Utilities

The @lark-sh/client package exports several utility functions and constants for working with paths, IDs, and server values.

import {
  generatePushId,
  ServerValue,
  normalizePath,
  joinPath,
  getParentPath,
  getKey,
  isVolatilePath,
} from '@lark-sh/client';

generatePushId

generatePushId(): string

Generates a unique, chronologically-sortable 20-character ID. The format is identical to the keys produced by DatabaseReference.push(). IDs are ordered by time, so items created earlier sort before items created later when using orderByKey().

const id = generatePushId();
// e.g. "-NxK3jR2fHa0YkLm9pQr"

await db.ref(`posts/${id}`).set({
  title: 'My Post',
  createdAt: ServerValue.TIMESTAMP,
});

Use generatePushId() when you need a key before writing, such as when referencing the key in multiple locations within a single update() call.

ServerValue.TIMESTAMP

ServerValue.TIMESTAMP: object

A placeholder value that the server replaces with its current timestamp (milliseconds since the Unix epoch) at the time the write is committed. Use this instead of Date.now() to ensure consistency across clients with different clock offsets.

await db.ref('users/alice').update({
  lastLogin: ServerValue.TIMESTAMP,
});

ServerValue.TIMESTAMP is a sentinel object, not an actual number. It is resolved server-side when the write is processed.

normalizePath

normalizePath(path: string): string

Normalizes a database path by removing double slashes, trailing slashes, and leading slashes.

Parameter	Type	Description
`path`	`string`	The path to normalize.

normalizePath('//users//alice/');
// "users/alice"

normalizePath('/');
// ""

joinPath

joinPath(...segments: string[]): string

Joins one or more path segments with /, producing a normalized path.

Parameter	Type	Description
`...segments`	`string[]`	Path segments to join.

joinPath('users', 'alice', 'profile');
// "users/alice/profile"

joinPath('rooms', 'room1', 'members');
// "rooms/room1/members"

getParentPath

getParentPath(path: string): string

Returns the parent path of the given path. Returns an empty string for top-level paths.

Parameter	Type	Description
`path`	`string`	The path to get the parent of.

getParentPath('users/alice/profile');
// "users/alice"

getParentPath('users');
// ""

getKey

getKey(path: string): string

Returns the last segment of a path (the key).

Parameter	Type	Description
`path`	`string`	The path to extract the key from.

getKey('users/alice/profile');
// "profile"

getKey('users');
// "users"

isVolatilePath

isVolatilePath(path: string, patterns: string[]): boolean

Checks whether a given path matches any of the provided volatile path patterns. Volatile paths are used for high-frequency, low-latency data streams such as cursor positions or live indicators.

Parameter	Type	Description
`path`	`string`	The path to check.
`patterns`	`string[]`	An array of volatile path patterns to match against. Patterns support `*` as a single-segment wildcard.

const patterns = ['cursors/*', 'typing/*'];

isVolatilePath('cursors/alice', patterns);
// true

isVolatilePath('users/alice', patterns);
// false

Getting started

Guides

API reference

generatePushId

ServerValue.TIMESTAMP

normalizePath

joinPath

getParentPath

getKey

isVolatilePath

​generatePushId

​ServerValue.TIMESTAMP

​normalizePath

​joinPath

​getParentPath

​getKey

​isVolatilePath

generatePushId

ServerValue.TIMESTAMP

normalizePath

joinPath

getParentPath

getKey

isVolatilePath