LivePresence class

new LivePresence(props: IDataObjectProps<{ Events: ILivePresenceEvents<TData> }>)

Parameters

boolean disposed

Property Value

Number of seconds without a presence update before a remote user is considered offline.

number expirationPeriod

Property Value

The objects fluid type factory.

static factory: DataObjectFactory<LivePresence<object>, DataObjectTypes>

Property Value

Handle to a data store

IFluidHandle<this> handle

Property Value

string id

Property Value

IFluidHandle<this> IFluidHandle

Property Value

this IFluidLoadable

Property Value

this IFluidRouter

Property Value

The initialization status of the data object.

LiveDataObjectInitializeState initializeState

Property Value

Flag that indicates whether initialization has succeeded or not.

boolean isInitialized

Property Value

Local LivePresenceUser. Can be undefined before LivePresence is initialized.

LivePresenceUser<TData> | undefined localUser

Property Value

The objects fluid type/name.

static TypeName: "@microsoft/live-share:LivePresence" = "@microsoft/live-share:LivePresence"

Property Value

Alias for emitter.on(eventName, listener).

addListener: TypedEventTransform<LivePresence<TData>, ILivePresenceEvents<TData> & IEvent>

Property Value

Inherited From LiveDataObject.addListener

Alias for emitter.removeListener().

off: TypedEventTransform<LivePresence<TData>, ILivePresenceEvents<TData> & IEvent>

Property Value

Inherited From LiveDataObject.off

Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.on('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

on: TypedEventTransform<LivePresence<TData>, ILivePresenceEvents<TData> & IEvent>

Property Value

Inherited From LiveDataObject.on

Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

server.once('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

once: TypedEventTransform<LivePresence<TData>, ILivePresenceEvents<TData> & IEvent>

Property Value

Inherited From LiveDataObject.once

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

prependListener: TypedEventTransform<LivePresence<TData>, ILivePresenceEvents<TData> & IEvent>

Property Value

Inherited From LiveDataObject.prependListener

Adds a one-time listener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

prependOnceListener: TypedEventTransform<LivePresence<TData>, ILivePresenceEvents<TData> & IEvent>

Property Value

Inherited From LiveDataObject.prependOnceListener

Removes the specified listener from the listener array for the event named eventName.

const callback = (stream) => {
  console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);

removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events behave as expected.

import { EventEmitter } from 'node:events';
class MyEmitter extends EventEmitter {}
const myEmitter = new MyEmitter();

const callbackA = () => {
  console.log('A');
  myEmitter.removeListener('event', callbackB);
};

const callbackB = () => {
  console.log('B');
};

myEmitter.on('event', callbackA);

myEmitter.on('event', callbackB);

// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
//   A
//   B

// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
//   A

Because listeners are managed using an internal array, calling this will change the position indexes of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

import { EventEmitter } from 'node:events';
const ee = new EventEmitter();

function pong() {
  console.log('pong');
}

ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);

ee.emit('ping');
ee.emit('ping');

Returns a reference to the EventEmitter, so that calls can be chained.

removeListener: TypedEventTransform<LivePresence<TData>, ILivePresenceEvents<TData> & IEvent>

Property Value

Inherited From LiveDataObject.removeListener

Disposes of the object when its container is disposed of.

function dispose()

Returns the current presence info for a specific user. See LivePresenceUser

function getUser(userId: string): LivePresenceUser<TData> | undefined

Parameters

Returns

The current presence information for the user if they've connected to the space.

Returns the current presence info for a specific client ID. See LivePresenceUser

function getUserForClient(clientId: string): LivePresenceUser<TData> | undefined

Parameters

Returns

The current presence information for the client if they've connected to the space.

Returns a snapshot of the current list of presence objects being tracked. See LivePresenceUser

function getUsers(filter?: PresenceState): LivePresenceUser<TData>[]

Parameters

Returns

Array of presence objects.

Initialize the object to begin sending/receiving presence updates through this DDS.

function initialize(data?: TData, state?: PresenceState, allowedRoles?: UserMeetingRole[]): Promise<void>

Parameters

Returns

a void promise that resolves once complete.

Updates the local user's presence shared data object and/or state.

function update(data?: TData, state?: PresenceState): Promise<void>

Parameters

Returns

a void promise that resolves once the update event has been sent to the server.

Remarks

This will trigger the immediate broadcast of the users presence to all other clients.

Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

Returns true if the event had listeners, false otherwise.

import { EventEmitter } from 'node:events';
const myEmitter = new EventEmitter();

// First listener
myEmitter.on('event', function firstListener() {
  console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
  console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
  const parameters = args.join(', ');
  console.log(`event with parameters ${parameters} in third listener`);
});

console.log(myEmitter.listeners('event'));

myEmitter.emit('event', 1, 2, 3, 4, 5);

// Prints:
// [
//   [Function: firstListener],
//   [Function: secondListener],
//   [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener

function emit<E>(eventName: string | symbol, args: any[]): boolean

Parameters

Returns

Inherited From LiveDataObject.emit

Returns an array listing the events for which the emitter has registered listeners.

import { EventEmitter } from 'node:events';

const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]

function eventNames(): (string | symbol)[]

Returns

Inherited From LiveDataObject.eventNames

Call this API to ensure PureDataObject is fully initialized. Initialization happens on demand, only on as-needed bases. In most cases you should allow factory/object to decide when to finish initialization. But if you are supplying your own implementation of DataStoreRuntime factory and overriding some methods and need a fully initialized object, then you can call this API to ensure object is fully initialized.

function finishInitialization(existing: boolean): Promise<void>

Parameters

Returns

Inherited From LiveDataObject.finishInitialization

Get the client info for a given clientId

function getClientInfo(clientId: string): Promise<IClientInfo | undefined>

Parameters

Returns

IClientInfo object if the user is known, otherwise it will return undefined

Inherited From LiveDataObject.getClientInfo

static function getDataObject(runtime: IFluidDataStoreRuntime): Promise<PureDataObject<DataObjectTypes>>

Parameters

Returns

Inherited From LiveDataObject.getDataObject

Retrieve Fluid object using the handle get

function getFluidObjectFromDirectory<T>(key: string, directory: IDirectory, getObjectFromDirectory?: (id: string, directory: IDirectory) => IFluidHandle<FluidObject & IFluidLoadable> | undefined): Promise<T | undefined>

Parameters

Returns

Inherited From LiveDataObject.getFluidObjectFromDirectory

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to events.defaultMaxListeners.

function getMaxListeners(): number

Returns

Inherited From LiveDataObject.getMaxListeners

Initializes internal objects and calls initialization overrides. Caller is responsible for ensuring this is only invoked once.

function initializeInternal(existing: boolean): Promise<void>

Parameters

Returns

Inherited From LiveDataObject.initializeInternal

Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

function listenerCount<E>(eventName: string | symbol, listener?: (args: any[]) => void): number

Parameters

Returns

Inherited From LiveDataObject.listenerCount

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]

function listeners<E>(eventName: string | symbol): (args: any[]) => void[]

Parameters

Returns

Inherited From LiveDataObject.listeners

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');

function rawListeners<E>(eventName: string | symbol): (args: any[]) => void[]

Parameters

Returns

Inherited From LiveDataObject.rawListeners

Removes all listeners, or those of the specified eventName.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.

function removeAllListeners<E>(eventName?: string | symbol): this

Parameters

Returns

Inherited From LiveDataObject.removeAllListeners

{@inheritDoc PureDataObject.request}

function request(request: IRequest): Promise<IResponse>

Parameters

Returns

Inherited From LiveDataObject.request

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.

function setMaxListeners(n: number): this

Parameters

Returns

Inherited From LiveDataObject.setMaxListeners

The Symbol.for('nodejs.rejection') method is called in case a promise rejection happens when emitting an event and captureRejections is enabled on the emitter. It is possible to use events.captureRejectionSymbol in place of Symbol.for('nodejs.rejection').

import { EventEmitter, captureRejectionSymbol } from 'node:events';

class MyClass extends EventEmitter {
  constructor() {
    super({ captureRejections: true });
  }

  [captureRejectionSymbol](err, event, ...args) {
    console.log('rejection happened for', event, 'with', err, ...args);
    this.destroy(err);
  }

  destroy(err) {
    // Tear the resource down here.
  }
}

function [captureRejectionSymbol](error: Error, event: string | symbol, args: any[])

Parameters

Inherited From LiveDataObject.[captureRejectionSymbol]