A Comunica engine for query evaluation over Solid data pods
npm install @comunica/query-sparql-solid
Comunica SPARQL Solid is a SPARQL query engine for JavaScript that can query over Solid data pods.
This package is safe to use in both Node.js and browser environments.
This module is part of the Comunica framework.
Click here to learn more about Comunica and Solid.
This library has the following known issues in certain cases, that are out of our control (but have been reported).
* Web Workers: This library can not be used within Web Workers due to an open issue in https://github.com/inrupt/solid-client-authn-js/issues/1657 Until this issue is fixed, https://github.com/rubensworks/solid-client-authn-js can be used instead.
* Enterprise Solid Server (https://pod.inrupt.com/):
* Patch requests are not accepted, so only new documents can be created, but existing ones can not be modified.
* Due to missing Accept-Patch, and Accept-Put headers, the destination type has to be forced. This will only work for creating new documents via the putLdp destination type. Updating existing documents via patchSparqlUpdate are currently not possible because of the previous issue.
No issues are known with the Community Solid Server
``bash`
$ yarn add @comunica/query-sparql-solid
or
`bash`
$ npm install -g @comunica/query-sparql-solid
Show 100 triples from a private resource
by authenticating through the https://solidcommunity.net/ identity provider (when using https://pod.inrupt.com/, your IDP will be https://broker.pod.inrupt.com/):
`bash`
$ comunica-sparql-solid --idp https://solidcommunity.net/ \
http://example.org/private-resource.ttl \
"SELECT * WHERE {
?s ?p ?o
} LIMIT 100"
This command will connect with the given identity provider,
and open your browser to log in with your WebID.
After logging in, the query engine will be able to access all the documents you have access to.
Show the help with all options:
`bash`
$ comunica-sparql-solid --help
Just like Comunica SPARQL,
a dynamic variant (comunica-dynamic-sparql-solid) also exists.
_Read more about querying from the command line._
This engine can be used in JavaScript/TypeScript applications as follows:
`javascript
const QueryEngine = require('@comunica/query-sparql-solid').QueryEngine;
const { interactiveLogin } = require('solid-node-interactive-auth');
// This will open your Web browser to log in
const session = await interactiveLogin({ oidcIssuer: 'https://solidcommunity.net/' });
const myEngine = new QueryEngine();
const bindingsStream = await myEngine.queryBindings(
SELECT * WHERE {
?s ?p ?o
} LIMIT 100, {
sources: [session.info.webId], // Sets your profile as query source
'@comunica/actor-http-inrupt-solid-client-authn:session': session,
});
// Consume results as a stream (best performance)
bindingsStream.on('data', (binding) => {
console.log(binding.toString()); // Quick way to print bindings for testing
console.log(binding.has('s')); // Will be true
// Obtaining values
console.log(binding.get('s').value);
console.log(binding.get('s').termType);
console.log(binding.get('p').value);
console.log(binding.get('o').value);
});
bindingsStream.on('end', () => {
// The data-listener will not be called anymore once we get here.
});
bindingsStream.on('error', (error) => {
console.error(error);
});
// Consume results as an array (easier)
const bindings = await bindingsStream.toArray();
console.log(bindings[0].get('s').value);
console.log(bindings[0].get('s').termType);
`
Note that solid-node-interactive-auth only works within Node.js apps. Please refer to @inrupt/solid-client-authn-browser if yoyou want to login via a browser app.
_Read more about querying an application._
Start a webservice exposing a private resource via the SPARQL protocol, i.e., a _SPARQL endpoint_,
by authenticating through the https://solidcommunity.net/ identity provider.
`bash`
$ comunica-sparql-solid-http --idp https://solidcommunity.net/ \
http://example.org/private-resource.ttl
Show the help with all options:
`bash`
$ comunica-sparql-solid-http --help
The SPARQL endpoint can only be started dynamically.
An alternative config file can be passed via the COMUNICA_CONFIG environment variable.
Use bin/http.js` when running in the Comunica monorepo development environment.