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");