@bigbluebutton/tlstore

tlstore is a library for creating and managing data.

In this library, a "record" is an object that is stored under a typed id.

tlstore is used by tldraw to store its data.

It is designed to be used with tlstate (@bigbluebutton/tlstate).

Usage

First create types for your records.

interface Book extends BaseRecord<'book'> {
	title: string
	author: ID<Author>
	numPages: number
}

interface Author extends BaseRecord<'author'> {
	name: string
	isPseudonym: boolean
}

Then create your RecordType instances.

const Book = createRecordType<Book>('book')

const Author = createRecordType<Author>('author').withDefaultProperties(() => ({
	isPseudonym: false,
}))

Then create your RecordStore instance.

const store = new RecordStore<Book | Author>()

Then you can create records, add them to the store, update, and remove them.

const tolkeinId = Author.createCustomId('tolkein')

store.put([
	Author.create({
		id: jrrTolkeinId,
		name: 'J.R.R Tolkein',
	}),
])

store.update(tolkeinId, (author) => ({
	...author,
	name: 'DJJ Tolkz',
	isPseudonym: true,
}))

store.remove(tolkeinId)

API

RecordStore

The RecordStore class is the main class of the library.

const store = new RecordStore()

put(records: R[]): void

Add some records to the store. It's an error if they already exist.

const record = Author.create({
	name: 'J.R.R Tolkein',
	id: Author.createCustomId('tolkein'),
})

store.put([record])

update(id: ID<R>, updater: (record: R) => R): void

Update a record. To update multiple records at once, use the update method of the TypedRecordStore class.

const id = Author.createCustomId('tolkein')

store.update(id, (r) => ({ ...r, name: 'Jimmy Tolks' }))

remove(ids: ID<R>[]): void

Remove some records from the store via their ids.

const id = Author.createCustomId('tolkein')

store.remove([id])

get(id: ID<R>): R

Get the value of a store record by its id.

const id = Author.createCustomId('tolkein')

const result = store.get(id)

allRecords(): R[]

Get an array of all values in the store.

const results = store.allRecords()

clear(): void

Remove all records from the store.

store.clear()

has(id: ID<R>): boolean

Get whether the record store has an record stored under the given id.

const id = Author.createCustomId('tolkein')

const result = store.has(id)

serialize(filter?: (record: R) => boolean): RecordStoreSnapshot<R>

Opposite of deserialize. Creates a JSON payload from the record store.

const serialized = store.serialize()

const serialized = store.serialize((record) => record.name === 'J.R.R Tolkein')

deserialize(snapshot: RecordStoreSnapshot<R>): void

Opposite of serialize. Replace the store's current records with records as defined by a simple JSON structure into the stores.

const serialized = { ... }

store.deserialize(serialized)

listen(listener: ((entry: HistoryEntry) => void): () => void

Add a new listener to the store The store will call the function each time the history changes. Returns a function to remove the listener.

store.listen((entry) => doSomethingWith(entry))

mergeRemoteChanges(fn: () => void): void

Merge changes from a remote source without triggering listeners.

store.mergeRemoteChanges(() => {
	store.put(recordsFromRemoteSource)
})

createDerivationCache(name: string, derive: ((record: R) => R | undefined)): DerivationCache<R>

Create a new derivation cache.

const derivationCache = createDerivationCache('popular_authors', (record) => {
	return record.popularity > 62 ? record : undefined
})

RecordType

The RecordType class is used to define the structure of a record.

const recordType = new RecordType('author', () => ({ living: true }))

RecordType instances are most often created with createRecordType.

create(properties: Pick<R, RequiredProperties> & Omit<Partial<R>, RequiredProperties>): R

Create a new record of this type.

const record = recordType.create({ name: 'J.R.R Tolkein' })

clone(record: R): R

Clone a record of this type.

const record = recordType.create({ name: 'J.R.R Tolkein' })

const clone = recordType.clone(record)

createId(): ID<R>

Create an Id for a record of this type.

const id = recordType.createId()

createCustomId(id: string): ID<R>

Create a custom Id for a record of this type.

const id = recordType.createCustomId('tolkein')

isInstance

Check if a value is an instance of this record type.

const record = recordType.create({ name: 'J.R.R Tolkein' })

const result1 = recordType.isInstance(record) // true
const result2 = recordType.isInstance(someOtherRecord) // false

isId

Check if a value is an id for a record of this type.

const id = recordType.createCustomId('tolkein')

const result1 = recordType.isId(id) // true
const result2 = recordType.isId(someOtherId) // false

withDefaultProperties

Create a new record type with default properties.

const youngLivingAuthor = new RecordType('author', () => ({ age: 28, living: true }))

const oldDeadAuthor = recordType.withDefaultProperties({ age: 93, living: false })

RecordStoreQueries

TODO

Helpers

executeQuery

TODO

DerivationCache

The DerivationCache class is used to create a cache of derived records.

const derivationCache = new DerivationCache('popular_authors', (record) => {
	return record.popularity > 62 ? record : undefined
})

createRecordType

A helper used to create a new RecordType instance with no default properties.

const recordType = createRecordType('author'))

assertIdType

A helper used to assert that a value is an id for a record of a given type.

const id = recordType.createCustomId('tolkein')

assertIdType(id, recordType)

Types

ID

A type used to represent a record's id.

const id: ID<Author> = Author.createCustomId('tolkein')

BaseRecord

A BaseRecord is a record that has an id and a type. It is the base type for all records.

type AuthorRecord extends BaseRecord<"author"> {
  name: string
  age: number
  living: boolean
}

AllRecords

A helper to get the type of all records in a record store.

type AllAuthorRecords = AllRecords<RecordStore<Author>>

RecordsDiff

A diff describing the changes to a record.

CollectionDiff

A diff describing the changes to a collection.

License

The source code in this repository (as well as our 2.0+ distributions and releases) are currently licensed under Apache-2.0. These licenses are subject to change in our upcoming 2.0 release. If you are planning to use tldraw in a commercial product, please reach out at [email protected].