modelld

modelld

A JavaScript API for selecting and manipulating subgraphs of linked data.

This is a work in progress! The API will definitely change.

About

modelld is a library which helps you build apps on top linked data. It provides a higher-level interface for graph manipulation than you'd get using something like rdf-ext or rdflib.js out of the box. It also makes it easy to save graphs back to LDP services even if your models are made up of data from several different URIs.

modelld makes working with linked data easier by providing developers with an API for defining their own schemas on top of graphs of data. It's sort of like an ORM but for linked data.

Roadmap

modelld is a work in progress. Don't depend on it for anything.

Here are the things that I'm either actively working on, or that should be worked on in the near future:

• Determine an architecture for handling multiple RDF libraries
  • RDF JS task force API?
  • Dependency injection?
• Support all RDF types

Example

Here's how you might use modelld to model part of a Solid user profile:

import { modelFactory } from 'modelld'
import { vocab, rdflib, web } from 'solid-client'

const profileModel = modelFactory(rdflib, {
  name: vocab.foaf('name'),
  picture: vocab.foaf('img'),
  phone: vocab.foaf('phone')
})

const defaultGraph = 'https://me.databox.me/profile/card'
const webId = 'https://me.databox.me/profile/card#me'
// Suppose you've got an RDF graph named 'graph'
const profile = profileModel(graph, defaultGraph, webId)

// Get the value of some fields
profile.any('phone') // => 'tel:[phone]'
profile.get('phone') // => ['tel:[phone]', 'tel:[phone]']
profile.fields('phone') // => [Field('tel:[phone]'), Field('tel:[phone]')]
// Undeclared fields don't show up
profile.any('undeclared-field') // => undefined
profile.get('undeclared-field') // => []
profile.fields('undeclared-field') // => []

// Add a field.  Models are immutable, so adding/setting/removing fields always
// returns a new model.
const newProfile = profile.add('phone', 'tel:[phone]')
profile.get('phone') // => ['tel:[phone]', 'tel:[phone]']
newProfile.get('phone') // => ['tel:[phone]', 'tel:[phone]', 'tel:[phone]']

// Remove a field
const myName = profile.fields('name')[0]
profile
  .remove(myName)
  .any('name') // => undefined

// Update a field's value
const name = profile.fields('name')[0]
profile
  .set(name, 'Daniel')
  .any('name') // => 'Daniel'

// Update the namedGraph for a field
profile.setAny('name', {namedGraph: 'https://example.com/other-resource'})

// Save a model back to the LDP server(s) it came from
const name = profile.fields('name')[0]
profile
  .set(name, 'Daniel')
  .add('phone', 'tel:[phone]')
  .save(rdflib, web)
  .then(newModel => {
    console.log(newModel.get('name'))
    console.log(newModel.get('phone'))
  })
  .catch(err => {
    // err.model is the model including all the updates which worked
    // err.diffMap describes the RDF statements which should have been inserted and removed from the server
    // err.failedURIs describes the URIs for which the PATCH requests failed
  })

Installing

$ npm install --save modelld