WildcardEmitter
in package
implements
EmitterInterface
Uses
WildcardEmitterTrait
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 WilcardEmitter is a bit slower than the regular Emitter. If you code must be very high performance, it might be better to try to use the other emitter. For must usage the difference is negligible though.
Tags
Interfaces, Classes and Traits
- EmitterInterface
- Event Emitter Interface.
Table of Contents
- $listenerIndex : mixed
- An index of listeners for a specific event name. This helps speeding up emitting events after all listeners have been set.
- $listeners : mixed
- The list of listeners.
- $wildcardListeners : mixed
- The list of "wildcard listeners".
- emit() : bool
- Emits an event.
- listeners() : array<string|int, callable>
- Returns the list of listeners for an event.
- on() : mixed
- Subscribe to an event.
- once() : mixed
- Subscribe to an event exactly once.
- removeAllListeners() : mixed
- Removes all listeners.
- removeListener() : bool
- Removes a specific listener from an event.
Properties
$listenerIndex
An index of listeners for a specific event name. This helps speeding up emitting events after all listeners have been set.
protected
mixed
$listenerIndex
= []
If the list of listeners changes though, the index clears.
$listeners
The list of listeners.
protected
mixed
$listeners
= []
$wildcardListeners
The list of "wildcard listeners".
protected
mixed
$wildcardListeners
= []
Methods
emit()
Emits an event.
public
emit(string $eventName[, array<string|int, mixed> $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
- $eventName : string
- $arguments : array<string|int, mixed> = []
- $continueCallBack : callable = null
Return values
bool —listeners()
Returns the list of listeners for an event.
public
listeners(string $eventName) : array<string|int, callable>
The list is returned as an array, and the list of events are sorted by their priority.
Parameters
- $eventName : string
Return values
array<string|int, callable> —on()
Subscribe to an event.
public
on(string $eventName, callable $callBack[, int $priority = 100 ]) : mixed
Parameters
- $eventName : string
- $callBack : callable
- $priority : int = 100
Return values
mixed —once()
Subscribe to an event exactly once.
public
once(string $eventName, callable $callBack[, int $priority = 100 ]) : mixed
Parameters
- $eventName : string
- $callBack : callable
- $priority : int = 100
Return values
mixed —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
- $eventName : string = null
Return values
mixed —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
- $eventName : string
- $listener : callable