Package net.fabricmc.fabric.api.event

Class Event<T>

java.lang.Object

net.fabricmc.fabric.api.event.Event<T>

Type Parameters:

T - The listener type.

@NonExtendable
public abstract class Event<T>
extends Object

Base class for Fabric's event implementations.

See Also:

• EventFactory

Field Summary

Fields

Modifier and Type	Field	Description
static final Identifier	DEFAULT_PHASE	The identifier of the default phase.
protected T	invoker	The invoker field.

Constructor Summary

Constructors

Constructor	Description
Event()

Method Summary

Modifier and Type	Method	Description
void	addPhaseOrdering(Identifier firstPhase, Identifier secondPhase)	Request that listeners registered for one phase be executed before listeners registered for another phase.
final T	invoker()	Returns the invoker instance.
void	register(Identifier phase, T listener)	Register a listener to the event for the specified phase.
abstract void	register(T listener)	Register a listener to the event, in the default phase.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

invoker

protected volatile T invoker

The invoker field. This should be updated by the implementation to always refer to an instance containing all code that should be executed upon event emission.

DEFAULT_PHASE

public static final Identifier DEFAULT_PHASE

The identifier of the default phase. Have a look at EventFactory.createWithPhases(java.lang.Class<? super T>, java.util.function.Function<T[], T>, net.minecraft.util.Identifier...) for an explanation of event phases.

Constructor Details

Event

public Event()

Method Details

invoker

public final T invoker()

Returns the invoker instance.

An "invoker" is an object which hides multiple registered listeners of type T under one instance of type T, executing them and leaving early as necessary.

Returns:

The invoker instance.

register

public abstract void register(T listener)

Register a listener to the event, in the default phase. Have a look at addPhaseOrdering(net.minecraft.util.Identifier, net.minecraft.util.Identifier) for an explanation of event phases.

Parameters:

listener - The desired listener.

register

public void register(Identifier phase,
 T listener)

Register a listener to the event for the specified phase. Have a look at EventFactory.createWithPhases(java.lang.Class<? super T>, java.util.function.Function<T[], T>, net.minecraft.util.Identifier...) for an explanation of event phases.

Parameters:

phase - Identifier of the phase this listener should be registered for. It will be created if it didn't exist yet.

listener - The desired listener.

addPhaseOrdering

public void addPhaseOrdering(Identifier firstPhase,
 Identifier secondPhase)

Request that listeners registered for one phase be executed before listeners registered for another phase. Relying on the default phases supplied to EventFactory.createWithPhases(java.lang.Class<? super T>, java.util.function.Function<T[], T>, net.minecraft.util.Identifier...) should be preferred over manually registering phase ordering dependencies.

Incompatible ordering constraints such as cycles will lead to inconsistent behavior: some constraints will be respected and some will be ignored. If this happens, a warning will be logged.

Parameters:

firstPhase - The identifier of the phase that should run before the other. It will be created if it didn't exist yet.

secondPhase - The identifier of the phase that should run after the other. It will be created if it didn't exist yet.