The AllVariantsLoadedEvent is fired once all known variants for a particular entity have been registered. This allows mod developers to modify, add, or reject variants at the correct time in the loading lifecycle.

There are two phases to this event:

• Pre – allows cancellation or conditional filtering of variants.
• Post – triggered after all variants have been loaded.

Use this to dynamically adjust behavior or content related to entities with multiple variants (e.g., dragon types, mob skins, etc.).

• Can be used to cancel or prevent certain variants from being loaded.
• Only available if the event is cancellable (NeoForge) or returns false (Fabric).

• Used to react to the final set of loaded variants (e.g., logging, applying transformations).

• Remove certain variants based on config or biome rules.
• Inject additional custom variants dynamically.
• Log or validate the final list of variants after load.

@SubscribeEvent
public void onPreVariantsLoad(AllVariantsLoadedEvent.Pre event) {
    if (event.getEntity().equals("example_entity")) {
        event.setCanceled(true); // prevent all variants for this entity from loading
    }
}

@SubscribeEvent
public void onPostVariantsLoad(AllVariantsLoadedEvent.Post event) {
    System.out.println("All variants loaded for: " + event.getEntity());
}

ModLoadingContext.get().getModEventBus().register(new YourModEventHandler());

AllVariantsLoadedEvent.ALLOW_ALL_VARIANTS_TO_LOAD.register(entityName -> {
    if (entityName.equals("example_entity")) {
        return false; // deny loading all variants for this entity
    }
    return true;
});

AllVariantsLoadedEvent.POST.register(entityName -> {
    System.out.println("All variants loaded for: " + entityName);
});

• The entityName string is used to identify which entity's variants are being handled.
• You can use this event to interact with datapack-driven systems, especially if your entities or variants are defined in JSON.