JSON-LD: JSON for Linked Data

JSON-LD is a set of W3C standards track specifications for representing Linked Data in JSON. It is fully compatible with the RDF data model, but allows developers to work with data entirely within JSON.

More information on JSON-LD can be found at http://json-ld.org/

1. JSON-LD
JSON for Linked Data
Gregg Kellogg
[email protected]
@gkellogg

2. JSON-LD
JSON for Linked Data
Gregg Kellogg
[email protected]
@gkellogg
Linking

3. JSON
JSON has taken over service APIs

4. Tower of Babel

5. Tower of Babel
{
"type": "User",
"followers": 35,
"html_url": "https://github.com/gkellogg",
"hireable": true,
"created_at": "2009-01-13T16:58:46Z",
"public_repos": 44,
"blog": "http://greggkellogg.net",
"bio": "Gregg is a Standards Architect ...",
"gravatar_id":
"42f948ad!3afaa52249d963117af7c8",
"following": 35,
"company": "Self",
"public_gists": 4,
"location": "San Rafael, CA",
"name": "Gregg Kellogg",
"email": "[email protected]",
"url": "https://api.github.com/users/gkellogg",
"avatar_url": "...",
"id": 46296,
"login": "gkellogg"
GitHub

6. Tower of Babel
{
"type": "User",
"followers": 35,
"html_url": "https://github.com/gkellogg",
"hireable": true,
"created_at": "2009-01-13T16:58:46Z",
"public_repos": 44,
"blog": "http://greggkellogg.net",
"bio": "Gregg is a Standards Architect ...",
"gravatar_id":
"42f948ad!3afaa52249d963117af7c8",
"following": 35,
"company": "Self",
"public_gists": 4,
"location": "San Rafael, CA",
"name": "Gregg Kellogg",
"email": "[email protected]",
"url": "https://api.github.com/users/gkellogg",
"avatar_url": "...",
"id": 46296,
"login": "gkellogg"
GitHub
{
"max_id": 195520745634406400,
"page": 1,
"query": "%40gkellogg",
"results": [{
"created_at": "Thu, 26 Apr 2012 14:32:33
+0000",
"from_user": "kendall",
"from_user_name": "Kendall Clark",
"id": 195520745634406400,
"in_reply_to_status_id":
195518881811529729,
"iso_language_code": "en",
"metadata": {"result_type": "recent"},
"text": "@Gkellogg Multiple resources in a
single JSON-LD struct/doc/message.",
"to_user": "Gkellogg",
"to_user_id": 6125262,
"to_user_name": "Gregg Kellogg"
}],
"results_per_page": 1,
"since_id": 0,
"since_id_str": "0"
}
Twitter

7. Tower of Babel
{
"type": "User",
"followers": 35,
"html_url": "https://github.com/gkellogg",
"hireable": true,
"created_at": "2009-01-13T16:58:46Z",
"public_repos": 44,
"blog": "http://greggkellogg.net",
"bio": "Gregg is a Standards Architect ...",
"gravatar_id":
"42f948ad!3afaa52249d963117af7c8",
"following": 35,
"company": "Self",
"public_gists": 4,
"location": "San Rafael, CA",
"name": "Gregg Kellogg",
"email": "[email protected]",
"url": "https://api.github.com/users/gkellogg",
"avatar_url": "...",
"id": 46296,
"login": "gkellogg"
GitHub
{
"max_id": 195520745634406400,
"page": 1,
"query": "%40gkellogg",
"results": [{
"created_at": "Thu, 26 Apr 2012 14:32:33
+0000",
"from_user": "kendall",
"from_user_name": "Kendall Clark",
"id": 195520745634406400,
"in_reply_to_status_id":
195518881811529729,
"iso_language_code": "en",
"metadata": {"result_type": "recent"},
"text": "@Gkellogg Multiple resources in a
single JSON-LD struct/doc/message.",
"to_user": "Gkellogg",
"to_user_id": 6125262,
"to_user_name": "Gregg Kellogg"
}],
"results_per_page": 1,
"since_id": 0,
"since_id_str": "0"
}
Twitter
{
"id": "1236600216",
"name": "Gregg Kellogg",
"first_name": "Gregg",
"last_name": "Kellogg",
"link": "https://www.facebook.com/
gkellogg",
"username": "gkellogg",
"gender": "male",
"locale": "en_US"
}
Facebook

8. Introducing JSON-LD
JSON-based syntax to express linked data
@context
@id
@type
@value
@language
@graph
@list
@set

9. Self-describing Messages
•
Give objects types
(@type)
{
"@context": {
"schema": "http://schema.org/",
"Person": "schema:Person",
"colleagues": {"@id": "schema:colleagues", "@type": "@id"},
"name": "schema:name",
"image": {"@id": "schema:image", "@type": "@id"},
"url": {"@id": "schema:url", "@type": "@id"}
}
}
{
"@context": "http://example.com/context.jsonld",
"@type": "Person",
"image": "http://localhost:9393/examples/schema.org/janedoe.jpg",
"colleagues": [
"http://www.xyz.edu/students/alicejones.html",
"http://www.xyz.edu/students/bobsmith.html"
],
"name": "Jane Doe",
"url": "http://www.janedoe.com"
}

10. Self-describing Messages
•
Give objects types
(@type)
•
Associate properties
with IRIs
{
"@context": {
"schema": "http://schema.org/",
"Person": "schema:Person",
"colleagues": {"@id": "schema:colleagues", "@type": "@id"},
"name": "schema:name",
"image": {"@id": "schema:image", "@type": "@id"},
"url": {"@id": "schema:url", "@type": "@id"}
}
}
{
"@context": "http://example.com/context.jsonld",
"@type": "Person",
"image": "http://localhost:9393/examples/schema.org/janedoe.jpg",
"colleagues": [
"http://www.xyz.edu/students/alicejones.html",
"http://www.xyz.edu/students/bobsmith.html"
],
"name": "Jane Doe",
"url": "http://www.janedoe.com"
}

11. Self-describing Messages
•
Give objects types
(@type)
•
Associate properties
with IRIs
•
Use terms defined in a
referenced context
{
"@context": {
"schema": "http://schema.org/",
"Person": "schema:Person",
"colleagues": {"@id": "schema:colleagues", "@type": "@id"},
"name": "schema:name",
"image": {"@id": "schema:image", "@type": "@id"},
"url": {"@id": "schema:url", "@type": "@id"}
}
}
{
"@context": "http://example.com/context.jsonld",
"@type": "Person",
"image": "http://localhost:9393/examples/schema.org/janedoe.jpg",
"colleagues": [
"http://www.xyz.edu/students/alicejones.html",
"http://www.xyz.edu/students/bobsmith.html"
],
"name": "Jane Doe",
"url": "http://www.janedoe.com"
}

12. Self-describing Messages
•
Give objects types
(@type)
•
Associate properties
with IRIs
•
Use terms defined in a
referenced context
•
Specify property types
in context
{
"@context": {
"schema": "http://schema.org/",
"Person": "schema:Person",
"colleagues": {"@id": "schema:colleagues", "@type": "@id"},
"name": "schema:name",
"image": {"@id": "schema:image", "@type": "@id"},
"url": {"@id": "schema:url", "@type": "@id"}
}
}
{
"@context": "http://example.com/context.jsonld",
"@type": "Person",
"image": "http://localhost:9393/examples/schema.org/janedoe.jpg",
"knows": [
"http://www.xyz.edu/students/alicejones.html",
"http://www.xyz.edu/students/bobsmith.html"
],
"name": "Jane Doe",
"url": "http://www.janedoe.com"
}

13. Language Principles

14. {
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": "http://www.markus-lanthaler.com/"
}
•
Make full use of JSON syntactic
representations
•
Object defines a subject
definition

15. {
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": "http://www.markus-lanthaler.com/"
}
•
Make full use of JSON syntactic
representations
•
Object defines a subject
definition
{ "@id": "http://greggkellogg.net/foaf#me" }
•
Also used for subject
reference and value
representations

16. {
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": "http://www.markus-lanthaler.com/"
}
•
Make full use of JSON syntactic
representations
•
Object defines a subject
definition
{ "@id": "http://greggkellogg.net/foaf#me" }
•
Also used for subject
reference and value
representations
•
Arrays describe sets of unordered
values
•
Single values can skip array
{
"@type": "Recipe",
"name": "Mom's World Famous Banana Bread",
"ingredients": [
"3 or 4 ripe bananas, smashed",
"1 egg",
"3/4 cup of sugar"
],
"nutrition": [{
"@type": ["NutritionInformation"],
"calories": ["240 calories"],
"fatContent": ["9 grams fat"]
}]
}

17. {
"@id": "http://greggkellogg.net/foaf#me",
"@type": "http://schema.org/Person",
"http://schema.org/name": "Gregg Kellogg",
"http://schema.org/knows": {
"@id": "http://www.markus-lanthaler.com/"
}
}
•
Define terms to use short
property names
•
Convenient for JavaScript “.”
notation
{
"@context": {
"Person": "http://schema.org/Person",
"name": "http://schema.org/name",
"knows”: "http://schema.org/knows"
},
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": {"@id": "http://www.markus-lanthaler.com/"}
}

18. •
Define terms to use short
property names
•
Convenient for JavaScript “.”
notation
•
Add @type coercions to
use simple string value.
{
"@id": "http://greggkellogg.net/foaf#me",
"@type": "http://schema.org/Person",
"http://schema.org/name": "Gregg Kellogg",
"http://schema.org/knows": {
"@id": "http://www.markus-lanthaler.com/"
}
}
{
"@context": {
"schema": "http://schema.org/",
"Person": "schema:Person",
"name": "schema:name",
"knows”: {
"@id": "schema:knows",
"@type": "@id"
},
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": "http://www.markus-lanthaler.com/"
}

19. •
Define terms to use short
property names
•
Convenient for JavaScript “.”
notation
•
Add @type coercions to
use simple string value.
{
"@id": "http://greggkellogg.net/foaf#me",
"@type": "http://schema.org/Person",
"http://schema.org/name": "Gregg Kellogg",
"http://schema.org/knows": {
"@id": "http://www.markus-lanthaler.com/"
}
}
{
"@context": {
"schema": "http://schema.org/",
"Person": "schema:Person",
"name": "schema:name",
"knows”: {
"@id": "schema:knows",
"@type": "@id"
}
}
•
Use external @context.
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": "http://www.markus-lanthaler.com/"
}

20. •
Define referenced subject
definition with chaining
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": {
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
}

21. •
Define referenced subject
definition with chaining
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": {
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
}
•
Add @language to values.{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"honorificSuffix": {"@value": "M.S.", "@language": "en"},
"knows": {
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"honorificSuffix": {"@value": "Dipl.Ing.", "@language": "de"},
"knows" "http://greggkellogg.net/foaf#me"
}
}

22. •
Add @type to values.
•
Link to externally defined
resources.
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"birthDate": {"@value": "1957-02-27", "@type": "xsd:date"},
"honorificSuffix": {"@value": "M.S.", "@language": "en"},
"knows": "http://www.markus-lanthaler.com/"
}

23. •
Add property @type and
@language definitions to
context
{
"@context": {
"schema": "http://schema.org/",
"Person": "schema:Person",
"name": "schema:name",
"birthDate”: {
"@id": "schema: birthDate","@type": "xsd:date"
},
"honorificSuffix”: {
"@id": "schema:honorificSuffix","@language": "en"
},
"knows”: {"@id": "schema:knows","@type": "@id"}
},
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"birthDate": "1957-02-27",
"honorificSuffix": "M.S.",
"knows": "http://www.markus-lanthaler.com/"
}

24. •More features defined in the syntax
specification*:
•@set, @list, Compact IRIs, Unlabeled
Nodes
•Embedded @context definitions
•Named Graphs
* http://json-ld.org/spec/latest/json-ld-syntax

25. Examples “In the Wild”

26. DBpedia
{
"@graph": [
{
"@id": "http://dbpedia.org/resource/DBpedia",
"http://dbpedia.org/property/genre" : [ "http://dbpedia.org/resource/Linked_Data" ]
} ,
{
"@id": "http://dbpedia.org/resource/Linked_Data",
"@type" : [ "http://dbpedia.org/class/yago/Buzzwords" ] ,
"http://www.w3.org/2002/07/owl#sameAs" : ["http://rdf.freebase.com/ns/m/02r2kb1"] ,
"http://www.w3.org/2000/01/rdf-schema#comment": [
{ "@value" : "Linked Open Data (LOD) bezeichnet ..." , "@language" : "de" } ,
{ "@value" : "In computing, linked Data describes ..." , "@language" : "en" } ],
"http://purl.org/dc/terms/subject" : [
"http://dbpedia.org/resource/Category:World_Wide_Web" ,
"http://dbpedia.org/resource/Category:Buzzwords" ,
"http://dbpedia.org/resource/Category:Semantic_Web"
] ,
...
}]
}
http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=DESCRIBE+<http://dbpedia.org/resource/
Linked_Data>&output=application%2Fld%2Bjson

27. Schema.org
http://linter.structured-data.org/examples/
schema.org/sdo_eg_rdfa_12.html
Using RDFa to JSON-LD bookmarklet*
* bookmarklet courtesy of Niklas Lindström

28. Schema.org
http://linter.structured-data.org/examples/
schema.org/sdo_eg_rdfa_12.html
{
"@context": {...},
"@graph": [{
"@id": "http://linter.structured-data.org/examples/schema.org/Recipe.rdfa",
"rdfa:usesVocabulary": "http://schema.org/"
}, {
"@type": ["Recipe"],
"name": ["Mom's World Famous Banana Bread"],
"author": ["John Smith"],
"publishDate": ["2009-05-08"],
"image": [{"@id": ".../bananabread.jpg"}],
"description": ["This classic banana bread recipe ..."],
"prepTime": ["PT15M"],
"cookTime": ["PT1H"],
"recipeYield": ["1 loaf"],
"nutrition": [{
"@type": ["NutritionInformation"],
"calories": ["240 calories"],
"fatContent": ["9 grams fat"]
}],
"ingredients": [
"3 or 4 ripe bananas, smashed",
"1 egg",
"3/4 cup of sugar"
],
"recipeInstructions": ["Preheat the oven to 350 degrees..."],
"interactionCount": ["UserComments:140"]
}]
}
Using RDFa to JSON-LD bookmarklet*
* bookmarklet courtesy of Niklas Lindström

29. Drupal

30. Drupal
{
"@context": "http://drupal.example.org/context.jsonld",
"@id": "http://dev.fga-directory.gotpantheon.com/
occupation/al/kosovo/occupy-prishtina",
"@type": ["ows:Occupation", "schema:Organization"],
"foaf:name": "Occupy Prishtina",
"schema:name": "Occupy Prishtina",
"dc:date": "2012-02-12T21:18:08-05:00",
"dc:created": "2012-02-12T21:18:08-05:00",
"dc:modified": "2012-02-12T21:57:52-05:00",
"sioc:num_replies": 0,
"schema:foundingDate": "2011-10-15T00:00:00-04:00",
"ows:twitter_account": "@OccupyPrishtina",
"foaf:mbox": "",
"schema:telephone": "",
"foaf:phone": ""
}
http://dev.fga-directory.gotpantheon.com/node/20080.jsonld

31. PaySwarm
{
"@context": "http://purl.org/payswarm/v1",
"@graph": {
"@type": "Transaction",
"transfer": {
"@type": "Transfer",
"amount": "7.50",
"currency": "USD",
"source": "https://bluebank.com/people/manu/accounts/food",
"destination": "https://redbank.com/people/gregg/accounts/hosting",
"comment": "Chipping in for the Pizza Party tomorrow."
},
},
"signature": {
"@type": "JsonLdSignature",
"created": "2011-09-23T20:21:34Z",
"signer": "http://bluebank.com/people/manu/keys/5",
"signatureValue": "ExMgoDIyOGQzNGVkM...mOWM32Nj4NTIyZTkZDYMI="
}
}Named
Graph Signature of
Named
Graph

32. Working with data
{
"@context": "http://drupal.example.org/context.jsonld",
"@id": "http://dev.fga-directory.gotpantheon.com/
occupation/al/kosovo/occupy-prishtina",
"@type": ["ows:Occupation", "schema:Organization"],
"foaf:name": "Occupy Prishtina",
"schema:name": "Occupy Prishtina",
"dc:date": "2012-02-12T21:18:08-05:00",
"dc:created": "2012-02-12T21:18:08-05:00",
"dc:modified": "2012-02-12T21:57:52-05:00",
"sioc:num_replies": 0,
"schema:foundingDate": "2011-10-15T00:00:00-04:00",
"ows:twitter_account": "@OccupyPrishtina",
"foaf:mbox": "",
"schema:telephone": "",
"foaf:phone": ""
}
•
Expand documents to remove effect of @context.

33. Working with data
{
"@context": "http://drupal.example.org/context.jsonld",
"@id": "http://dev.fga-directory.gotpantheon.com/
occupation/al/kosovo/occupy-prishtina",
"@type": ["ows:Occupation", "schema:Organization"],
"foaf:name": "Occupy Prishtina",
"schema:name": "Occupy Prishtina",
"dc:date": "2012-02-12T21:18:08-05:00",
"dc:created": "2012-02-12T21:18:08-05:00",
"dc:modified": "2012-02-12T21:57:52-05:00",
"sioc:num_replies": 0,
"schema:foundingDate": "2011-10-15T00:00:00-04:00",
"ows:twitter_account": "@OccupyPrishtina",
"foaf:mbox": "",
"schema:telephone": "",
"foaf:phone": ""
}
•
Expand documents to remove effect of @context.
[{
"@id": "http://dev.fga-directory.gotpantheon.com/occupation/al/kosovo/occupy-prishtina",
"@type": ["http://vocab.occupy.net/ows#Occupation", "http://schema.org/Organization"],
"http://purl.org/dc/terms/created": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:18:08-05:00"
}],
"http://purl.org/dc/terms/date": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:18:08-05:00"
}],
"http://purl.org/dc/terms/modified": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:57:52-05:00"
}],
"http://rdfs.org/sioc/ns#num_replies": [{
"@type": "http://www.w3.org/2001/XMLSchema#integer",
"@value": "0"
}],
"http://schema.org/foundingDate": [{
"@type": "http://www.w3.org/2001/XMLSchema#date",
"@value": "2011-10-15T00:00:00-04:00"
}],
"http://schema.org/name": ["Occupy Prishtina"],
"http://schema.org/telephone": [""],
"http://vocab.occupy.net/ows#twitter_account": ["@OccupyPrishtina"],
"http://xmlns.com/foaf/0.1/mbox": [""],
"http://xmlns.com/foaf/0.1/name": ["Occupy Prishtina"],
"http://xmlns.com/foaf/0.1/phone": [""]
}]

34. [{
"@id": "http://dev.fga-directory.gotpantheon.com/occupation/al/kosovo/occupy-prishtina",
"@type": ["http://vocab.occupy.net/ows#Occupation", "http://schema.org/Organization"],
"http://purl.org/dc/terms/created": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:18:08-05:00"
}],
"http://purl.org/dc/terms/date": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:18:08-05:00"
}],
"http://purl.org/dc/terms/modified": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:57:52-05:00"
}],
"http://rdfs.org/sioc/ns#num_replies": [{
"@type": "http://www.w3.org/2001/XMLSchema#integer",
"@value": "0"
}],
"http://schema.org/foundingDate": [{
"@type": "http://www.w3.org/2001/XMLSchema#date",
"@value": "2011-10-15T00:00:00-04:00"
}],
"http://schema.org/name": ["Occupy Prishtina"],
"http://schema.org/telephone": [""],
"http://vocab.occupy.net/ows#twitter_account": ["@OccupyPrishtina"],
"http://xmlns.com/foaf/0.1/mbox": [""],
"http://xmlns.com/foaf/0.1/name": ["Occupy Prishtina"],
"http://xmlns.com/foaf/0.1/phone": [""]
}]
Working with data
•
Compact documents to apply a @context.

35. [{
"@id": "http://dev.fga-directory.gotpantheon.com/occupation/al/kosovo/occupy-prishtina",
"@type": ["http://vocab.occupy.net/ows#Occupation", "http://schema.org/Organization"],
"http://purl.org/dc/terms/created": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:18:08-05:00"
}],
"http://purl.org/dc/terms/date": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:18:08-05:00"
}],
"http://purl.org/dc/terms/modified": [{
"@type": "http://www.w3.org/2001/XMLSchema#dateTime",
"@value": "2012-02-12T21:57:52-05:00"
}],
"http://rdfs.org/sioc/ns#num_replies": [{
"@type": "http://www.w3.org/2001/XMLSchema#integer",
"@value": "0"
}],
"http://schema.org/foundingDate": [{
"@type": "http://www.w3.org/2001/XMLSchema#date",
"@value": "2011-10-15T00:00:00-04:00"
}],
"http://schema.org/name": ["Occupy Prishtina"],
"http://schema.org/telephone": [""],
"http://vocab.occupy.net/ows#twitter_account": ["@OccupyPrishtina"],
"http://xmlns.com/foaf/0.1/mbox": [""],
"http://xmlns.com/foaf/0.1/name": ["Occupy Prishtina"],
"http://xmlns.com/foaf/0.1/phone": [""]
}]
Working with data
•
Compact documents to apply a @context.
{
"@context": "http://drupal.example.org/context.jsonld",
"@id": "http://dev.fga-directory.gotpantheon.com/
occupation/al/kosovo/occupy-prishtina",
"@type": ["ows:Occupation", "schema:Organization"],
"foaf:name": "Occupy Prishtina",
"schema:name": "Occupy Prishtina",
"dc:date": "2012-02-12T21:18:08-05:00",
"dc:created": "2012-02-12T21:18:08-05:00",
"dc:modified": "2012-02-12T21:57:52-05:00",
"sioc:num_replies": 0,
"schema:foundingDate": "2011-10-15T00:00:00-04:00",
"ows:twitter_account": "@OccupyPrishtina",
"foaf:mbox": "",
"schema:telephone": "",
"foaf:phone": ""
}

36. Working with data
{
"@context": {
"dc": "http://purl.org/dc/elements/1.1/",
"ex": "http://example.org/vocab#",
"contains": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org/test/#library",
"@type": "ex:Library",
"ex:contains": "http://example.org/test#book"
}, {
"@id": "http://example.org/test#book",
"@type": "ex:Book",
"dc:contributor": "Writer",
"dc:title": "My Book",
"ex:contains": "http://example.org/test#chapter"
}, {
"@id": "http://example.org/test#chapter",
"@type": "ex:Chapter",
"dc:description": "Fun",
"dc:title": "Chapter One"
}]
}
•
Frame documents to impose structure
input

37. Working with data
{
"@context": {
"dc": "http://purl.org/dc/elements/1.1/",
"ex": "http://example.org/vocab#",
"contains": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org/test/#library",
"@type": "ex:Library",
"ex:contains": "http://example.org/test#book"
}, {
"@id": "http://example.org/test#book",
"@type": "ex:Book",
"dc:contributor": "Writer",
"dc:title": "My Book",
"ex:contains": "http://example.org/test#chapter"
}, {
"@id": "http://example.org/test#chapter",
"@type": "ex:Chapter",
"dc:description": "Fun",
"dc:title": "Chapter One"
}]
}
•
Frame documents to impose structure
input
{
"@context": {
"dc": "http://purl.org/dc/elements/1.1/",
"ex": "http://example.org/vocab#",
"contains": {“@id”: “ex:contains”, "@type": "@id",
“title”: “dc:title”
},
"@type": "ex:Library",
"contains": {
"@type": "ex:Book",
"contains": {
"@type": "ex:Chapter"
}
}
}
+
frame

38. Working with data
{
"@context": {
"dc": "http://purl.org/dc/elements/1.1/",
"ex": "http://example.org/vocab#",
"contains": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org/test/#library",
"@type": "ex:Library",
"ex:contains": "http://example.org/test#book"
}, {
"@id": "http://example.org/test#book",
"@type": "ex:Book",
"dc:contributor": "Writer",
"dc:title": "My Book",
"ex:contains": "http://example.org/test#chapter"
}, {
"@id": "http://example.org/test#chapter",
"@type": "ex:Chapter",
"dc:description": "Fun",
"dc:title": "Chapter One"
}]
}
•
Frame documents to impose structure
input
{
"@context": {
"dc": "http://purl.org/dc/elements/1.1/",
"ex": "http://example.org/vocab#",
"contains": {“@id”: “ex:contains”, "@type": "@id",
“title”: “dc:title”
},
"@type": "ex:Library",
"contains": {
"@type": "ex:Book",
"contains": {
"@type": "ex:Chapter"
}
}
}
+
frame
{
"@context": {
"dc": "http://purl.org/dc/elements/1.1/",
"ex": "http://example.org/vocab#",,
"contains": {“@id”: “ex:contains”, "@type": "@id"
“title”: “dc:title”
},
"@graph": [{
"@id": "http://example.org/test/#library",
"@type": "ex:Library",
"contains": {
"@id": "http://example.org/test#book",
"@type": "ex:Book",
"dc:contributor": "Writer",
"title": "My Book",
"contains": {
"@id": "http://example.org/test#chapter",
"@type": "ex:Chapter",
"dc:description": "Fun",
"title": "Chapter One"
}
}
}]
}
output
JavaScript object path: data[‘@graph][0].contains.contains.title

39. Retrofit existing APIs
GET /foaf.json HTTP/1.1
Host: greggkellogg.net
Accept: application/json,*/*;q=0.1
====================================
HTTP/1.0 200 OK
...
Content-Type: application/json
Link: <http://json-ld.org/contexts/person>; rel="describedby"; type="application/ld+json"
{
"name": "Gregg Kellogg",
"homepage": "http://greggkellogg.net/",
"depiction": "http://twitter.com/account/profile_image/gkellogg"
}

40. Macros
•
Transform information
•
Add @id to data
•
Other programatic
transformations
{
"type": "User",
"followers": 35,
"name": "Gregg Kellogg",
"email": "[email protected]",
"url": "https://api.github.com/users/
gkellogg",
"avatar_url": "...",
"id": 46296,
"login": "gkellogg"
}
* json-ld-macros courtesy of Antonio Garrote

41. Macros
•
Transform information
•
Add @id to data
•
Other programatic
transformations
{
"type": "User",
"followers": 35,
"name": "Gregg Kellogg",
"email": "[email protected]",
"url": "https://api.github.com/users/
gkellogg",
"avatar_url": "...",
"id": 46296,
"login": "gkellogg"
}
* json-ld-macros courtesy of Antonio Garrote

42. Macros
•
Transform information
•
Add @id to data
•
Other programatic
transformations
{
"type": "User",
"followers": 35,
"name": "Gregg Kellogg",
"email": "[email protected]",
"url": "https://api.github.com/users/
gkellogg",
"avatar_url": "...",
"id": 46296,
"login": "gkellogg"
}
* json-ld-macros courtesy of Antonio Garrote
{
"https://api.github.com/users/*": {
"$": {
"@context": {
"foaf": "http://xmlns.com/foaf/0.1/",
"foaf:depiction": {"@type": "@id"},
"gh": "https://api.github.com/vocabulary#"
},
"@id": [{"f:valueof": "login"},
{"f:prefix": "http://github.com/"}],
"@ns": {
"ns:default": "gh",
"ns:replace": {"avatar_url": "foaf:depiction", "name":
"foaf:name"}
},
"@only": ["avatar_url", "name", "followers"],
"@type": ["gh:User", "foaf:Person"]
}
}
}
+

43. Macros
•
Transform information
•
Add @id to data
•
Other programatic
transformations
{
"type": "User",
"followers": 35,
"name": "Gregg Kellogg",
"email": "[email protected]",
"url": "https://api.github.com/users/
gkellogg",
"avatar_url": "...",
"id": 46296,
"login": "gkellogg"
}
* json-ld-macros courtesy of Antonio Garrote
{
"https://api.github.com/users/*": {
"$": {
"@context": {
"foaf": "http://xmlns.com/foaf/0.1/",
"foaf:depiction": {"@type": "@id"},
"gh": "https://api.github.com/vocabulary#"
},
"@id": [{"f:valueof": "login"},
{"f:prefix": "http://github.com/"}],
"@ns": {
"ns:default": "gh",
"ns:replace": {"avatar_url": "foaf:depiction", "name":
"foaf:name"}
},
"@only": ["avatar_url", "name", "followers"],
"@type": ["gh:User", "foaf:Person"]
}
}
}
+
{
"@context": {
"foaf": "http://xmlns.com/foaf/0.1/",
"foaf:depiction": {"@type": "@id"},
"gh": "https://api.github.com/
vocabulary#"
},
"@id": "https://api.github.com/users/
gkellogg",
"@type": ["gh:User", “foaf:Person”],
"foaf:name": "Gregg Kellogg",
"foaf:depiction": "http://...",
“gh:followers”: 35

44. The “LD” in JSON-LD
•
IRIs are first-class
citizens
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": "http://www.markus-lanthaler.com/"
}
http://greggkellogg.net/foaf
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
http://www.markus-lanthaler.com

45. The “LD” in JSON-LD
•
IRIs are first-class
citizens
•
Object definitions may
be referenced or
embedded
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": {
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
} {
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": "http://www.markus-lanthaler.com/"
}
http://greggkellogg.net/foaf
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
http://www.markus-lanthaler.com

46. RDF 
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": {
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
}

47. RDF 
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": {
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
}

48. RDF 
{
"@context": "http://json-ld.org/contexts/person",
"@id": "http://greggkellogg.net/foaf#me",
"@type": "Person",
"name": "Gregg Kellogg",
"knows": {
"@id": "http://www.markus-lanthaler.com/",
"@type": "Person",
"name": "Markus Lanthaler",
"knows" "http://greggkellogg.net/foaf#me"
}
}
@prefix: schema <http://schema.org/>
<http://greggkellogg.net/foaf#me> a schema:Person;
schema:name “Gregg Kellogg”;
shema:knows <http://www.markus-lanthaler.com/” .
<http://www.markus-lanthaler.com/> a schema:Person
schema:name “Markus Lanthaler”
schema:knows <http://greggkellogg.net/foaf#me> .

49. JSON-LD API
•compact – use minimal representation
using a supplied @context
•expand – expand to full form, removing
embedded @context definitions
•frame – query for JSON-LD
•fromRDF/toRDF

50. More Information
json-ld.org
w3c
JavaScript
Ruby
Python
Java
C++
PHP
Gregg Kellogg
@gkellogg
[email protected]
http://greggkellogg.net/