryable like a database RDFa
Set of attributes provide by RDFa • about • determines what we are talking about • a URI specifying the resource that the metadata describes • rel& rev • specify a relationship with another resource • href, src, resource • specify a related resource • resource is the same as href, just not clickable • instanceof • sets the type of some resource RDFa
Set of attributes provide by RDFa • property • specifies a property of the resource being described • content • optional attribute that overrides the content of the elements when using the property attribute • datatype • optional attribute that specifies the datatype of some text • typeof • optional attribute that specifies the RDF type of the resource being described RDFa