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WildcardEmitter

This class is an EventEmitter with support for wildcard event handlers.

What this means is that you can emit events like this:

emit('change:firstName')

and listen to this event like this:

on('change:*')

A few notes:

  • Wildcards only work at the end of an event name.
  • Currently you can only use 1 wildcard.
  • Using ":" as a separator is optional, but it's highly recommended to use some kind of separator.

The WildcardEmitter is a bit slower than the regular Emitter. If your code must be very high performance, it might be better to try to use the other emitter. For most usage the difference is negligible though.

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