INF3580/4580 { Semantic Technologies { Spring 2016 Lecture 15: RDFa Martin Giese 30th May 2016 Department of University of Informatics Oslo Repetition 18 June: Guest lecture, Lars Marius Garshol 25 May: no lecture (Whit Monday) 1st June is reserved for \Repetition" No fixed lecture material You, the students, say what you want to hear Let me know in time, so I'm prepared. Drop a mail to [email protected] until 18th May INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 2 / 29 Today's Plan 1 Reminder 2 Linking RDF to HTML 3 RDFa 4 Conclusion INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 3 / 29 Reminder Outline 1 Reminder 2 Linking RDF to HTML 3 RDFa 4 Conclusion INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 4 / 29 FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds for instance dbpedia.org, dblp, and others In RDF files, downloadable with HTTP, FTP, etc. Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 for instance dbpedia.org, dblp, and others FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 for instance dbpedia.org, dblp, and others data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 for instance dbpedia.org, dblp, and others In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles data files from dbpedia.org, geonames, etc. INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 for instance dbpedia.org, dblp, and others Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 for instance dbpedia.org, dblp, and others As metadata in PDF/A files As data model behind SPARQL query endpoints Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 for instance dbpedia.org, dblp, and others As data model behind SPARQL query endpoints Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 for instance dbpedia.org, dblp, and others Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 Embedded in HTML, as RDFa Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints for instance dbpedia.org, dblp, and others INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 Reminder RDF on the Web RDF data exists in many forms: In RDF files, downloadable with HTTP, FTP, etc. FOAF profiles data files from dbpedia.org, geonames, etc. In RSS 1.0 feeds Published using LOD principles (hash/slash namespaces) As metadata in PDF/A files As data model behind SPARQL query endpoints for instance dbpedia.org, dblp, and others Embedded in HTML, as RDFa INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 5 / 29 Linking RDF to HTML Outline 1 Reminder 2 Linking RDF to HTML 3 RDFa 4 Conclusion INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 6 / 29 Linking RDF to HTML The Problem The HTML web contains lots of human-readable information How can clients discover the location of corresponding machine-readable information? −!? INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 7 / 29 Not recommended: Does not fit HTML or XHTML DTDs No satisfactory solution, due to flexible RDF vocabulary B.t.w. there is a metadata element in SVG for this! Linking RDF to HTML Embedding RDF/XML in (X)HTML First idea: Embed RDF/XML in HTML or XHTML: <html> <head> <title>My Homepage</title> <rdf:RDF> <rdf:Description rdf:about="#me"> <foaf:name>Martin Giese</foaf:name> ... INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 8 / 29 Does not fit HTML or XHTML DTDs No satisfactory solution, due to flexible RDF vocabulary B.t.w. there is a metadata element in SVG for this! Linking RDF to HTML Embedding RDF/XML in (X)HTML First idea: Embed RDF/XML in HTML or XHTML: <html> <head> <title>My Homepage</title> <rdf:RDF> <rdf:Description rdf:about="#me"> <foaf:name>Martin Giese</foaf:name> ... Not recommended: INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 8 / 29 No satisfactory solution, due to flexible RDF vocabulary B.t.w. there is a metadata element in SVG for this! Linking RDF to HTML Embedding RDF/XML in (X)HTML First idea: Embed RDF/XML in HTML or XHTML: <html> <head> <title>My Homepage</title> <rdf:RDF> <rdf:Description rdf:about="#me"> <foaf:name>Martin Giese</foaf:name> ... Not recommended: Does not fit HTML or XHTML DTDs INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 8 / 29 B.t.w. there is a metadata element in SVG for this! Linking RDF to HTML Embedding RDF/XML in (X)HTML First idea: Embed RDF/XML in HTML or XHTML: <html> <head> <title>My Homepage</title> <rdf:RDF> <rdf:Description rdf:about="#me"> <foaf:name>Martin Giese</foaf:name> ... Not recommended: Does not fit HTML or XHTML DTDs No satisfactory solution, due to flexible RDF vocabulary INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 8 / 29 Linking RDF to HTML Embedding RDF/XML in (X)HTML First idea: Embed RDF/XML in HTML or XHTML: <html> <head> <title>My Homepage</title> <rdf:RDF> <rdf:Description rdf:about="#me"> <foaf:name>Martin Giese</foaf:name> ... Not recommended: Does not fit HTML or XHTML DTDs No satisfactory solution, due to flexible RDF vocabulary B.t.w. there is a metadata element in SVG for this! INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 8 / 29 CSS style sheets Alternative languages Next, previous, index, etc. rel { the kind of relation type { the media type of the related document href { the URL of the other document title { the title of the other document (and some more) relate a document to other documents Can contain attributes: E.g. a style sheet: <html> <head> <title>My Homepage</title> <link rel="stylesheet" type="text/css" href="style.css"> Linking RDF to HTML HTML LINK elements LINK may occur inside HTML HEAD elements INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 rel { the kind of relation type { the media type of the related document href { the URL of the other document title { the title of the other document (and some more) CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes: E.g. a style sheet: <html> <head> <title>My Homepage</title> <link rel="stylesheet" type="text/css" href="style.css"> Linking RDF to HTML HTML LINK elements LINK may occur inside HTML HEAD elements relate a document to other documents INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 rel { the kind of relation type { the media type of the related document href { the URL of the other document title { the title of the other document (and some more) Alternative languages Next, previous, index, etc. Can contain attributes: E.g. a style sheet: <html> <head> <title>My Homepage</title> <link rel="stylesheet" type="text/css" href="style.css"> Linking RDF to HTML HTML LINK elements LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 rel { the kind of relation type { the media type of the related document href { the URL of the other document title { the title of the other document (and some more) Next, previous, index, etc.