Readme.md

RDF-Retrieval

This is a javascript library for both Node and the Browser. The library provides functionality for retrieving RDF resources in a format of choice, and for conversions between RDF formats. A custom fetch function can be set (currently only for retrieval of remote resources). This enables retrieval in cases where authentication is required.

Resource retrieval functions

Function	parameters	return
getResourceAsQuadStream	path (string)	Promise<RDF.Stream<RDF.Quad>>
getResourceAsQuadArray	path (string)	Promise<RDF.Quad[]>
getResourceAsDataset	path (string)	Promise<Dataset>
getResourceAsStore	path (string)	Promise<N3.Store <RDF.Quad, N3.Quad>>
getResourceAsTextStream	path (string), format? (string)	Promise<NodeJS.ReadableStream>
getResourceAsString	path (string), format? (string)	Promise<String>

RDF Conversion functions.

The conversion functions are only available for parameters of the type RDF.Stream and RDF.Quad[]

Quad Stream conversions

Function	parameters	return
quadStreamToQuadArray	RDF.Stream	Promise<RDF.Quad[]>
quadStreamToStore	RDF.Stream	Promise<N3.Store<RDF.Quad, N3.Quad>>
quadStreamToDataset	RDF.Stream	Promise<Dataset>
quadStreamToTextStream	RDF.Stream, format? (string)	Promise<NodeJS.ReadableStream>
quadStreamToString	RDF.Stream, format? (string)	Promise<String>

Quad Array conversions

Function	parameters	return
quadArrayToQuadStream	RDF.Quad[]	Promise<RDF.Stream<RDF.Quad>>
quadArrayToStore	RDF.Quad[]	Promise<N3.Store<RDF.Quad, N3.Quad>>
quadArrayToDataset	RDF.Quad[]	Promise<Dataset>
quadArrayToTextStream	RDF.Quad[], format? (string)	Promise<NodeJS.ReadableStream>
quadArrayToString	RDF.Quad[], format? (string)	Promise<String>

Setting custom fetch function

A fetch function can be set using

import * as f from "@dexagod/rdf-retrieval"
await f.setFetchFunction(myCustomFetch)

This function allows fetch functions that provide the same interface as the browser fetch function. (and the headers.content_type header should be available for correct parsing of the resource)

Examples

Setting a custom fetch function for solid

import * as f from "@dexagod/rdf-retrieval"
const auth = require('solid-auth-client');
const fetch = auth.fetch

// setting custom fetch function
await f.setFetchFunction(auth.fetch)

// retrieve remote solid resource
const res = await f.getResourceAsString("https://solidpod.inrupt.net/private/myprivateresource.jsonld", "text/turtle")
console.log('Retrieved resource in turtle format: ', res)

Getting the quads of a remote resource

import * as f from "@dexagod/rdf-retrieval"
const quads = await f.getResourceAsQuadArray("https://myWebsite.org/myResource.ttl")

Converting quads into a stream of quads

import * as f from "@dexagod/rdf-retrieval"
const quads = await f.getResourceAsQuadArray("https://myWebsite.org/myResource.ttl")
// conversion
const stream = await quadArrayToQuadStream(quads);

Converting quad stream into a formatted string

import * as f from "@dexagod/rdf-retrieval"
const stream = await f.getResourceAsQuadStream("https://myWebsite.org/myResource.ttl")
// conversion to jsonld string
const string = await quadStreamToString(stream, "application/ld+json");