View on GitHub

Json-ld

Ruby JSON-LD reader/writer for RDF.rb

Download this project as a .zip file Download this project as a tar.gz file

JSON-LD reader/writer

JSON-LD reader/writer for RDF.rb and fully conforming JSON-LD API processor. Additionally this gem implements JSON-LD Framing.

Gem Version Build Status

Features

JSON::LD parses and serializes JSON-LD into RDF and implements expansion, compaction and framing API interfaces.

Install with gem install json-ld

Examples

require 'rubygems'
require 'json/ld'

Expand a Document

input = JSON.parse %({
  "@context": {
    "name": "http://xmlns.com/foaf/0.1/name",
    "homepage": "http://xmlns.com/foaf/0.1/homepage",
    "avatar": "http://xmlns.com/foaf/0.1/avatar"
  },
  "name": "Manu Sporny",
  "homepage": "http://manu.sporny.org/",
  "avatar": "http://twitter.com/account/profile_image/manusporny"
})
JSON::LD::API.expand(input) =>

[{
    "http://xmlns.com/foaf/0.1/name": ["Manu Sporny"],
    "http://xmlns.com/foaf/0.1/homepage": ["http://manu.sporny.org/"],
    "http://xmlns.com/foaf/0.1/avatar": ["http://twitter.com/account/profile_image/manusporny"]
}]

Compact a Document

input = JSON.parse %([{
    "http://xmlns.com/foaf/0.1/name": ["Manu Sporny"],
    "http://xmlns.com/foaf/0.1/homepage": [{"@id": "http://manu.sporny.org/"}],
    "http://xmlns.com/foaf/0.1/avatar": [{"@id": "http://twitter.com/account/profile_image/manusporny"}]
}])

context = JSON.parse(%({
  "@context": {
    "name": "http://xmlns.com/foaf/0.1/name",
    "homepage": {"@id": "http://xmlns.com/foaf/0.1/homepage", "@type": "@id"},
    "avatar": {"@id": "http://xmlns.com/foaf/0.1/avatar", "@type": "@id"}
  }
}))['@context']

JSON::LD::API.compact(input, context) =>
{
    "@context": {
      "name": "http://xmlns.com/foaf/0.1/name",
      "homepage": {"@id": "http://xmlns.com/foaf/0.1/homepage", "@type": "@id"},
      "avatar": {"@id": "http://xmlns.com/foaf/0.1/avatar", "@type": "@id"}
    },
    "avatar": "http://twitter.com/account/profile_image/manusporny",
    "homepage": "http://manu.sporny.org/",
    "name": "Manu Sporny"
}

Frame a Document

input = JSON.parse %({
  "@context": {
    "Book":         "http://example.org/vocab#Book",
    "Chapter":      "http://example.org/vocab#Chapter",
    "contains":     {"@id": "http://example.org/vocab#contains", "@type": "@id"},
    "creator":      "http://purl.org/dc/terms/creator",
    "description":  "http://purl.org/dc/terms/description",
    "Library":      "http://example.org/vocab#Library",
    "title":        "http://purl.org/dc/terms/title"
  },
  "@graph":
  [{
    "@id": "http://example.com/library",
    "@type": "Library",
    "contains": "http://example.org/library/the-republic"
  },
  {
    "@id": "http://example.org/library/the-republic",
    "@type": "Book",
    "creator": "Plato",
    "title": "The Republic",
    "contains": "http://example.org/library/the-republic#introduction"
  },
  {
    "@id": "http://example.org/library/the-republic#introduction",
    "@type": "Chapter",
    "description": "An introductory chapter on The Republic.",
    "title": "The Introduction"
  }]
})

frame = JSON.parse %({
  "@context": {
    "Book":         "http://example.org/vocab#Book",
    "Chapter":      "http://example.org/vocab#Chapter",
    "contains":     "http://example.org/vocab#contains",
    "creator":      "http://purl.org/dc/terms/creator",
    "description":  "http://purl.org/dc/terms/description",
    "Library":      "http://example.org/vocab#Library",
    "title":        "http://purl.org/dc/terms/title"
  },
  "@type": "Library",
  "contains": {
    "@type": "Book",
    "contains": {
      "@type": "Chapter"
    }
  }
})

JSON::LD::API.frame(input, frame) =>
{
  "@context": {
    "Book": "http://example.org/vocab#Book",
    "Chapter": "http://example.org/vocab#Chapter",
    "contains": "http://example.org/vocab#contains",
    "creator": "http://purl.org/dc/terms/creator",
    "description": "http://purl.org/dc/terms/description",
    "Library": "http://example.org/vocab#Library",
    "title": "http://purl.org/dc/terms/title"
  },
  "@graph": [
    {
      "@id": "http://example.com/library",
      "@type": "Library",
      "contains": {
        "@id": "http://example.org/library/the-republic",
        "@type": "Book",
        "contains": {
          "@id": "http://example.org/library/the-republic#introduction",
          "@type": "Chapter",
          "description": "An introductory chapter on The Republic.",
          "title": "The Introduction"
        },
        "creator": "Plato",
        "title": "The Republic"
      }
    }
  ]
}

Turn JSON-LD into RDF (Turtle)

input = JSON.parse %({
  "@context": {
    "":       "http://manu.sporny.org/",
    "foaf":   "http://xmlns.com/foaf/0.1/"
  },
  "@id":       "http://example.org/people#joebob",
  "@type":          "foaf:Person",
  "foaf:name":      "Joe Bob",
  "foaf:nick":      { "@list": [ "joe", "bob", "jaybe" ] }
})

graph = RDF::Graph.new << JSON::LD::API.toRdf(input)

require 'rdf/turtle'
graph.dump(:ttl, :prefixes => {:foaf => "http://xmlns.com/foaf/0.1/"})
@prefix foaf: <http://xmlns.com/foaf/0.1/> .

<http://example.org/people#joebob> a foaf:Person;
   foaf:name "Joe Bob";
   foaf:nick ("joe" "bob" "jaybe") .

Turn RDF into JSON-LD

require 'rdf/turtle'
input = RDF::Graph.new << RDF::Turtle::Reader.new(%(
  @prefix foaf: <http://xmlns.com/foaf/0.1/> .

  <http://manu.sporny.org/#me> a foaf:Person;
     foaf:knows [ a foaf:Person;
       foaf:name "Gregg Kellogg"];
     foaf:name "Manu Sporny" .
))

context = JSON.parse %({
  "@context": {
    "":       "http://manu.sporny.org/",
    "foaf":   "http://xmlns.com/foaf/0.1/"
  }
})

compacted = nil
JSON::LD::API::fromRdf(input) do |expanded|
  compacted = JSON::LD::API.compact(expanded, context['@context'])
end
compacted =>
  [
    {
      "@id": "_:g70265766605380",
      "@type": ["http://xmlns.com/foaf/0.1/Person"],
      "http://xmlns.com/foaf/0.1/name": [{"@value": "Gregg Kellogg"}]
    },
    {
      "@id": "http://manu.sporny.org/#me",
      "@type": ["http://xmlns.com/foaf/0.1/Person"],
      "http://xmlns.com/foaf/0.1/knows": [{"@id": "_:g70265766605380"}],
      "http://xmlns.com/foaf/0.1/name": [{"@value": "Manu Sporny"}]
    }
  ]

RDF Reader and Writer

{JSON::LD} also acts as a normal RDF reader and writer, using the standard RDF.rb reader/writer interfaces:

graph = RDF::Graph.load("etc/doap.jsonld", :format => :jsonld)
graph.dump(:jsonld, :standard_prefixes => true)

RDF::GRAPH#dump can also take a :context option to use a separately defined context

Documentation

Full documentation available on RubyDoc

Differences from JSON-LD API

The specified JSON-LD API is based on a WebIDL definition implementing Promises intended for use within a browser. This version implements a more Ruby-like variation of this API without the use of promises or callback arguments, preferring Ruby blocks. All API methods execute synchronously, so that the return from a method can typically be used as well as a block.

Note, the API method signatures differed in versions before 1.0, in that they also had a callback parameter. And 1.0.6 has some other minor method signature differences than previous versions. This should be the only exception to the use of semantic versioning.

Principal Classes

Dependencies

Installation

The recommended installation method is via RubyGems. To install the latest official release of the JSON-LD gem, do:

% [sudo] gem install json-ld

Download

To get a local working copy of the development repository, do:

% git clone git://github.com/ruby-rdf/json-ld.git

Mailing List

Author

Contributing

License

This is free and unencumbered public domain software. For more information, see http://unlicense.org/ or the accompanying {file:UNLICENSE} file.