Datageneration/Loot Tables

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This page is incomplete, and needs more work. Feel free to edit and improve this page!

Loot Tables are not so polished like the other Providers. You need need to do some work to get them to a good state.

Preperation

First you would need a new Class that extend the LootTableProvider. In this class you would override the run and optionally getName Method. In the getName you just return the Name shown in the Logs. Also you should create a abstract Method which you would override in subclasses but this is not strictly needed. Also you need a Gson constant. You would create it like this private static final Gson GSON = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create(); You should also save the DataGenerator for later use since you can't access from the LootTableProvider. Also you would need two Maps, one with the the Class which is used to get the Lootable Resource Location in this example the Block and one the Loot Table Builder. The second Map consist of a ResourceLocation and the actual LootTable. Look at the Code for more info.

private static final Gson GSON = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();

  protected final Map<Block, LootTable.Builder> lootTables = new HashMap<>();
  public static Map<ResourceLocation, LootTable> tables = new HashMap<>();
  protected final DataGenerator generator;

Also you would need a Function to save the Tables

private void writeTables(DirectoryCache cache, Map<ResourceLocation, LootTable> tables) {
    Path outputFolder = this.generator.getOutputFolder();
    tables.forEach((key, lootTable) -> {
      Path path = outputFolder.resolve("data/" + key.getNamespace() + "/loot_tables/" + key.getPath() + ".json");
      try {
        IDataProvider.save(GSON, cache, LootTableManager.serialize(lootTable), path);
      } catch (IOException e) {
        LOGGER.error("Couldn't write loot table {}", path, (Object) e);
      }
    });
  }

For the writeTables method you would need to convert the First Map to the second map, for this we need to iterate over the first map.

lootTables.forEach(blockBuilderMap -> {
      for (Map.Entry<Block, LootTable.Builder> entry : blockBuilderMap.entrySet()) {
        tables.put(entry.getKey().getLootTable(), entry.getValue().build());
      }
    });

in the run method you would then first call the method where you create the tables or just create them in there (if you do you can ignore the next section), then you would convert the Tables and at last you would save the loottables.

The actual Class for Lootables

Another class (Optional)

Create a new class that extends from the Class you created in the Section above and override the abstract function in there you can begin to create your Lootables.

The LootPool Builder

This is where you actually make a loottable. You start with an empty LootPool and add the necessary attributes to it.

• .name is used for the pool name.
• .setRolls is used for the amount.
• .add is used to add an ItemLootEntry. You can have multiple entries.

An ItemLootEntry defines what item is returned, and which functions and/or conditions are applied (see Loot table for the vanilla functions and conditions).

• .lootTableItem is used to define which item is returned.
• .apply is used to apply a function or condition. These themselves can have multiple operations.

After all attributes have been added the LootPool.Builder can be used to make a LootTable.Builder of the proper LootParameterSets. This builder can then be added to an entry in the lootTables map made in the previous section (you should do this in the overwritten abstract method).

LootPool.Builder builder = LootPool.lootPool()
    .name(...)
    .setRolls(...)
    .add(ItemLootEntry.lootTableItem(...)
        .apply(Function1)
        .apply(Function2
            .operation(operation1)
            .operation(operation2))
    );
LootTable.lootTable().withPool(builder).setParamSet(...);