In this tutorial, you will learn how to generate loot tables for blocks and other contents. With data generation, you do not need to write JSONs for each block anymore. Before reading this, make sure you've read Getting started with Data Generation, and have a class that implements DataGenerationEntrypoint.

To create add a data generation for block loot tables, just create a class which extends FabricBlockLootTableProvider.

TutorialBlockLootTableProvider.java

public class TutorialBlockLootTableProvider extends FabricBlockLootTableProvider {
  protected TutorialBlockLootTableProvider(FabricDataOutput dataOutput, CompletableFuture<RegistryWrapper.WrapperLookup> registryLookup) {
    super(dataOutput, registryLookup);
  }
 
  @Override
  public void generate() {
    // ...
  }
}

And then, add this data generation in the entrypoint (we use ExampleModDataGenerator as an example):

public class ExampleModDataGenerator implements DataGeneratorEntrypoint {
  @Override
  public void onInitializeDataGenerator(FabricDataGenerator generator) {
    FabricDataGenerator.Pack pack = generator.createPack();

    pack.addProvider(TutorialBlockLootTableProvider::new);
  }
}

If you're using versions pre-1.20, please replace pack.addProvider(TutorialBlockLootTableProvider::new); with fabricDataGenerator.addProvider(TutorialBlockLootTableProvider::new); and remove FabricDataGenerator.Pack myPack = fabricDataGenerator.createPack();。

In the previous blocks tutorial, we created an example block. Now let's use the data generator to generate its loot table. It's as simple as:

TutorialBlockLootTableProvider

  @Override
  public void generate() {
    addDrop(TutorialBlocks.EXAMPLE_BLOCK);
  }

This is the most common loot table for a block. When mined, drops one. When exploded in a explosion with decay (such as creeper and nether bed), it may be destroyed totally and drop nothing.

You can also make it drop a little more complex, for example (the code is just to show an exmaple; please do not add loot tables for one block multiple times):

    // drops nothing
    addDrop(TutorialBlocks.EXAMPLE_BLOCK, dropsNothing());
 
    // drops a dirt when mined
    addDrop(TutorialBlocks.EXAMPLE_BLOCK, Blocks.DIRT);
 
    // drops itself only when with tools with Silk Touch, otherwise drops nothing
    addDropWithSilkTouch(TutorialBlocks.EXAMPLE_BLOCK);
 
    // drops itself only when with tools with Silk Touch, otherwise drops a dirt block
    addDropWithSilkTouch(TutorialBlocks.EXAMPLE_BLOCK, Blocks.DIRT);
 
    // drops itself only when with shears or tools with Silk Touch, otherwise drops nothing
    addDrop(TutorialBlocks.EXAMPLE_BLOCK, dropsWithSilkTouchOrShears(TutorialBlocks.EXAMPLE_BLOCK));
 
    // drops three blocks
    addDrop(TutorialBlocks.EXAMPLE_BLOCK, drops(TutorialBlocks.EXAMPLE_BLOCK).apply(SetCountLootFunction.builder(ConstantLootNumberProvider.create(5))));

You can also generate data for the crops we introduced before:

    addDrop(TutorialBlocks.CUSTOM_CROP, cropDrops(TutorialBlocks.CUSTOM_CROP, TutorialItems.CUSTOM_ITEM, TutorialItems.CUSTOM_SEEDS, BlockStatePropertyLootCondition.builder(Blocks.WHEAT).properties(StatePredicate.Builder.create().exactMatch(CropBlock.AGE, 7))));

Firstly, we need an identifier. This identifier points to a json file that contains your chest loot.

// In Tutorial class
public static final Identifier TEST_CHEST = new Identifier("tutorial", "chests/test_loot");

Let's create a chest loot table generator and register it like so.

private static class MyChestLootTables extends SimpleFabricLootTableProvider {
    public MyChestLootGenerator(FabricDataOutput dataGenerator) {
	super(dataGenerator, LootContextTypes.CHEST);
    }
 
    @Override
    public void accept(BiConsumer<Identifier, LootTable.Builder> biConsumer) {
        biConsumer.accept(Tutorial.TEST_CHEST, LootTable.builder()
                  .pool(LootPool.builder().rolls(ConstantLootNumberProvider.create(1.0F))
                  .with(ItemEntry.builder(Items.DIAMOND)
				.apply(SetCountLootFunction.builder(ConstantLootNumberProvider.create(1.0F))))
                  .with(ItemEntry.builder(Items.DIAMOND_SWORD)).apply(EnchantWithLevelsLootFunction.create(UniformLootNumberProvider.create(20.0F, 39.0F))))
        );
    }
}
 
// ...
 
@Override
public void onInitializeDataGenerator(FabricDataGenerator fabricDataGenerator) {
    FabricDataGenerator.Pack myPack = fabricDataGenerator.createPack();
    myPack.addProvider(MyChestLootTables::new);
}

If you're using versions pre-1.20, please replace myPack.addProvider(MyBlockLootTables::new); with fabricDataGenerator.addProvider(MyBlockLootTables::new);。You can also remove FabricDataGenerator.Pack myPack = fabricDataGenerator.createPack();。