Fabric Wiki

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
====== Listening to Events (DRAFT) ======
By the end of this tutorial, you will:
  - Understand Events and Callbacks,
  - Learn how to register a Callback on an existing Event,
  - Make Wool blocks drop Bedrock when broken

===== What's a Callback? =====
Callback functions are pieces of code that you can register to run when certain events happen in Minecraft. (E.g. a block being broken, a  Mods register functions to be called by the They more or less work as less-invasive, less-powerful alternative to Mixin code, and they cover a lot of the cases where you might assume a Mixin is required.

===== Callback Interfaces =====
There is a series of interfaces named [EventName]Callback. They will handle the events (get called by mixins), invoke callbacks which are registered on mod initialization.

==== Callback Interfaces in Fabric API ====
Event Callbacks provided by Fabric API can be found in ''net.fabricmc.fabric.api.event'' package.

Here is a partial list of existing callbacks.

=== Player Interactive 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 using ''LootTableLoadingCallback'' you can find [[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]]

==== 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 ======
<!-- TODO: Add explaination -->

Let's see Take ''AttackBlockCallback'' as an example for how register a listener

Basically, we are going to ... (an event listener) callback to listen the event.

Since there is not more a method that is able to be called on a block clicked, you may want to. If you want to make a ;


As stated in javadoc of ''AttackBlockCallback'', this event accepts ; You can interrupt and stop continuing by sending ActionResult.SUCCESS;

<code java>
/**
 * Callback for left-clicking ("attacking") a block.
 * Is hooked in before the spectator check, so make sure to check for the player's game mode as well!
 *
 * <p>Upon return:
 * <ul><li>SUCCESS cancels further processing and, on the client, sends a packet to the server.
 * <li>PASS falls back to further processing.
 * <li>FAIL cancels further processing and does not send a packet to the server.</ul>
 *
 * <p>ATTACK_BLOCK does not let you control the packet sending process yet.
 */
</code>

<!-- TODO: Really do sth. -->

<code java [enable_line_numbers="true"]>
public class ExampleMod implements ModInitializer
{
    [...]
    
    @Override
    public void onInitialize() {
        AttackBlockCallback.EVENT.register((player, world, hand, pos, direction) -> {
            // Do sth...
            if ([condition]) {
                return ActionResult.SUCCESS;
            } else {
                return ActionResult.PASS;
            }
            
        })
    }
}
</code>

<!-- TODO: An image of the effect of something have done -->