Emitter

Emitter object.

Instantiate this class, or subclass it for easily creating event emitters.

Full name: \Sabre\Event\Emitter
This class implements: \Sabre\Event\EmitterInterface

Inherited methods

on

Subscribe to an event.

public on(string $eventName, callable $callBack, int $priority = 100): mixed

Parameters:

Parameter	Type	Description
`$eventName`	string
`$callBack`	callable
`$priority`	int

once

Subscribe to an event exactly once.

public once(string $eventName, callable $callBack, int $priority = 100): mixed

Parameters:

Parameter	Type	Description
`$eventName`	string
`$callBack`	callable
`$priority`	int

emit

Emits an event.

public emit(string $eventName, array $arguments = [], callable $continueCallBack = null): bool

This method will return true if 0 or more listeners were successfully handled. false is returned if one of the events broke the event chain.

If the continueCallBack is specified, this callback will be called every time before the next event handler is called.

If the continueCallback returns false, event propagation stops. This allows you to use the eventEmitter as a means for listeners to implement functionality in your application, and break the event loop as soon as some condition is fulfilled.

Note that returning false from an event subscriber breaks propagation and returns false, but if the continue-callback stops propagation, this is still considered a 'successful' operation and returns true.

Lastly, if there are 5 event handlers for an event. The continueCallback will be called at most 4 times.

Parameters:

Parameter	Type	Description
`$eventName`	string
`$arguments`	array
`$continueCallBack`	callable

listeners

Returns the list of listeners for an event.

public listeners(string $eventName): callable[]

The list is returned as an array, and the list of events are sorted by their priority.

Parameters:

Parameter	Type	Description
`$eventName`	string

removeListener

Removes a specific listener from an event.

public removeListener(string $eventName, callable $listener): bool

If the listener could not be found, this method will return false. If it was removed it will return true.

Parameters:

Parameter	Type	Description
`$eventName`	string
`$listener`	callable

removeAllListeners

Removes all listeners.

public removeAllListeners(string $eventName = null): mixed

If the eventName argument is specified, all listeners for that event are removed. If it is not specified, every listener for every event is removed.

Parameters:

Parameter	Type	Description
`$eventName`	string

Automatically generated on 2025-03-18