====== Listening to Events ======
In this tutorial you will learn to:
  - Understand Events and Callbacks
  - Register a callback for an existing Event

===== Events =====
Events are represented by instances of ''net.fabricmc.fabric.api.event.Event'' which store and call callbacks. Often there is a single event instance for a callback, which is stored in a static field ''EVENT'' of the callback interface, but there are other patterns. For example [[https://github.com/FabricMC/fabric/blob/1.17/fabric-lifecycle-events-v1/src/main/java/net/fabricmc/fabric/api/client/event/lifecycle/v1/ClientTickEvents.java|ClientTickEvents]] groups several related events together.

===== Callbacks =====
Each event has a corresponding callback interface, conventionally named ''EventNameCallback''. Callbacks are registered by calling ''register()'' on an event instance with an instance of the callback interface as the argument.

==== Callback Interfaces in Fabric API ====
All event callback interfaces provided by Fabric API can be found in the ''net.fabricmc.fabric.api.event'' package.
A partial list of existing callbacks is provided at the bottom of this tutorial.

==== Custom Callbacks ====
Although there are plenty of events already provided by Fabric API, you can still make your own events. Please refer to [[tutorial:events]].

===== Practice ======
This example registers an ''AttackBlockCallback'' to damage players when they hit blocks that don't drop when hand-mined. It returns ''<yarn class_1269.field_5811>'' as other callbacks should still be called. See the [[https://github.com/FabricMC/fabric/blob/12865e786ce2102d344304a679b70084be84d166/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/player/AttackBlockCallback.java#L29-L39|AttackBlockCallback]] JavaDoc in your IDE for the meaning of other values.

<yarncode java [enable_line_numbers="true"]>
public class ExampleMod implements ModInitializer {
    [...]
    
    @Override
    public void onInitialize() {
        AttackBlockCallback.EVENT.register((player, world, hand, pos, direction) -> {
            class_2680 state = world.method_8320(pos);
            /* Manual spectator check is necessary because AttackBlockCallbacks
               fire before the spectator check */
            if (state.method_29291() && !player.method_7325() && 
                player.method_6047().method_7960()) {
                player.method_5643(class_1282.field_5869, 1.0F);
            } 
            return class_1269.field_5811;
        });
    }
}
</yarncode>

===== Fabric API Events ======
=== Player Interaction Events ===
Player: [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/player/AttackBlockCallback.java|AttackBlockCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/player/AttackEntityCallback.java|AttackEntityCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/player/UseBlockCallback.java|UseBlockCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/player/UseEntityCallback.java|UseEntityCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/player/UseItemCallback.java|UseItemCallback]]

Player (Client): [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/client/player/ClientPickBlockApplyCallback.java|ClientPickBlockApplyCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/client/player/ClientPickBlockCallback.java|ClientPickBlockCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-interaction-v0/src/main/java/net/fabricmc/fabric/api/event/client/player/ClientPickBlockGatherCallback.java|ClientPickBlockGatherCallback]]

=== Registry Events ===
[[https://github.com/FabricMC/fabric/blob/1.15/fabric-object-builders-v0/src/main/java/net/fabricmc/fabric/api/event/registry/BlockConstructedCallback.java|BlockConstructedCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-object-builders-v0/src/main/java/net/fabricmc/fabric/api/event/registry/ItemConstructedCallback.java|ItemConstructedCallback]]

[[https://github.com/FabricMC/fabric/blob/1.15/fabric-registry-sync-v0/src/main/java/net/fabricmc/fabric/api/event/registry/RegistryEntryAddedCallback.java|RegistryEntryAddedCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-registry-sync-v0/src/main/java/net/fabricmc/fabric/api/event/registry/RegistryEntryRemovedCallback.java|RegistryEntryRemovedCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-registry-sync-v0/src/main/java/net/fabricmc/fabric/api/event/registry/RegistryIdRemapCallback.java|RegistryIdRemapCallback]]

=== Looting Events ===
[[https://github.com/FabricMC/fabric/blob/1.15/fabric-loot-tables-v1/src/main/java/net/fabricmc/fabric/api/loot/v1/event/LootTableLoadingCallback.java|LootTableLoadingCallback]]

There is an example of using ''LootTableLoadingCallback'' [[tutorial:adding_to_loot_tables|here]].

=== World Events ===
[[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-lifecycle-v0/src/main/java/net/fabricmc/fabric/api/event/world/WorldTickCallback.java|WorldTickCallback]]

=== Server Events ===
[[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-lifecycle-v0/src/main/java/net/fabricmc/fabric/api/event/server/ServerStartCallback.java|ServerStartCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-lifecycle-v0/src/main/java/net/fabricmc/fabric/api/event/server/ServerStopCallback.java|ServerStopCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-events-lifecycle-v0/src/main/java/net/fabricmc/fabric/api/event/server/ServerTickCallback.java|ServerTickCallback]]

=== Network Events ===
[[https://github.com/FabricMC/fabric/blob/1.15/fabric-networking-v0/src/main/java/net/fabricmc/fabric/api/event/network/C2SPacketTypeCallback.java|C2SPacketTypeCallback]] / [[https://github.com/FabricMC/fabric/blob/1.15/fabric-networking-v0/src/main/java/net/fabricmc/fabric/api/event/network/S2CPacketTypeCallback.java|S2CPacketTypeCallback]]