Optional updatesPerSecond: numberNext networkId, equivalent to .length of properties
Next userId, equivalent to .length of users
Contains object transforms of all networked objects
Unused networkIds less than nextNetworkId
Unused userIds less than nextUserId
Number of server updates required per second
Default 30.
Needs to be set in the constructor, later changes will not affect the update rate
Contains the object ids and any other data belonging to each user
Contains write permission flags
Static Readonly captureValue: Symbol.for('nodejs.rejection')
See how to write a custom rejection handler.
v13.4.0, v12.16.0
Static captureValue: boolean
Change the default captureRejections option on all new EventEmitter objects.
v13.4.0, v12.16.0
Static defaultBy default, a maximum of 10 listeners can be registered for any single
event. This limit can be changed for individual EventEmitter instances
using the emitter.setMaxListeners(n) method. To change the default
for allEventEmitter instances, the events.defaultMaxListenersproperty can be used. If this value is not a positive number, a RangeErroris thrown.
Take caution when setting the events.defaultMaxListeners because the
change affects allEventEmitter instances, including those created before
the change is made. However, calling emitter.setMaxListeners(n) still has
precedence over events.defaultMaxListeners.
This is not a hard limit. The EventEmitter instance will allow
more listeners to be added but will output a trace warning to stderr indicating
that a "possible EventEmitter memory leak" has been detected. For any singleEventEmitter, the emitter.getMaxListeners() and emitter.setMaxListeners()methods can be used to
temporarily avoid this warning:
import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.setMaxListeners(emitter.getMaxListeners() + 1);
emitter.once('event', () => {
// do stuff
emitter.setMaxListeners(Math.max(emitter.getMaxListeners() - 1, 0));
});
The --trace-warnings command-line flag can be used to display the
stack trace for such warnings.
The emitted warning can be inspected with process.on('warning') and will
have the additional emitter, type, and count properties, referring to
the event emitter instance, the event's name and the number of attached
listeners, respectively.
Its name property is set to 'MaxListenersExceededWarning'.
v0.11.2
Static Readonly errorThis symbol shall be used to install a listener for only monitoring 'error'events. Listeners installed using this symbol are called before the regular'error' listeners are called.
Installing a listener using this symbol does not change the behavior once an'error' event is emitted. Therefore, the process will still crash if no
regular 'error' listener is installed.
v13.6.0, v12.17.0
Private #addPrivate #emitPrivate #setInternal function to set a single object's transform.
Warning: This function does not check write permissions.
Object index
A src array for the transform
Where to start reading in transform
Alias for emitter.on(eventName, listener).
Rest ...args: any[]v0.1.26
Add networked objects to internal objects storage and set the write permission for these objects accordingly.
Initial transform of the object
Mask of which users are allowed to write the transforms of the objects
The networkIds for the new objects
Call this function if you want to disconnect a player from your server. This will close the underlying websocket and WebRTC connection and then trigger the onUserLeave callback, so you don't need to handle this case different from your normal user leave flow.
{string} peer id of the client to disconnect
Synchronously calls each of the listeners registered for the event namedeventName, 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
Rest ...args: any[]v0.1.26
Returns an array listing the events for which the emitter has registered
listeners. The values in the array are strings or Symbols.
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) ]
v6.0.0
Returns the current max listener value for the EventEmitter which is either
set by emitter.setMaxListeners(n) or defaults to defaultMaxListeners.
v1.0.0
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.
The name of the event being listened for
Optional listener: FunctionThe event handler function
v3.2.0
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] ]
v0.1.26
Alias for emitter.removeListener().
Rest ...args: any[]v10.0.0
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 eventNameand 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. Theemitter.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
The name of the event.
The callback function
Rest ...args: any[]v0.1.101
Function which will be called whenever a player starts or stops speaking You are free to add your own logic, for example sending an event to the clients and display a speaking identifier there.
{PeerBase}
{boolean}
Called when data is received from one user via the RTCDataChannel. This function is usually not touched, as the logic remains the same for every server. If the timestamp from the message is higher that the user's lastMessageTimestamp, we set the internal transforms with the user mask, which are the first 4 bytes of the provided ArrayBuffer, reserved for the U32 timestamp, then it's always 4 bytes * number of objects, which hold the object id and 8 * 4 * count bytes for the object's transforms represented by dual quaternion, where the first 4 are the rotation and the second 4 are the translation.
For example, with a ArrayBuffer holding 2 objects, We will call S = TimeStampBytes, I1 = objectId 1 bytes, I2 = objectId 2 bytes, T1 = translation of object 1 and T2 = translations of object 2, the array buffer content would look like this: [SSSS.I1I1I1I1.I2I2I2I2.T1T1T1T1.T1T1T1T1.T1T1T1T1.T1T1T1T1.T1T1T1T1. T1T1T1T1.T1T1T1T1.T1T1T1T1.T2T2T2T2.T2T2T2T2.T2T2T2T2.T2T2T2T2.T2T2T2T2 T2T2T2T2.T2T2T2T2.T2T2T2T2]
{User}
{ArrayBuffer}
Called when a user wants to join. This function should handle the creation of transforms and forwarding them to the instance's addUser event. Below is an example code:
onUserJoin(e:JoinEvent){
let objectCount = 1;
// we have 2 objects, one for the head, and the other one for the body
if (e.data.body) {
objectCount +=1;
}
e.transforms = new Float32Array(8 * objectCount);
for (let i = 0; i < objectCount; ++i) {
e.transforms[i * 8 + 3] = 1;
}
const user = super.onUserJoin(e);
console.log('Joined:', e.peer.id);
// let all other users know that a player joined
const otherUsers = Array.from(this.users.values()).filter(
(u) => u.id != user.id
);
this.sendEvent(
'user-joined',
{ networkIds: user.objects, id: user.id },
otherUsers
);
// set id of the user to the internal used id,
this.sendEvent('set-id', { id: user.id }, [user]);
// now send a user joined event for each already connected user we want to
// track
for (const u of this.users.values()) {
if (u.id == user.id) continue;
this.sendEvent('user-joined', { networkIds: u.objects, id: u.id }, [
user,
]);
}
return user;
}
On the client side, the event handler for the user-joined event would look like this
onEvent(e) {
switch (e.type) {
case 'user-joined':
console.log('Spawning', e);
// here we add 2 new objects to the scene with our
// previously defined player mesh and player body meshes and materials
const head = this.engine.scene.addObject();
head.addComponent('mesh', {
mesh: this.playerMesh,
material: this.playerMaterial,
});
head.addComponent('networked', {
networkId: e.data.networkIds[0],
mode: 'receive',
});
const body = this.engine.scene.addObject();
body.addComponent('mesh', {
mesh: this.playerBodyMesh,
material: this.playerBodyMaterial,
});
body.addComponent('networked', {
networkId: e.data.networkIds[0],
mode: 'receive',
});
const userObjects = {
head: {
object: head,
id: e.data.networkIds[0],
},
body: {
object: body,
id: e.data.networkIds[1]
}
};
// to be able to delete the objects later
// we need to keep a reference to them
this.remoteUsers.set(e.data.id, userObjects);
break;
case 'user-left':
console.log('Player left:', e);
const remoteUser = this.remoteUsers.get(e.data.id);
Object.values(remoteUser).forEach(({object, id}) => {
networkManager.removeObject(id);
object.destroy();
});
break;
default:
console.log('Unknown event:', e);
}
}
Information about the user that is joining
A new user or null if user is not allowed to join
Called when a user left. Here you should clean up any resource. Usually you
should also notify the remaining players that the user has left. For general
clean up, you can use this class's onUserLeave function via supre,
which calls {@link MultiUserServer.removeUser} function and deletes the user and his tracked objects from the internal storage. FOr example:
onUserLeave(e: LeaveEvent){
const id = e.user.id;
const networkIds = e.user.objects;
super.onUserLeave(e);
this.sendEvent(
'user-left',
{ networkIds, id },
Array.from(this.users.values())
);
}
On the client side you would need to implement an event listener for the
user-leave event and remove all the object which belong to the user from
the network manager and also from the scene
Information about the user that left
Called when a custom event was sent from the client via websockets
to the server. Here the custom game logic and event handling should be implemented
by the custom server. For example in this case, if the client sends
a custom WebSocketEvent with the type send-message and the
data: {message: 'example message}, this message will be broadcasted
to the clients
onWsMessageEvent(e: WebSocketEvent, peer: PeerBase) {
switch (e.type) {
case 'send-message':
this.sendEvent(
'receive-message',
{ userId: peer.user?.id, message: e.data.message },
// send event to all users except myself
this.getOtherUsers(peer.user?.id as number)
);
break;
}
}
@param {WebSocketEvent} e The event @param {PeerBase} peer The peer from whom the event was sent
Adds a one-timelistener 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. Theemitter.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
The name of the event.
The callback function
Rest ...args: any[]v0.3.0
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 eventNameand 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.
The name of the event.
The callback function
Rest ...args: any[]v6.0.0
Adds a one-timelistener 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.
The name of the event.
The callback function
Rest ...args: any[]v6.0.0
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');
v9.4.0
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.
Optional event: string | symbolv0.1.26
Removes the specified listener from the listener array for the event namedeventName.
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 anyremoveListener() or removeAllListeners() calls after emitting and before the last listener finishes execution
will not remove them fromemit() 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 indices 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.
Rest ...args: any[]v0.1.26
Remove a user and all his objects from the internal storage. If we have zero users connected, stop update interval to save server resources.
{User} user object we want to remove
Send a custom event
Name of the event
Custom data to send with the event
Which users to send the event to. Leave empty to send to all users.
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 toInfinity (or 0) to indicate an unlimited number of listeners.
Returns a reference to the EventEmitter, so that calls can be chained.
v0.3.5
Handle a request by user to set objectIds transforms to transforms.
Permission mask of the user setting the transforms, Server for full authority.
NetworkIds of the objects to set
Transformations to set
Called at update rate to update the server world sends queued events via Websockets to each user and also sends the current transforms to each user via RTCDataChannel. Also, we set the audio position for each user, if audio is enabled and an audio buffer exists on the user object.
Usually you should not modify this function, but rather call it in your deriving class via super:
update(){
super.update();
// you can add your custom logic which needs to run every server update
// here
}
Static getReturns a copy of the array of listeners for the event named eventName.
For EventEmitters this behaves exactly the same as calling .listeners on
the emitter.
For EventTargets this is the only way to get the event listeners for the
event target. This is useful for debugging and diagnostic purposes.
import { getEventListeners, EventEmitter } from 'node:events';
{
const ee = new EventEmitter();
const listener = () => console.log('Events are fun');
ee.on('foo', listener);
console.log(getEventListeners(ee, 'foo')); // [ [Function: listener] ]
}
{
const et = new EventTarget();
const listener = () => console.log('Events are fun');
et.addEventListener('foo', listener);
console.log(getEventListeners(et, 'foo')); // [ [Function: listener] ]
}
v15.2.0, v14.17.0
Static listenerA class method that returns the number of listeners for the given eventNameregistered on the given emitter.
import { EventEmitter, listenerCount } from 'node:events';
const myEmitter = new EventEmitter();
myEmitter.on('event', () => {});
myEmitter.on('event', () => {});
console.log(listenerCount(myEmitter, 'event'));
// Prints: 2
The emitter to query
The event name
v0.9.12
Since v3.2.0 - Use listenerCount instead.
Static onimport { on, EventEmitter } from 'node:events';
import process from 'node:process';
const ee = new EventEmitter();
// Emit later on
process.nextTick(() => {
ee.emit('foo', 'bar');
ee.emit('foo', 42);
});
for await (const event of on(ee, 'foo')) {
// The execution of this inner block is synchronous and it
// processes one event at a time (even with await). Do not use
// if concurrent execution is required.
console.log(event); // prints ['bar'] [42]
}
// Unreachable here
Returns an AsyncIterator that iterates eventName events. It will throw
if the EventEmitter emits 'error'. It removes all listeners when
exiting the loop. The value returned by each iteration is an array
composed of the emitted event arguments.
An AbortSignal can be used to cancel waiting on events:
import { on, EventEmitter } from 'node:events';
import process from 'node:process';
const ac = new AbortController();
(async () => {
const ee = new EventEmitter();
// Emit later on
process.nextTick(() => {
ee.emit('foo', 'bar');
ee.emit('foo', 42);
});
for await (const event of on(ee, 'foo', { signal: ac.signal })) {
// The execution of this inner block is synchronous and it
// processes one event at a time (even with await). Do not use
// if concurrent execution is required.
console.log(event); // prints ['bar'] [42]
}
// Unreachable here
})();
process.nextTick(() => ac.abort());
The name of the event being listened for
Optional options: StaticEventEmitterOptionsthat iterates eventName events emitted by the emitter
v13.6.0, v12.16.0
Static onceCreates a Promise that is fulfilled when the EventEmitter emits the given
event or that is rejected if the EventEmitter emits 'error' while waiting.
The Promise will resolve with an array of all the arguments emitted to the
given event.
This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error' event
semantics and does not listen to the 'error' event.
import { once, EventEmitter } from 'node:events';
import process from 'node:process';
const ee = new EventEmitter();
process.nextTick(() => {
ee.emit('myevent', 42);
});
const [value] = await once(ee, 'myevent');
console.log(value);
const err = new Error('kaboom');
process.nextTick(() => {
ee.emit('error', err);
});
try {
await once(ee, 'myevent');
} catch (err) {
console.error('error happened', err);
}
The special handling of the 'error' event is only used when events.once()is used to wait for another event. If events.once() is used to wait for the
'error' event itself, then it is treated as any other kind of event without
special handling:
import { EventEmitter, once } from 'node:events';
const ee = new EventEmitter();
once(ee, 'error')
.then(([err]) => console.log('ok', err.message))
.catch((err) => console.error('error', err.message));
ee.emit('error', new Error('boom'));
// Prints: ok boom
An AbortSignal can be used to cancel waiting for the event:
import { EventEmitter, once } from 'node:events';
const ee = new EventEmitter();
const ac = new AbortController();
async function foo(emitter, event, signal) {
try {
await once(emitter, event, { signal });
console.log('event emitted!');
} catch (error) {
if (error.name === 'AbortError') {
console.error('Waiting for the event was canceled!');
} else {
console.error('There was an error', error.message);
}
}
}
foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!
Optional options: StaticEventEmitterOptionsv11.13.0, v10.16.0
Optional options: StaticEventEmitterOptionsStatic setimport { setMaxListeners, EventEmitter } from 'node:events';
const target = new EventTarget();
const emitter = new EventEmitter();
setMaxListeners(5, target, emitter);
Optional n: numberA non-negative number. The maximum number of listeners per EventTarget event.
Rest ...eventTargets: (EventEmitter | _DOMEventTarget)[]v15.4.0
Generated using TypeDoc
Enable timing out server update iterations if they take too long to compute, defaults to false. If set to true, update iterations will silently timeout and not being processed.
Needs to be set in the constructor, later changes will not affect the update timeout behaviour.