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RDF

Jun 09, 2022, 2 min read

RDF is a standard model for data interchange on the Web

RDF can be understood as a linking structure which forms a directed, labeled graph, where the edges represent the named link between two resources, represented by the graph nodes.

See also: LDP

RDF Triple

RDF extends the linking structure of the Web to use URIs to name the relationship between things as well as the two ends of the link (this is usually referred to as a “triple”). Much like a relational database, information in a triplestore is stored and retrieved via a query language.

A store of RDF Triples is called a triplestore.

From Intertwingle

Following a link only gives you one dimension of mobility. A search can be seen as following multiple links, and finding the intersection (or union) of the results of those links.

Any link-relationship should be searchable. For example:

  • All messages from person between date and date that have pattern in the body.
  • All messages from person which contain a message from person.
  • All messages to mailing-list which refer to URL.
  • All messages containing text in the main body, but not in an attachment.
  • All messages with an attachment whose file name contains string.

Turtle

Source: W3

A textual syntax for RDF called Turtle that allows an RDF graph to be completely written in a compact and natural text form, with shorthands for common usage patterns and datatypes

@base <http://example.org/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix rel: <http://www.perceive.net/schemas/relationship/> .
 
<#green-goblin>
    rel:enemyOf <#spiderman> ;
    a foaf:Person ;    # in the context of the Marvel universe
    foaf:name "Green Goblin" .
 
<#spiderman>
    rel:enemyOf <#green-goblin> ;
    a foaf:Person ;
    foaf:name "Spiderman", "Человек-паук"@ru .

JSON-LD

A JSON-LD document is both an RDF document and a JSON document and correspondingly represents an instance of an RDF data model

{
  "@context": "[https://json-ld.org/contexts/person.jsonld](https://json-ld.org/contexts/person.jsonld)",
  "@id": "[http://dbpedia.org/resource/John_Lennon](http://dbpedia.org/resource/John_Lennon)",
  "name": "John Lennon",
  "born": "1940-10-09",
  "spouse": "[http://dbpedia.org/resource/Cynthia_Lennon](http://dbpedia.org/resource/Cynthia_Lennon)"
}

Graph View

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