Embed Size (px)
Citation preview
OPEN GRAPH PROTOCOL
CLASS NOTES DECEMBER 1ST 2015
REVIEW
• Question: “Why is the web a giant book?”
• Text documents
• Basic unit is pages
• Question: “Why is the semantic web a giant database?
IF THE WORLD WIDE WEB IS A GIANT BOOK, THE SEMANTIC WEB
IS A GIANT DATABASE.-Sir Tim Berners-Lee
WHY DOES HE SAY THE WEB IS A GIANT BOOK?
IT’S BUILT OUT OF TEXT DOCUMENTS
THE BASIC UNIT IS A PAGE
WHY DOES HE SAY THE SEMANTIC WEB IS A GIANT DATABASE?
METADATA RECORDS
ITEMS SMALLER THAN THE PAGE LEVEL.
Think about <div itemscope>
NEXT EXAMPLE: FACEBOOK’S OPEN GRAPH PROTOCOL
BUT FIRST: SOME TECHNICAL TERMS
RDF TRIPLE
SUBJECT PREDICATE
OBJECT
IT’S A KIND OF GRAMMAR. IT EXPRESSES A
RELATIONSHIP.
NICHOLAS IS THE INSTRUCTOR FOR
DTC356
<SUBJECT>NICHOLAS <PREDICATE> INSTRUCTOR
<OBJECT> DTC356
OPEN GRAPH PROTOCOL
• Metadata refers to the entire page, not elements on the page
• markup goes in meta property tags in the page’s <head> element
• Unlike schema.org, OGP elements are invisible
• Unlike schema.org, you are describing the page, not a single element
• OGP markup makes your page exist on Facebook’s social graph
