Javascript implementation for COALA IP.
Install
This project is available through npm. To install run
> npm install coalaip --saveLinked Metadata
This project provides tools for structuring metadata, using schema definitions with the ability to set arbitrary properties on type instances. Metadata is translatable to linked-data formats (e.g. IPLD) for persistence to different databases/storage layers.
Module Overview
Core
This module contains the types outlined in the specification. Additional types have been included because types in the specification inherit from them or certain properties expect other types.
Music
This module extends the core module with the following types: MusicAlbum, MusicComposition, MusicGroup, MusicPlaylist, MusicRecording, and MusicRelease.
Getting Started
Some code to get started structuring metadata. In order to persist to a storage layer, consider using Constellate.
Create a Person
const Person = require('coalaip/lib/core').Person
const man = new Person()
man.setGivenName('John')
man.setFamilyName('Smith')
man.setEmail('[email protected]')
man.set('arbitrary', 'value')
// or if the object is already structured
const woman = {
givenName: 'Jane',
familyName: 'Smith',
email: '[email protected]',
arbitrary: 'value'
}
const person = new Person()
person.withData(woman)Access the Person's data
console.log(man.data())
// {
// "@context": "http://schema.org",
// "@type": "Person",
// "givenName": "John",
// "familyName": "Smith",
// "email": "[email protected]",
// "arbitrary": "value"
// }
// or if you want the data canonically ordered...
console.log(man.dataOrdered())
// {
// "@context": "http://schema.org",
// "@type": "Person",
// "arbitrary": "value",
// "email": "[email protected]",
// "familyName": "Smith",
// "givenName": "John"
// }Add/Set sub-instances
addProperty for property that expects an array
setProperty for property that expects a single value
const {
MusicComposition,
MusicGroup,
MusicRecording
} = require('coalaip/lib/music')
// 'member' expects an array of Parties
const group = new MusicGroup()
group.setDescription('descriptive')
group.setName('Beatles')
group.addMember(man)
group.path = '<placeholder group path>'
const composition = new MusicComposition()
// 'composer' expects an array of Parties
composition.addComposer(man)
composition.path = '<placeholder composition path>'
const recording = new MusicRecording()
// 'byArtist' expects an array of MusicGroups
recording.addByArtist(group)
// 'recordingOf' expects a MusicComposition
recording.setRecordingOf(comp)
console.log(recording.data())
// {
// "@context": "http://coalaip.org",
// "@type": "MusicRecording",
// "byArtist": [
// {
// "@context": "http://schema.org",
// "@type": "MusicGroup",
// "name": "Beatles",
// "description": "descriptive",
// "member": [
// {
// "@context": "http://schema.org",
// "@type": "Person",
// "givenName": "John",
// "familyName": "Smith",
// "email": "[email protected]"
// }
// ]
// }
// ],
// "recordingOf": {
// "@context": "http://coalaip.org",
// "@type": "MusicComposition",
// "composer": [
// {
// "@context": "http://schema.org",
// "@type": "Person",
// "givenName": "John",
// "familyName": "Smith",
// "email": "[email protected]"
// }
// ]
// }
// }
// and the ipld...
console.log(recording.ipld())
// {
// "@context": "http://coalaip.org",
// "@type": "MusicRecording",
// "byArtist": [
// {
// "/": "<placeholder group path>"
// }
// ],
// "recordingOf": {
// "/": "<placeholder composition path>"
// }
// }Access sub-instances
instance.subInstances() returns a flattened array with instance and the unique instances nested within instance. To ease handling of metadata in other programs, the instances are ordered based on the other instances they contain.
const metadata = recording.subInstances()
console.log(metadata)
// [man, group, composition, recording]
// (1) man contains no other instances
// (2,3) group and composition contain man
// (4) recording contains composition and group