@ldo/subscribable-dataset

A library of RDFJS Datasets that have many uses including subscribing to node changes and making transactions on a dataset.

This library follows the RDFJS spec for a Dataset.

Installation

``bash
npm i @ldo/subscribable-dataset
`

Simple Example

`typescript
import { createSubscribableDataset, DatasetChanges } from "@ldo/subscribable-dataset";
import { Dataset } from "@rdfjs/types";
import { quad, namedNode }from '@ldo/rdf-utils';

const subscribableDataset = createSubscribableDataset([
quad(
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://www.w3.org/1999/02/22-rdf-syntax-ns#type"),
namedNode("http://example.org/cartoons#Firebender")
),
]);
subscribableDataset.on(
namedNode("http://example.org/cartoons#Zuko"),
(currentQuads: Dataset, changes: DatasetChanges) => {
console.log(currentQuads.toString());
console.log("--------");
console.log(changes.added?.toString());
}
);
/*
Prints:
.
"Zuko" .
--------
"Zuko" .
*/
subscribableDataset.add(
quad(
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://example.org/cartoons#name"),
literal("Zuko")
)
);
`

Loading from Serialized Data

`typescript
import { serializedToDataset, serializedToSubscribableDataset } from "@ldo/subscribable-dataset";

async function run(): Promise {
// Create an ExtendedDataset using Turtle
const turtleData =
@prefix : <#>.
@prefix elem: .
@prefix card: .

:this
elem:author card:me.
;
const turtleDataset = await serializedToDataset(turtleData, {
baseIRI:
"https://jackson.solidcommunity.net/IndividualChats/jackson.solidcommunity.net/index.ttl#",
// NOTE: the "format" field isn't required because Turtle is the default parser
});

// Create a SubcribableDataset using JSON-LD
const jsonLdData = [
{
"@id":
"https://jackson.solidcommunity.net/IndividualChats/jackson.solidcommunity.net/index.ttl#this",
"http://purl.org/dc/elements/1.1/author": [
{
"@id": "https://jackson.solidcommunity.net/profile/card#me",
},
],
},
{
"@id": "https://jackson.solidcommunity.net/profile/card#me",
},
];
const jsonLdDataset = await serializedToSubscribableDataset(
JSON.stringify(jsonLdData),
{
baseIRI:
"https://jackson.solidcommunity.net/IndividualChats/jackson.solidcommunity.net/index.ttl#",
format: "application/ld+json",
}
);
// Returns true because the input data describes the same triple.
console.log(turtleDataset.equals(jsonLdDataset));
}
run();
`

Advanced Example

`typescript
import { createSubscribableDataset, DatasetChanges } from "@ldo/subscribable-dataset";
import { quad, namedNode, literal } from '@ldo/rdf-utils';
import { Dataset } from "@rdfjs/types";

// Create an empty subscribable dataset
const subscribableDataset = createSubscribableDataset();
// Add some initial quads
subscribableDataset.addAll([
quad(
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://www.w3.org/1999/02/22-rdf-syntax-ns#type"),
namedNode("http://example.org/cartoons#Firebender"),
namedNode("http://example.org/cartoons")
),
quad(
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://example.org/cartoons#name"),
literal("Zuko"),
namedNode("http://example.org/cartoons")
),
]);
// Set up listeners
// Listener that will trigger whenever a quad containing the named
// node "http://example.org/cartoons#Zuko" is added or removed.
subscribableDataset.on(
namedNode("http://example.org/cartoons#Zuko"),
(zukoQuads: Dataset, changes: DatasetChanges) => {
console.log("ZUKO NODE CHANGED ============");
console.log(zukoQuads.toString());
console.log("Added Quads:");
console.log(changes.added?.toString());
console.log("Removed Quads:");
console.log(changes.removed?.toString());
console.log("\n\n");
}
);
// Listener that will trigger whenever a quad containing the named
// node "http://example.org/cartoons" is added or removed. This is
// useful for keeping track of the cartoons graph.
subscribableDataset.on(
namedNode("http://example.org/cartoons"),
(cartoonGraphQuads: Dataset, changes: DatasetChanges) => {
console.log("CARTOON GRAPH CHANGED ============");
console.log(cartoonGraphQuads.toString());
console.log("Added Quads:");
console.log(changes.added?.toString());
console.log("Removed Quads:");
console.log(changes.removed?.toString());
console.log("\n\n");
}
);

// Modify the dataset
/*
Prints:
CARTOON GRAPH CHANGED ============
.
"Zuko" .
.
"Katara" .

Added Quads:
.
"Katara" .

Removed Quads:
undefined
*/
subscribableDataset.addAll([
quad(
namedNode("http://example.org/cartoons#Katara"),
namedNode("http://www.w3.org/1999/02/22-rdf-syntax-ns#type"),
namedNode("http://example.org/cartoons#Waterbender"),
namedNode("http://example.org/cartoons")
),
quad(
namedNode("http://example.org/cartoons#Katara"),
namedNode("http://example.org/cartoons#name"),
literal("Katara"),
namedNode("http://example.org/cartoons")
),
]);

/*
Prints:
ZUKO NODE CHANGED ============
.
"Zuko" .
.
.

Added Quads:
.
.

Removed Quads:
undefined


CARTOON GRAPH CHANGED ============
.
"Zuko" .
.
.
"Katara" .
.

Added Quads:
.
.

Removed Quads:
undefined
*/
subscribableDataset.addAll([
quad(
namedNode("http://example.org/cartoons#Katara"),
namedNode("http://example.org/cartoons#hasEnemy"),
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://example.org/cartoons")
),
quad(
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://example.org/cartoons#hasEnemy"),
namedNode("http://example.org/cartoons#Katara"),
namedNode("http://example.org/cartoons")
),
]);

// If there are many operation you want to do at once, use transactions.
// An update will not be triggered until the transaction is committed.
const transactionalDataset = subscribableDataset.startTransaction();
// Delete all triples with a "hasEnemy" predicate
transactionalDataset.deleteMatches(
undefined,
namedNode("http://example.org/cartoons#hasEnemy"),
undefined,
undefined
);
// Add "hasFrient" predicate
transactionalDataset.addAll([
quad(
namedNode("http://example.org/cartoons#Katara"),
namedNode("http://example.org/cartoons#hasFriend"),
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://example.org/cartoons")
),
quad(
namedNode("http://example.org/cartoons#Zuko"),
namedNode("http://example.org/cartoons#hasFriend"),
namedNode("http://example.org/cartoons#Katara"),
namedNode("http://example.org/cartoons")
),
]);
/*
Prints:
ZUKO NODE CHANGED ============
.
"Zuko" .
.
.

Added Quads:
.
.

Removed Quads:
.
.


CARTOON GRAPH CHANGED ============
.
"Zuko" .
.
.
"Katara" .
.

Added Quads:
.
.

Removed Quads:
.
.
*/
transactionalDataset.commit();
``

Sponsorship

This project was made possible by a grant from NGI Zero Entrust via nlnet. Learn more on the NLnet project page.

Liscense

MIT