@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
})

Literal values

Use oldm.literal() to construct a value without needing a graph:

const name = oldm.literal('Auke', { language: 'nl-NL' })
const plainName = oldm.literal('Auke', { language: '' })
const birthday = oldm.literal('1972-09-20', {
  type: 'http://www.w3.org/2001/XMLSchema#date'
})
const text = oldm.literal('https://example.org/')

The helper accepts strings and numbers, including boxed values, and returns a fresh boxed value. It copies existing language/type metadata unless overridden and does not modify the input. An explicit empty language is preserved. Supply a full datatype IRI, or expand shorthand explicitly using context.fullURI('xsd$date'). The standalone constructor has no prefix context. URL-shaped text stays a literal when passed to graph write helpers. Use String(value) or Number(value) for the primitive value.

The same helper is available as the named literal export from @muze-nl/oldm-core. Existing graph.setLanguage() calls remain supported, including their in-place behavior for boxed values. Deletion matching is unchanged by the new constructor.

Property prefixes and IRI values

Only property names are shortened. Class values (subject.a) and literal datatypes (value.type, when present) are full IRIs in both source graphs and combined context views. Linked objects retain their full IRI in .id.

Property names in source graphs prefer source prefixes. Combined context views prefer client-provided prefixes, then OLDM defaults, then source prefixes. Namespace aliases, such as OLDM's schema.org HTTP/HTTPS mapping, apply to property-name shortening; value IRIs retain their original namespace.

const context = oldm.context({
  prefixes: { person: 'http://xmlns.com/foaf/0.1/' }
})
const graph = context.parse(turtle, profileUrl, 'text/turtle')
const me = context.get(`${profileUrl}#me`)

me.a // 'http://xmlns.com/foaf/0.1/Person', or an array of class IRIs
const personClass = context.fullURI('person$Person')
oldm.many(me.a).includes(personClass)

graph.set/add/delete() and context write helpers still accept shorthand class inputs. They expand the input once using the receiving graph or context's prefixes. graph.setType() and context.setType() do the same for datatypes. Unresolved shorthand such as missing$Person is rejected at these write boundaries. Relative class/datatype references on a graph resolve against its URL; standalone values and context datatype setters require absolute IRIs. Absolute IRIs, including URNs, are accepted without namespace rewriting.

context.sources(id, 'a', className) accepts a full IRI or shorthand, preferring context prefixes and falling back to non-conflicting source prefixes. Matching compares exact IRIs: HTTP and HTTPS namespaces are distinct. For repeated filtering, expand the requested class once outside the loop.

Source subjects remain ordinary objects. When assigning subject.a or literal metadata directly, supply full IRIs. Context subject assignment still delegates to the context write helpers. Turtle output may use prefixes or relative IRIs without changing the represented value.

URI helpers and relative references

fullURI(value) always returns a valid absolute IRI or throws TypeError. It expands a known prefix by exact string concatenation, preserving the entire suffix, including an empty suffix. Relative references use RFC 3986 base resolution. Absolute inputs are validated without normalization: case, Unicode, percent escapes, and namespace identity are preserved.

shortURI(iri) returns a prefixed spelling, or the unchanged absolute IRI when no prefix matches. It never returns a relative reference or applies namespace aliases. Aliases still apply when mapping predicates to object property names.

relativeURI(iri, baseURI) returns a relative reference only when resolving it against the base reproduces the exact input IRI; otherwise it returns the absolute IRI. The base argument is optional: graph helpers default to graph.baseURI, initially the graph URL without its fragment. Context helpers use the optional baseURI context setting. Without a base, relativeURI retains the absolute IRI, and fullURI rejects relative inputs.

For a graph whose base is https://example.org/data/card, with foo mapped to that same IRI:

graph.fullURI('foo$/child') // 'https://example.org/data/card/child'
graph.fullURI('card/child') // 'https://example.org/data/card/child'
graph.fullURI('/child')     // 'https://example.org/child'
graph.shortURI('https://example.org/data/card/child') // 'foo$/child'
graph.relativeURI('https://example.org/data/card/child') // 'card/child'

An unknown $ prefix throws; use ./price$tag for a relative path that contains $. With : as the separator, an unknown scheme:value can still be a valid absolute IRI (for example urn:example). These API strings have no Turtle angle brackets or backslash escapes.

Both Turtle writers prefer a valid prefixed name, then an exact relative reference, then an absolute IRI. They emit @base explicitly so relative output keeps its meaning when the document is moved. Turtle local-name escaping is handled by the writer: internal foo$/child becomes foo:\/child. N-Triples and N-Quads continue to use absolute IRIs; PATCH output keeps its absolute fallback.

Migrating from shorthand values

Replace comparisons such as many(subject.a).includes('foaf$Person') with a comparison against context.fullURI('foaf$Person'). Compare literal datatypes against full IRIs too. Shape declarations can keep shorthand class/datatype inputs; oldm-shape resolves them against the subject's graph or context.

Pass full datatype IRIs to standalone literal() calls. Existing serialized Turtle needs no migration. Application-owned JSON that contains shorthand class or datatype values must resolve those values with its recorded prefixes when loading. OLDM does not silently rewrite stored application documents.

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.