EventEmitter - Documentation

new EventEmitter()

Minimal EventEmitter interface that is molded against the Node.js EventEmitter interface.

Source:

events.js, line 105

Methods

emit(event) → {Boolean}

Calls each of the listeners registered for a given event.

Source:

events.js, line 179

Parameters:

Name	Type	Description
`event`	`String` \| `Symbol`	The event name.

Returns:

Type:: Boolean

true if the event had listeners, else false.

eventNames() → {Array}

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

Source:

events.js, line 117

Returns:

Type:: Array

listenerCount(event) → {Number}

Return the number of listeners listening to a given event.

Source:

events.js, line 163

Parameters:

Name	Type	Description
`event`	`String` \| `Symbol`	The event name.

Returns:

Type:: Number

The number of listeners.

listeners(event) → {Array}

Return the listeners registered for a given event.

Source:

events.js, line 142

Parameters:

Name	Type	Description
`event`	`String` \| `Symbol`	The event name.

Returns:

Type:: Array

The registered listeners.

on(event, fn, contextopt) → {EventEmitter}

Add a listener for a given event.

Source:

events.js, line 265

Parameters:

Name	Type	Attributes	Default	Description
`event`	`String` \| `Symbol`			The event name.
`fn`	`function`			The listener function.
`context`	`*`	<optional>	this	The context to invoke the listener with.

Returns:

Type:: EventEmitter

this.

once(event, fn, contextopt) → {EventEmitter}

Add a one-time listener for a given event.

Source:

events.js, line 278

Parameters:

Name	Type	Attributes	Default	Description
`event`	`String` \| `Symbol`			The event name.
`fn`	`function`			The listener function.
`context`	`*`	<optional>	this	The context to invoke the listener with.

Returns:

Type:: EventEmitter

this.

removeAllListeners(eventopt) → {EventEmitter}

Remove all listeners, or those of the specified event.

Source:

events.js, line 345

Parameters:

Name	Type	Attributes	Description
`event`	`String` \| `Symbol`	<optional>	The event name.

Returns:

Type:: EventEmitter

this.

removeListener(event, fn, context, once) → {EventEmitter}

Remove the listeners of a given event.

Source:

events.js, line 292

Parameters:

Name	Type	Description
`event`	`String` \| `Symbol`	The event name.
`fn`	`function`	Only remove the listeners that match this function.
`context`	`*`	Only remove the listeners that have this context.
`once`	`Boolean`	Only remove one-time listeners.

Returns:

Type:: EventEmitter

this.