A JSON-LD processor for Go
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README.md

JSON-goLD

This library is an implementation of the JSON-LD 1.0 specification in Go. It supports both URDNA2015 and URGNA2012 RDF dataset normalisation algorithms.

MAINTAINER CHANGE NOTIFICATION

We are planning to add new features to this library, including support for Linked Data Signatures, content-addressable JSON-LD, etc. In order to facilitate this development, the maintainer of JSON-goLD (@kazarena) is going to copy this repository to the GitHub organisation of his company (@piprate). See the details and further discussion here. Feedback welcome.

Testing & Compliance

As of December 1, 2017:

Inspiration

This implementation was heavily influenced by JSONLD-Java with some techniques borrowed from PyLD and gojsonld. Big thank you to the contributors of the forementioned libraries for figuring out implementation details of the core algorithms.

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/nquads"

// 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/nquads"
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)