Awesome
@rdfjs/sink-map
Map for RDF/JS Sink including shortcut methods.
Usage
The package provides Map from a string key to a Sink with a shortcut for .import
.
Typical it's used to store parsers or serializers for specific media types.
As SinkMap extends from the ECMAScript 2015 Map and doesn't overload any standard methods, methods like set
, get
, has
or delete
can be used as defined in the specification.
Create a SinkMap
The constructor accepts arrays with key/sink pairs to fill the map:
const map = new SinkMap([
['text/turtle', new ParserN3()]
])
It's also possible to create an empty map and add or extend it later using the .set()
method:
const map = new SinkMap()
map.set('text/turtle') = new ParserN3()
Find a Sink
The .get
method searches for the matching Sink and returns it:
const map = new SinkMap([...])
const sink = map.get('text/turtle')
if (sink) {
// found
} else {
// not found
}
Import shortcut
Usually you want to call the .import
method of the matching Sink.
The map provides a shortcut for this.
It also has a .import
method, but requires additionally the key as the first argument.
It returns null
if no matching sink was found:
const map = new SinkMap([...])
const input = fs.createReadStream('..')
const output = map.import('text/turtle', input)
if (output) {
// found
} else {
// not found
}
Example
Here is a complete example where the map is used to store parsers and the .import
shortcut is used to parse a string input:
import SinkMap from '@rdfjs/sink-map'
import ParserN3 from '@rdfjs/parser-n3'
import { Readable } from 'readable-stream'
const map = new SinkMap([
['text/turtle', new ParserN3()]
])
const input = new Readable({
read: () => {
input.push(`
PREFIX s: <http://schema.org/>
[] a s:Person ;
s:jobTitle "Professor" ;
s:name "Jane Doe" ;
s:telephone "(425) 123-4567" ;
s:url <http://www.janedoe.com> .
`)
input.push(null)
}
})
const output = map.import('text/turtle', input)
output.on('data', quad => {
console.log(`${quad.subject.value} - ${quad.predicate.value} - ${quad.object.value}`)
})