@muze-nl/oldm

Beginner-friendly OLDM package.

This package exports one default oldm object, wires in the N3 parser/writer by default, provides browser bundles, and sets globalThis.oldm.

import oldm from '@muze-nl/oldm'

const context = oldm.context()

For explicit, tree-shakeable imports, use @muze-nl/oldm-core and @muze-nl/oldm-n3 directly:

import oldm, { Collection, one, many } from '@muze-nl/oldm-core'
import { n3Parser, n3PatchWriter, n3Writer } from '@muze-nl/oldm-n3'

const context = oldm({
  parser: n3Parser,
  writer: n3Writer,
  patchWriter: n3PatchWriter
})

Prefix preference

OLDM shortens predicate and type IRIs with the prefixes configured on the context. Prefix declarations found in Turtle input are parser conveniences; they do not decide the JavaScript property names exposed by OLDM.

When multiple prefixes point at the same namespace, client-provided prefixes are preferred over OLDM defaults, and defaults are preferred over prefixes found in a parsed source document. For example, both pim: and space: are common aliases for http://www.w3.org/ns/pim/space#. Since OLDM prefers space for that namespace, profile data using either pim:storage or space:storage is exposed as space$storage in JavaScript.

const context = oldm({
  parser: n3Parser,
  prefixes: {
    space: 'http://www.w3.org/ns/pim/space#'
  }
})

const profile = context.parse(turtle, profileUrl, 'text/turtle')
const me = profile.subjects[`${profileUrl}#me`]

console.log(me.space$storage.id)

Multiple graphs in one context

A context keeps a registry of every parsed graph. Each context.parse() call still returns a Graph for the parsed resource, while the context exposes a combined view over all graphs loaded into that context.

const context = oldm.context()

const profile = context.parse(profileTurtle, profileUrl, 'text/turtle')
const settings = context.parse(settingsTurtle, settingsUrl, 'text/turtle')

profile.get(`${profileUrl}#me`)       // data from only the profile graph
context.get(`${profileUrl}#me`)       // merged data from all graphs
context.graphs                        // [profile, settings]
context.graph(profileUrl)             // profile
context.data                          // combined subject list
context.subjects                      // combined subject map by full URI
context.sources(context.get(`${profileUrl}#me`))
// [profile, settings] when both graphs contain data for that subject
context.sources(context.get(`${profileUrl}#me`), 'vcard$fn')
// [profile] when only the profile graph contains that property

The combined view merges named subjects by IRI and keeps the original graph views separate. context.sources(subject, predicate, value) can be used to inspect which graph contributed a subject, property, or specific property value.

For source-aware writes, use the graph-specific helpers when you know the resource you want to edit:

profile.set(`${profileUrl}#me`, 'vcard$fn', 'Auke')
profile.add(`${profileUrl}#me`, 'schema$knowsAbout', 'Linked Data')
profile.delete(`${profileUrl}#me`, 'schema$knowsAbout', 'Old value')

Or use context-level helpers with an explicit graph:

context.set(`${profileUrl}#me`, 'vcard$fn', 'Auke', { graph: profile })
context.add(`${profileUrl}#me`, 'schema$knowsAbout', 'Solid', { graph: profileUrl })

When no graph is passed, context.set/add/delete() uses a conservative default: the subject's exact graph URL, the subject document URL without a fragment, the only graph that currently contains the subject, the configured defaultGraph, or the only graph in the context. Direct property assignment on a named subject from context.get(...) uses the same resolver, so simple edits can stay object-like:

const me = context.get(`${profileUrl}#me`)
me.vcard$fn = 'Auke'
delete me.vcard$nickname

If there is no obvious source graph, OLDM throws and asks you to choose one explicitly with context.set/add/delete(..., { graph }) or graph.set/add/delete(...).

Solid PATCH output

oldm.context() wires in the N3 patch writer by default. After parsing and editing a graph, call graph.patch() to generate a Solid N3 Patch string instead of a full Turtle document.

const profile = context.parse(profileTurtle, profileUrl, 'text/turtle')
profile.set(`${profileUrl}#me`, 'vcard$fn', 'Auke C.')

const patch = await profile.patch()

Browser bundles

The friendly package provides both a modern ESM bundle and a classic global IIFE bundle.

For modern module scripts:

<script type="module">
  import oldm from 'https://cdn.jsdelivr.net/npm/@muze-nl/oldm/dist/oldm.min.js'

  const context = oldm.context()
</script>

For a classic script tag that creates globalThis.oldm:

<script src="https://cdn.jsdelivr.net/npm/@muze-nl/oldm/dist/oldm.global.min.js"></script>
<script>
  const context = oldm.context()
</script>

License

MIT.