Differences

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--- tutorial:events [2020/03/29 15:46] – event -> listener. Highly misleading name, the listener is not an event jamieswhiteshirt
+++ tutorial:events [2025/12/29 07:00] (current) – gauntrecluse
@@ Line 1: / Line 1: @@
-====== Custom Events ======
+~~REDIRECT>https://docs.fabricmc.net/develop/events#custom-events~~
-Fabric API provides an event system that allows mods to react to events in the game. The purpose of adding events is to add hooks that satisfy common use cases and/or providing enhanced compatibility and performance between mods that hook into the same areas of the code. The use of events often substitutes the use of mixins. Fabric API provides events for some use cases, but not all, meaning you'll have to use other methods like Mixins to add a hook. You can then choose to implement the hook as an event.
-In this tutorial, we'll look at creating your own event which is triggered when sheep are sheared. The process of creating an event is:
+====== Custom Events ======
+Fabric API provides a system that allows mods to react to events that occur in the game. Events are hooks that satisfy common use cases and/or provide enhanced compatibility and performance between mods that hook into the same areas of the code. The use of events often substitutes the use of mixins. Fabric API provides events for important areas in the Minecraft codebase that multiple modders may be interested in hooking into. Some areas do not have hooks, so you can opt to use a mixin, or create your own event.
+In this tutorial, we'll look at creating an event that is triggered when sheep are sheared. The process of creating an event is:
   * creating the event callback interface
   * triggering the event from a Mixin
@@ Line 16: / Line 17: @@
 <code java [enable_line_numbers="true"]>
-public interface SheepShearCallback
+public interface SheepShearCallback {
-{
     Event<SheepShearCallback> EVENT = EventFactory.createArrayBacked(SheepShearCallback.class,
         (listeners) -> (player, sheep) -> {
             for (SheepShearCallback listener : listeners) {
                 ActionResult result = listener.interact(player, sheep);
                 if(result != ActionResult.PASS) {
                     return result;
@@ Line 37: / Line 39: @@
 <code java [enable_line_numbers="false"]>
 (listeners) -> (player, sheep) -> {
-    for (SheepShearCallback event : listeners) {
+    for (SheepShearCallback listener : listeners) {
 </code>
 We then call our method (in this case, ''interact'') on the listener to get its response:
 <code java [enable_line_numbers="false"]>
-ActionResult result = event.interact(player, sheep);
+ActionResult result = listener.interact(player, sheep);
 </code>
 If the listener says we have to cancel (''ActionResult.FAIL'') or fully finish (''ActionResult.SUCCESS''), the callback returns the result and finishes the loop. ''ActionResult.PASS'' moves on to the next listener, and in most cases should result in success if there are no more listeners registered:
@@ Line 70: / Line 72: @@
 <code java [enable_line_numbers="false"]>
 @Mixin(SheepEntity.class)
-public class SheepShearMixin
+public class SheepShearMixin {
-{
     @Inject(at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/passive/SheepEntity;dropItems()V"), method = "interactMob", cancellable = true)
     private void onShear(final PlayerEntity player, final Hand hand, final CallbackInfoReturnable<Boolean> info) {
         ActionResult result = SheepShearCallback.EVENT.invoker().interact(player, (SheepEntity) (Object) this);
         if(result == ActionResult.FAIL) {
             info.cancel();
@@ Line 86: / Line 89: @@
 Now we need to test our event. You can register a listener in your initialization method (or other areas if you prefer) and add custom logic there. Here's an example that drops a diamond instead of wool at the sheep's feet:
 <code java [enable_line_numbers="false"]>
-SheepShearCallback.EVENT.register((player, sheep) ->
+SheepShearCallback.EVENT.register((player, sheep) -> {
-{
     sheep.setSheared(true);
@@ Line 101: / Line 103: @@
 If you enter into your game and shear a sheep, a diamond should drop instead of wool.
 {{https://i.imgur.com/dG73Z6G.mp4?400|}}