Hey guys

So I have this class, where I get the chance value from a loot_table, it works perfectly, however I would like to add datapack functionality to this. And I'm pretty lost here, I know I have to add datapacks in my getManager(@Nullable World world) method, and I have no idea how to do that atm, so I could use some help achieving this

It is possible that there is a vanilla/forge method where they are already stored, but it's something I haven't been able to find myself

 

The class in question

Spoiler

public class LootTableUtil
{
    public static List<LootPool> getPools(LootTable table)
    {
        // public net.minecraft.loot.LootTable field_186466_c # pools
        return ObfuscationReflectionHelper.getPrivateValue(LootTable.class, table, "field_186466_c");
    }
 
    public static List<ILootCondition> getLootConditions(LootPool pool)
    {
        // public net.minecraft.loot.LootPool field_186454_b # conditions
        return ObfuscationReflectionHelper.getPrivateValue(LootPool.class, pool, "field_186454_b");
    }
 
    public static float getRandomChanceValue(RandomChance condition)
    {
        // public net.minecraft.loot.conditions.RandomChance field_186630_a # chance
        return ObfuscationReflectionHelper.getPrivateValue(RandomChance.class, condition, "field_186630_a");
    }
 
    public static float getRandomChanceWithLootingValue(RandomChanceWithLooting condition)
    {
        // public net.minecraft.loot.conditions.RandomChanceWithLooting field_186627_a # chance
        return ObfuscationReflectionHelper.getPrivateValue(RandomChanceWithLooting.class, condition, "field_186627_a");
    }
 
    public static float getLootingMultiplierValue(RandomChanceWithLooting condition)
    {
        // public net.minecraft.loot.conditions.RandomChanceWithLooting field_186628_b # lootingMultiplier
        return ObfuscationReflectionHelper.getPrivateValue(RandomChanceWithLooting.class, condition, "field_186628_b");
    }
 
    public static float getChance(ResourceLocation resource)
    {
        final Float[] chance = {null};
        final LootTableManager manager = getManager();
 
        LootTable table = manager.getLootTableFromLocation(resource);
 
        getPools(table).forEach(
                pool -> {
                    final List<ILootCondition> poolConditions = getLootConditions(pool);
                    poolConditions.forEach(condition -> {
                            if(condition instanceof RandomChance)
                            {
                                chance[0] = getRandomChanceValue((RandomChance) condition);
                            }
                            else if(condition instanceof RandomChanceWithLooting)
                            {
                                chance[0] = getRandomChanceWithLootingValue((RandomChanceWithLooting) condition);
                            }
                        }
                    );
                }
        );
 
        return chance[0];
    }
 
    public static float getLootingMultiplier(ResourceLocation resource)
    {
        final Float[] lootingMultiplier = {null};
        final LootTableManager manager = getManager();
 
        LootTable table = manager.getLootTableFromLocation(resource);
 
        getPools(table).forEach(
                pool -> {
                    final List<ILootCondition> poolConditions = getLootConditions(pool);
                    poolConditions.forEach(condition -> {
                            if(condition instanceof RandomChanceWithLooting)
                            {
                                lootingMultiplier[0] = getLootingMultiplierValue((RandomChanceWithLooting) condition);
                            }
                        }
                    );
                }
        );
 
        return lootingMultiplier[0];
    }
 
    private static LootTableManager manager;
 
    public static LootTableManager getManager(@Nullable World world)
    {
        if(world == null || world.getServer() == null)
        {
            if(manager == null)
            {
                manager = new LootTableManager(new LootPredicateManager());
 
                SimpleReloadableResourceManager serverResourceManger = new SimpleReloadableResourceManager(ResourcePackType.SERVER_DATA);
                List<IResourcePack> packs = new LinkedList<>();
                packs.add(new VanillaPack("minecraft"));
                for(ModFileInfo mod : ModList.get().getModFiles())
                {
                    if(mod.getFile().getFileName().contains(MagicalJewelry.MOD_ID) || mod.getFile().getFileName().equals("main"))
                    {
                        packs.add(new ModFileResourcePack(mod.getFile()));
                    }
                }
                packs.forEach(serverResourceManger::addResourcePack);
                serverResourceManger.addReloadListener(manager);
                CompletableFuture<Unit> completableFuture = serverResourceManger.reloadResourcesAndThen(Util.getServerExecutor(), Minecraft.getInstance(), packs, CompletableFuture.completedFuture(Unit.INSTANCE));
                Minecraft.getInstance().driveUntil(completableFuture::isDone);
            }
            return manager;
        }
        return world.getServer().getLootTableManager();
    }
 
    public static LootTableManager getManager()
    {
        World world = Minecraft.getInstance().world;
        return getManager(world);
    }
}

 

 

12 hours ago, diesieben07 said:

• You should use ObfuscationReflectionHelper.getField and store that in a static final field. getPrivateValue is slow and therefore should be used only for one-off lookups.
• Your code in getManager(World) makes zero sense. Do not try to make your own LootTableManager... Why are you doing that? MinecraftServer#getLootTables gives it to you.
• Your code in getManager() makes no sense either. This will hard-crash on servers (the server has no Minecraft class) and in generate data pack things are server side, so using Minecraft#world for it doesn't work.

I don't see those two methods, getField and getLootTables, I assume it's findField and getLootTableManager?

 

It's my first time doing anything with reflection, so will that method still get the value?

8 minutes ago, Erfurt said:

I don't see those two methods, getField and getLootTables, I assume it's findField and getLootTableManager?

yes

9 minutes ago, Erfurt said:

It's my first time doing anything with reflection, so will that method still get the value?

if you store the value in a static final field?
yes this is basic java

So, I have done some work on this, and I think I just need to get the LootTableManager now. But since Minecraft#world is wrong, I don't know how to get it then.

8 hours ago, diesieben07 said:

MinecraftServer#getLootTableManager, just call it.

I would love to, but non-static, my methods are used within some commands that are static

1 hour ago, diesieben07 said:

Commands get the CommandSource passed in, which has a getServer method.

Ah yes, off course... I'm stupid...