JSON-LD reader/writer

JSON-LD reader/writer for RDF.rb and fully conforming JSON-LD processor.

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 = {
  "@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 = [{
    "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"]
}]

context = {
  "@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"
  }
}

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

Frame a Document

input = {
  "@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 = {
  "@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.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 = {
  "@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" ] }
}

JSON::LD::API.toRDF(input) =>
@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

input =
@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 =
{
  "@context": {
    "":       "http://manu.sporny.org/",
    "foaf":   "http://xmlns.com/foaf/0.1/"
  }
}

JSON::LD::API::fromRDF(input, context) =>
{
  "@context": {
    "":       "http://manu.sporny.org/",
    "foaf":   "http://xmlns.com/foaf/0.1/"
  },
  "@id":       ":#me",
  "@type":          "foaf:Person",
  "foaf:name":      "Manu Sporny",
  "foaf:knows": {
    "@type":          "foaf:Person",
    "foaf:name":      "Gregg Kellogg"
  }
}

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)

Documentation

Full documentation available on RubyDoc

Differences from JSON-LD API

The specified JSON-LD API is based on a WebIDL definition intended for use within the browser. This version implements a more Ruby-like variation of this API without the use of futures and callback arguments, preferring Ruby blocks. All API methods execute synchronously, so that the return from a method can 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.

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

  • Do your best to adhere to the existing coding conventions and idioms.
  • Don't use hard tabs, and don't leave trailing whitespace on any line.
  • Do document every method you add using YARD annotations. Read the tutorial or just look at the existing code for examples.
  • Don't touch the .gemspec, VERSION or AUTHORS files. If you need to change them, do so on your private branch only.
  • Do feel free to add yourself to the CREDITS file and the corresponding list in the the README. Alphabetical order applies.
  • Do note that in order for us to merge any non-trivial changes (as a rule of thumb, additions larger than about 15 lines of code), we need an explicit public domain dedication on record from you.

License

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