json-gold

README

JSON-goLD

This library is an implementation of the JSON-LD 1.1 specification in Go. It supports both URDNA2015 and URGNA2012 RDF dataset normalisation algorithms.

Conformance

This library aims to pass the official test suite and conform with the following:

• JSON-LD 1.0, W3C Recommendation, 2014-01-16, and any errata
• JSON-LD 1.0 Processing Algorithms and API, W3C Recommendation, 2014-01-16, and any errata
• JSON-LD 1.1, W3C Candidate Recommendation, 2019-12-12 or newer JSON-LD latest
• JSON-LD 1.1 Processing Algorithms and API, W3C Candidate Recommendation, 2019-12-12 or newer JSON-LD Processing Algorithms and API latest
• JSON-LD Framing 1.1 W3C Candidate Recommendation 2019-12-12 or newer

Current JSON-LD 1.1 Conformance Status

This library provides comprehensive support of JSON-LD 1.1 specification, except in the areas mentioned below:

Expansion

Good coverage.

Compaction

Good coverage, except:

• @included directive not supported

RDF Serialization/Deserialization

Good coverage, except:

• partial support for JSON literals (@json)
• rdfDirection option is not yet supported (including i18n-datatype and compound-literal forms)

HTML based processing

Not supported.

Current JSON-LD 1.1 Framing Conformance Status

Not supported. The current implementation is still based on an earlier version of JSON-LD 1.1 Framing specification.

Official 1.1 Test Suite

As of April 4th, 2020:

• 92.3% of tests from the official JSON-LD test suite pass.
• all RDF Dataset Normalisation tests from the current test suite pass

Examples

Expand

See complete code in examples/expand.go.

proc := ld.NewJsonLdProcessor()
options := ld.NewJsonLdOptions("")

// expanding remote document

expanded, err := proc.Expand("http://json-ld.org/test-suite/tests/expand-0002-in.jsonld", options)
if err != nil {
	log.Println("Error when expanding JSON-LD document:", err)
	return
}

// expanding in-memory document

doc := map[string]interface{}{
	"@context": "http://schema.org/",
	"@type": "Person",
	"name": "Jane Doe",
	"jobTitle": "Professor",
	"telephone": "(425) 123-4567",
	"url": "http://www.janedoe.com",
}

expanded, err = proc.Expand(doc, options)

Compact

See complete code in examples/compact.go.

proc := ld.NewJsonLdProcessor()
options := ld.NewJsonLdOptions("")

doc := map[string]interface{}{
	"@id": "http://example.org/test#book",
	"http://example.org/vocab#contains": map[string]interface{}{
		"@id": "http://example.org/test#chapter",
	},
	"http://purl.org/dc/elements/1.1/title": "Title",
}

context := map[string]interface{}{
	"@context": map[string]interface{}{
		"dc": "http://purl.org/dc/elements/1.1/",
		"ex": "http://example.org/vocab#",
		"ex:contains": map[string]interface{}{
			"@type": "@id",
		},
	},
}

compactedDoc, err := proc.Compact(doc, context, options)

Flatten

See complete code in examples/flatten.go.

proc := ld.NewJsonLdProcessor()
options := ld.NewJsonLdOptions("")

doc := map[string]interface{}{
	"@context": []interface{}{
		map[string]interface{}{
			"name": "http://xmlns.com/foaf/0.1/name",
			"homepage": map[string]interface{}{
				"@id": "http://xmlns.com/foaf/0.1/homepage",
				"@type": "@id",
			},
		},
		map[string]interface{}{
			"ical": "http://www.w3.org/2002/12/cal/ical#",
		},
	},
	"@id": "http://example.com/speakers#Alice",
	"name": "Alice",
	"homepage": "http://xkcd.com/177/",
	"ical:summary": "Alice Talk",
	"ical:location": "Lyon Convention Centre, Lyon, France",
}

flattenedDoc, err := proc.Flatten(doc, nil, options)

Frame

See complete code in examples/frame.go.

proc := ld.NewJsonLdProcessor()
options := ld.NewJsonLdOptions("")

doc := map[string]interface{}{
	"@context": map[string]interface{}{
		"dc": "http://purl.org/dc/elements/1.1/",
		"ex": "http://example.org/vocab#",
		"ex:contains": map[string]interface{}{"@type": "@id"},
	},
	"@graph": []interface{}{
		map[string]interface{}{
			"@id": "http://example.org/test/#library",
			"@type": "ex:Library",
			"ex:contains": "http://example.org/test#book",
		},
		map[string]interface{}{
			"@id": "http://example.org/test#book",
			"@type": "ex:Book",
			"dc:contributor": "Writer",
			"dc:title": "My Book",
			"ex:contains": "http://example.org/test#chapter",
		},
		map[string]interface{}{
			"@id": "http://example.org/test#chapter",
			"@type": "ex:Chapter",
			"dc:description": "Fun",
			"dc:title": "Chapter One",
		},
	},
}

frame := map[string]interface{}{
	"@context": map[string]interface{}{
		"dc": "http://purl.org/dc/elements/1.1/",
		"ex": "http://example.org/vocab#",
	},
	"@type": "ex:Library",
	"ex:contains": map[string]interface{}{
		"@type": "ex:Book",
		"ex:contains": map[string]interface{}{
			"@type": "ex:Chapter",
		},
	},
}

framedDoc, err := proc.Frame(doc, frame, options)

To RDF

See complete code in examples/to_rdf.go.

proc := ld.NewJsonLdProcessor()
options := ld.NewJsonLdOptions("")
options.Format = "application/n-quads"

// this JSON-LD document was taken from http://json-ld.org/test-suite/tests/toRdf-0028-in.jsonld
doc := map[string]interface{}{
	"@context": map[string]interface{}{
		"sec":        "http://purl.org/security#",
		"xsd":        "http://www.w3.org/2001/XMLSchema#",
		"rdf":        "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
		"dc":         "http://purl.org/dc/terms/",
		"sec:signer": map[string]interface{}{"@type": "@id"},
		"dc:created": map[string]interface{}{"@type": "xsd:dateTime"},
	},
	"@id":                "http://example.org/sig1",
	"@type":              []interface{}{"rdf:Graph", "sec:SignedGraph"},
	"dc:created":         "2011-09-23T20:21:34Z",
	"sec:signer":         "http://payswarm.example.com/i/john/keys/5",
	"sec:signatureValue": "OGQzNGVkMzVm4NTIyZTkZDYMmMzQzNmExMgoYzI43Q3ODIyOWM32NjI=",
	"@graph": map[string]interface{}{
		"@id":      "http://example.org/fact1",
		"dc:title": "Hello World!",
	},
}
triples, err := proc.ToRDF(doc, options)

From RDF

See complete code in examples/from_rdf.go.

proc := ld.NewJsonLdProcessor()
options := ld.NewJsonLdOptions("")

triples := `
	<http://example.com/Subj1> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://example.com/Type> .
	<http://example.com/Subj1> <http://example.com/prop1> <http://example.com/Obj1> .
	<http://example.com/Subj1> <http://example.com/prop2> "Plain" .
	<http://example.com/Subj1> <http://example.com/prop2> "2012-05-12"^^<http://www.w3.org/2001/XMLSchema#date> .
	<http://example.com/Subj1> <http://example.com/prop2> "English"@en .
`

doc, err := proc.FromRDF(triples, options)

Normalize

See complete code in examples/normalize.go.

proc := ld.NewJsonLdProcessor()
options := ld.NewJsonLdOptions("")
options.Format = "application/n-quads"
options.Algorithm = "URDNA2015"

doc := map[string]interface{}{
	"@context": map[string]interface{}{
		"ex": "http://example.org/vocab#",
	},
	"@id": "http://example.org/test#example",
	"@type": "ex:Foo",
	"ex:embed": map[string]interface{}{
		"@type": "ex:Bar",
	},
}

normalizedTriples, err := proc.Normalize(doc, options)

Inspiration

This implementation was influenced by Ruby JSON-LD reader/writer, JSONLD-Java with some techniques borrowed from PyLD and gojsonld. Big thank you to the contributors of the aforementioned libraries for figuring out implementation details of the core algorithms.

History

The original library was written by Stan Nazarenko (@kazarena). See the full list of contributors here.