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:
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:
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:
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:
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:
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:
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:
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:
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. Can contain attributes:
E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages
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)
Can contain attributes:
E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc.
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) E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 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) E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes: rel – the kind of relation
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 href – the URL of the other document title – the title of the other document (and some more) E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes: rel – the kind of relation type – the media type of the related document
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 title – the title of the other document (and some more) E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes: rel – the kind of relation type – the media type of the related document href – the URL of the other document
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 (and some more) E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes: 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
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 E.g. a style sheet:
Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes: 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)
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 9 / 29 Linking RDF to HTML HTML LINK elements
LINK may occur inside HTML HEAD elements relate a document to other documents CSS style sheets Alternative languages Next, previous, index, etc. Can contain attributes: 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) E.g. a style sheet:
Also: rel="meta"
Turtle: type="text/turtle; charset=UTF-8" Various web browser plugins exist to detect these LINKs
Linking RDF to HTML LINKing to RDF
To link to an RDF representation: xml" title="RDF/XML version" href="http://dbpedia.org/data/Oslo.xml">
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 10 / 29 Note: difference between meta-data and alternative representation Turtle: type="text/turtle; charset=UTF-8" Various web browser plugins exist to detect these LINKs
Linking RDF to HTML LINKing to RDF
To link to an RDF representation: Also: rel="meta"
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 10 / 29 Turtle: type="text/turtle; charset=UTF-8" Various web browser plugins exist to detect these LINKs
Linking RDF to HTML LINKing to RDF
To link to an RDF representation: Also: rel="meta" Note: difference between meta-data and alternative representation
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 10 / 29 Various web browser plugins exist to detect these LINKs
Linking RDF to HTML LINKing to RDF
To link to an RDF representation: Also: rel="meta" Note: difference between meta-data and alternative representation Turtle: type="text/turtle; charset=UTF-8"
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 10 / 29 Linking RDF to HTML LINKing to RDF
To link to an RDF representation: Also: rel="meta" Note: difference between meta-data and alternative representation Turtle: type="text/turtle; charset=UTF-8" Various web browser plugins exist to detect these LINKs
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 10 / 29 can be sent also with non-HTML data requires only HEAD request
Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
Linking RDF to HTML HTTP Link: response headers
Problems with elements:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 can be sent also with non-HTML data requires only HEAD request
Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc.
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 can be sent also with non-HTML data requires only HEAD request
Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK.
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 can be sent also with non-HTML data requires only HEAD request
Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header.
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 can be sent also with non-HTML data requires only HEAD request
Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 can be sent also with non-HTML data requires only HEAD request
Same information as in LINK HTML element, but as HTTP header: Link:
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 can be sent also with non-HTML data requires only HEAD request
Advantages:
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 can be sent also with non-HTML data requires only HEAD request
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 requires only HEAD request
Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 Linking RDF to HTML HTTP Link: response headers
Problems with elements: Only works with HTML data, not PDF, Images, etc. Need to download HTML content and search LINK. Idea: put information in HTTP response header. Non-standardized proposal, originally by Berners-Lee, 1992 Generated by a few servers, recognized by a few clients Same information as in LINK HTML element, but as HTTP header: Link:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 11 / 29 RDFa Outline
1 Reminder
2 Linking RDF to HTML
3 RDFa
4 Conclusion
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 12 / 29 From the RDFa specification (http://www.w3.org/TR/rdfa-syntax/) The aim of RDFa is to allow a single RDF graph to be carried in various types of document mark-up.
Use a different “serialization” that blends well with (X)HTML!
XHTML in spec., but works with HTML and other XML RDFa adds a fixed set of attributes to (X)HTML Document type:
RDFa Once More: Embedding RDF in (X)HTML
Directly embedding RDF/XML in (X)HTML does not work well
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 13 / 29 From the RDFa specification (http://www.w3.org/TR/rdfa-syntax/) The aim of RDFa is to allow a single RDF graph to be carried in various types of document mark-up.
XHTML in spec., but works with HTML and other XML RDFa adds a fixed set of attributes to (X)HTML Document type:
RDFa Once More: Embedding RDF in (X)HTML
Directly embedding RDF/XML in (X)HTML does not work well Use a different “serialization” that blends well with (X)HTML!
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 13 / 29 XHTML in spec., but works with HTML and other XML RDFa adds a fixed set of attributes to (X)HTML Document type:
RDFa Once More: Embedding RDF in (X)HTML
Directly embedding RDF/XML in (X)HTML does not work well Use a different “serialization” that blends well with (X)HTML!
From the RDFa specification (http://www.w3.org/TR/rdfa-syntax/) The aim of RDFa is to allow a single RDF graph to be carried in various types of document mark-up.
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 13 / 29 RDFa adds a fixed set of attributes to (X)HTML Document type:
RDFa Once More: Embedding RDF in (X)HTML
Directly embedding RDF/XML in (X)HTML does not work well Use a different “serialization” that blends well with (X)HTML!
From the RDFa specification (http://www.w3.org/TR/rdfa-syntax/) The aim of RDFa is to allow a single RDF graph to be carried in various types of document mark-up.
XHTML in spec., but works with HTML and other XML
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 13 / 29 Document type:
RDFa Once More: Embedding RDF in (X)HTML
Directly embedding RDF/XML in (X)HTML does not work well Use a different “serialization” that blends well with (X)HTML!
From the RDFa specification (http://www.w3.org/TR/rdfa-syntax/) The aim of RDFa is to allow a single RDF graph to be carried in various types of document mark-up.
XHTML in spec., but works with HTML and other XML RDFa adds a fixed set of attributes to (X)HTML
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 13 / 29 RDFa Once More: Embedding RDF in (X)HTML
Directly embedding RDF/XML in (X)HTML does not work well Use a different “serialization” that blends well with (X)HTML!
From the RDFa specification (http://www.w3.org/TR/rdfa-syntax/) The aim of RDFa is to allow a single RDF graph to be carried in various types of document mark-up.
XHTML in spec., but works with HTML and other XML RDFa adds a fixed set of attributes to (X)HTML Document type:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 13 / 29 RDFa RDFa Processing
Web browsers ignore RDFa attributes RDFa processors extract a single RDF graph from a document
XHTML+RDFa
Web browser RDFa processor
Web page RDF graph
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 14 / 29 hyper-links (href) textual content RDFa attributes can appear in (almost) any element As the XHTML is processed, there is always a “current subject” that generated triples refer to The current subject starts as the base URI of the document, but can change on the way
RDFa RDFa Concepts
RDFa adds semantic annotations to
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 15 / 29 textual content RDFa attributes can appear in (almost) any element As the XHTML is processed, there is always a “current subject” that generated triples refer to The current subject starts as the base URI of the document, but can change on the way
RDFa RDFa Concepts
RDFa adds semantic annotations to hyper-links (href)
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 15 / 29 RDFa attributes can appear in (almost) any element As the XHTML is processed, there is always a “current subject” that generated triples refer to The current subject starts as the base URI of the document, but can change on the way
RDFa RDFa Concepts
RDFa adds semantic annotations to hyper-links (href) textual content
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 15 / 29 As the XHTML is processed, there is always a “current subject” that generated triples refer to The current subject starts as the base URI of the document, but can change on the way
RDFa RDFa Concepts
RDFa adds semantic annotations to hyper-links (href) textual content RDFa attributes can appear in (almost) any element
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 15 / 29 The current subject starts as the base URI of the document, but can change on the way
RDFa RDFa Concepts
RDFa adds semantic annotations to hyper-links (href) textual content RDFa attributes can appear in (almost) any element As the XHTML is processed, there is always a “current subject” that generated triples refer to
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 15 / 29 RDFa RDFa Concepts
RDFa adds semantic annotations to hyper-links (href) textual content RDFa attributes can appear in (almost) any element As the XHTML is processed, there is always a “current subject” that generated triples refer to The current subject starts as the base URI of the document, but can change on the way
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 15 / 29 Meaning of name and rel informal Only a few values defined by the standard
RDFa Reminder: (X)HTML Meta and Link
Links and metadata in HTML header:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 16 / 29 Only a few values defined by the standard
RDFa Reminder: (X)HTML Meta and Link
Links and metadata in HTML header:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 16 / 29 RDFa Reminder: (X)HTML Meta and Link
Links and metadata in HTML header:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 16 / 29 Extracted triples: (<> is base URI!) <> dc:creator "Martin Giese" . <> foaf:topic
RDFa RDFa property and rel
“semantic” meta and link in RDFa:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 17 / 29 RDFa RDFa property and rel
“semantic” meta and link in RDFa:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 17 / 29 Extracted triple: <> cc:license
RDFa Attribute rel on A elements
Any hyper-link can be given a “meaning”: This document is licensed under a Creative Commons License .
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 18 / 29 Can use rev instead of rel to swap subject and object: Made by me. Extracted triple:
RDFa Attribute rel on A elements
Any hyper-link can be given a “meaning”: This document is licensed under a Creative Commons License . Extracted triple: <> cc:license
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 18 / 29 Extracted triple:
RDFa Attribute rel on A elements
Any hyper-link can be given a “meaning”: This document is licensed under a Creative Commons License . Extracted triple: <> cc:license
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 18 / 29 RDFa Attribute rel on A elements
Any hyper-link can be given a “meaning”: This document is licensed under a Creative Commons License . Extracted triple: <> cc:license
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 18 / 29 Extracted triples: <> dc:title "Kransen" ; dc:created "1920" . Can also use content attribute together with property: September 16th at 4pm
RDFa The property attribute
rel is for resource objects, property for literal objects:
...Kransen
Written in 1920INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 19 / 29 Can also use content attribute together with property: September 16th at 4pm
RDFa The property attribute
rel is for resource objects, property for literal objects:
...Kransen
Written in 1920 Extracted triples: <> dc:title "Kransen" ; dc:created "1920" .INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 19 / 29 RDFa The property attribute
rel is for resource objects, property for literal objects:
...Kransen
Written in 1920 Extracted triples: <> dc:title "Kransen" ; dc:created "1920" . Can also use content attribute together with property: September 16th at 4pm INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 19 / 29 Extracted triples:RDFa Changing the Subject
about changes subject of contained rel and property annotations:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 20 / 29 RDFa Changing the Subject
about changes subject of contained rel and property annotations:
Extracted triples:INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 20 / 29 Missing URIs can lead to blank nodes:
Martin Giese
Email: [email protected]
RDFa Types and Blank Nodes
typeof adds an rdf:type triple
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 21 / 29 Extracted triples: [] a foaf:Person ; foaf:name "Martin Giese" ; foaf:mbox
RDFa Types and Blank Nodes
typeof adds an rdf:type triple Missing URIs can lead to blank nodes:
Martin Giese
Email: [email protected]
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 21 / 29 RDFa Types and Blank Nodes
typeof adds an rdf:type triple Missing URIs can lead to blank nodes:
Martin Giese
Email: [email protected]
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 21 / 29 RDFa Know Your Friends
Missing objects collected from contained elements (chaining):
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 22 / 29 RDFa Triples From Chaining Example
http:/...kjernsmo.net/
foaf:homepage foaf:name Kjetil rdf:type
foaf:knows
foaf.rdf#me foaf:Person foaf:knows
rdf:type
foaf:name foaf:homepage Leif Harald
http:/.../leifhka/
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 23 / 29 Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/
XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details!
Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/
RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details!
Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/
Treat links and text as subjects/objects and literals Many, many more details!
Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/
Many, many more details!
Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/ Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details!
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 See spec. at http://www.w3.org/TR/rdfa-syntax/ Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details! Specification hardly less complicated than RDF/XML
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details! Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details! Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/ Nothing you couldn’t do with a LINK and an RDF file
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details! Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/ Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details! Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/ Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 RDFa RDFa Summary
Allows to “hide” an RDF graph in an XHTML document XHTML processor can ignore RDFa RDFa processor can extract RDF graph Treat links and text as subjects/objects and literals Many, many more details! Specification hardly less complicated than RDF/XML See spec. at http://www.w3.org/TR/rdfa-syntax/ Nothing you couldn’t do with a LINK and an RDF file Can be convenient to have information in one place Used by Google as one data format for “Rich Snippets” https://developers.google.com/structured-data/ NOTE: this lecture was about RDFa 1.0. Search the web for RDFa 1.1!
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 24 / 29 Conclusion Outline
1 Reminder
2 Linking RDF to HTML
3 RDFa
4 Conclusion
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 25 / 29 The Jena API for RDF The SPARQL Query Language Basics of the RDFS and OWL ontology languages Basics of model semantics and reasoning Linked Open Data, RDFa Publishing Databases as RDF
Conclusion Topics Covered
RDF, principles, Turtle syntax
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 26 / 29 The SPARQL Query Language Basics of the RDFS and OWL ontology languages Basics of model semantics and reasoning Linked Open Data, RDFa Publishing Databases as RDF
Conclusion Topics Covered
RDF, principles, Turtle syntax The Jena API for RDF
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 26 / 29 Basics of the RDFS and OWL ontology languages Basics of model semantics and reasoning Linked Open Data, RDFa Publishing Databases as RDF
Conclusion Topics Covered
RDF, principles, Turtle syntax The Jena API for RDF The SPARQL Query Language
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 26 / 29 Basics of model semantics and reasoning Linked Open Data, RDFa Publishing Databases as RDF
Conclusion Topics Covered
RDF, principles, Turtle syntax The Jena API for RDF The SPARQL Query Language Basics of the RDFS and OWL ontology languages
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 26 / 29 Linked Open Data, RDFa Publishing Databases as RDF
Conclusion Topics Covered
RDF, principles, Turtle syntax The Jena API for RDF The SPARQL Query Language Basics of the RDFS and OWL ontology languages Basics of model semantics and reasoning
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 26 / 29 Publishing Databases as RDF
Conclusion Topics Covered
RDF, principles, Turtle syntax The Jena API for RDF The SPARQL Query Language Basics of the RDFS and OWL ontology languages Basics of model semantics and reasoning Linked Open Data, RDFa
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 26 / 29 Conclusion Topics Covered
RDF, principles, Turtle syntax The Jena API for RDF The SPARQL Query Language Basics of the RDFS and OWL ontology languages Basics of model semantics and reasoning Linked Open Data, RDFa Publishing Databases as RDF
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 26 / 29 (You ain’t seen nothing yet :-)
SW application structures Semantic Web Services Details of RDF/RDFS model semantics Some details of OWL Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . .
And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.)
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 (You ain’t seen nothing yet :-)
Semantic Web Services Details of RDF/RDFS model semantics Some details of OWL Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . .
And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 (You ain’t seen nothing yet :-)
Details of RDF/RDFS model semantics Some details of OWL Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . .
And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures Semantic Web Services
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 (You ain’t seen nothing yet :-)
Some details of OWL Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . .
And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures Semantic Web Services Details of RDF/RDFS model semantics
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 (You ain’t seen nothing yet :-)
Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . .
And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures Semantic Web Services Details of RDF/RDFS model semantics Some details of OWL
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 (You ain’t seen nothing yet :-)
Logical theory: Soundness, Completeness,. . .
And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures Semantic Web Services Details of RDF/RDFS model semantics Some details of OWL Details of OWL 2 profiles
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 (You ain’t seen nothing yet :-) And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures Semantic Web Services Details of RDF/RDFS model semantics Some details of OWL Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . .
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 And many more!
Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures Semantic Web Services Details of RDF/RDFS model semantics Some details of OWL Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . . (You ain’t seen nothing yet :-)
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 Conclusion Topics Not Covered
Rule Languages (SWRL, RIF, Jena rules, etc.) SW application structures Semantic Web Services Details of RDF/RDFS model semantics Some details of OWL Details of OWL 2 profiles Logical theory: Soundness, Completeness,. . . (You ain’t seen nothing yet :-) And many more!
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 27 / 29 Book on Semantic Web Programming Standards texts on W3C Web pages Google
Contact us for possible MSc topics!
Book on Foundations of SW Technologies Take a course in logic or automated reasoning For more information on practical questions:
Still not enough?
Conclusion Help! I Can’t Get Enough!
For more information on theory:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Book on Semantic Web Programming Standards texts on W3C Web pages Google
Contact us for possible MSc topics!
Take a course in logic or automated reasoning For more information on practical questions:
Still not enough?
Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Book on Semantic Web Programming Standards texts on W3C Web pages Google
Contact us for possible MSc topics!
For more information on practical questions:
Still not enough?
Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies Take a course in logic or automated reasoning
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Contact us for possible MSc topics!
Book on Semantic Web Programming Standards texts on W3C Web pages Google Still not enough?
Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies Take a course in logic or automated reasoning For more information on practical questions:
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Contact us for possible MSc topics!
Standards texts on W3C Web pages Google Still not enough?
Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies Take a course in logic or automated reasoning For more information on practical questions: Book on Semantic Web Programming
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Contact us for possible MSc topics!
Google Still not enough?
Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies Take a course in logic or automated reasoning For more information on practical questions: Book on Semantic Web Programming Standards texts on W3C Web pages
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Contact us for possible MSc topics!
Still not enough?
Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies Take a course in logic or automated reasoning For more information on practical questions: Book on Semantic Web Programming Standards texts on W3C Web pages Google
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Contact us for possible MSc topics!
Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies Take a course in logic or automated reasoning For more information on practical questions: Book on Semantic Web Programming Standards texts on W3C Web pages Google Still not enough?
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29 Conclusion Help! I Can’t Get Enough!
For more information on theory: Book on Foundations of SW Technologies Take a course in logic or automated reasoning For more information on practical questions: Book on Semantic Web Programming Standards texts on W3C Web pages Google Still not enough? Contact us for possible MSc topics!
INF3580/4580 :: Spring 2016 Lecture 15 :: 30th May 28 / 29