This just won't work no matter how I do it.

I have been wasting several days of my life trying to get this dumb code to work, but it just won't work the way I want it to no matter how I do it.

I am trying to make a system where the player gets certain attribute modifiers based off a data-driven system if they have certain items equipped.

Here's the class: (No this has nothing to do with the vanilla statistics system you can view in the pause menu.)

package everyblu.greateradv.common.events;

import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Multimap;
import everyblu.greateradv.GreaterAdventuresMod;
import everyblu.greateradv.common.entities.mobs.NetherPaladin;
import everyblu.greateradv.common.init.InitEntityTypes;
import everyblu.greateradv.common.systems.statistics.Statistics;
import everyblu.greateradv.common.systems.statistics.StatisticsManager;
import everyblu.greateradv.common.utils.StatisticsAttributeUtils;
import net.minecraft.world.entity.ai.attributes.Attribute;
import net.minecraft.world.entity.ai.attributes.AttributeModifier;
import net.minecraft.world.entity.ai.attributes.Attributes;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.ItemStack;
import net.minecraftforge.event.TickEvent;
import net.minecraftforge.event.entity.EntityAttributeCreationEvent;
import net.minecraftforge.event.entity.player.PlayerEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.fml.common.Mod;

public class CommonEvents {
    @Mod.EventBusSubscriber(modid = GreaterAdventuresMod.MOD_ID, bus = Mod.EventBusSubscriber.Bus.FORGE)
    public static class ForgeEvents {
        @SubscribeEvent
        public static void playerPopulateStatisticsAttributes(PlayerEvent.PlayerRespawnEvent event) {
            if (event.isEndConquered()) {return;} // Pretty sure the player keeps their stuff after conquering the end, so skip this event if that happens.

            event.getEntity().getAttribute(Attributes.MAX_HEALTH).addTransientModifier(StatisticsAttributeUtils.getStatisticsModifierForAttribute(Attributes.MAX_HEALTH, 0));
        }

        @SubscribeEvent
        public static void itemStatisticsEquipmentHandler(TickEvent.PlayerTickEvent event) {
            Player player = event.player;

            if (event.phase == TickEvent.Phase.START) {
                float totalMaxHealthBonus = 0;
                float totalKnockbackResistanceBonus = 0;
                float totalArmorBonus = 0;
                float totalArmorToughnessBonus = 0;
                float totalAttackDamageBonus = 0;

                for (ItemStack stack : player.getAllSlots()) {
                    if (stack.isEmpty()) {continue;}
                    Statistics itemStatistics = StatisticsManager.Registry.getItemStatsManagerInstance().getStatisticsForItem(stack.getItem());
                    if (itemStatistics == null) {continue;}

                    if (itemStatistics.maxHealthStat() != null) {totalMaxHealthBonus += itemStatistics.maxHealthStat().getValue();}
                    if (itemStatistics.knockbackResistanceStat() != null) {totalKnockbackResistanceBonus += itemStatistics.knockbackResistanceStat().getValue();}
                    if (itemStatistics.armorStat() != null) {totalArmorBonus += itemStatistics.armorStat().getValue();}
                    if (itemStatistics.armorToughnessStat() != null) {totalArmorToughnessBonus += itemStatistics.armorToughnessStat().getValue();}
                    if (itemStatistics.attackDamageStat() != null) {totalAttackDamageBonus += itemStatistics.attackDamageStat().getValue();}
                }

                Multimap<Attribute,AttributeModifier> oldModifiers = ArrayListMultimap.create();
                oldModifiers.put(Attributes.MAX_HEALTH, player.getAttribute(Attributes.MAX_HEALTH).getModifier(StatisticsAttributeUtils.MAX_HEALTH_UUID));

                Multimap<Attribute, AttributeModifier> newModifiers = ArrayListMultimap.create();
                newModifiers.put(Attributes.MAX_HEALTH, StatisticsAttributeUtils.getStatisticsModifierForAttribute(Attributes.MAX_HEALTH, totalMaxHealthBonus));

                player.getAttributes().removeAttributeModifiers(newModifiers);
                player.getAttributes().addTransientAttributeModifiers(newModifiers);
            }
        }
    }

    @Mod.EventBusSubscriber(modid = GreaterAdventuresMod.MOD_ID, bus = Mod.EventBusSubscriber.Bus.MOD)
    public static class ModEvents {
        @SubscribeEvent
        public static void initEntityAttributes(EntityAttributeCreationEvent event) {
            event.put(InitEntityTypes.NETHER_PALADIN.get(), NetherPaladin.createAttributes().build());
        }
    }
}

StatisticsAttributeUtils:

package everyblu.greateradv.common.utils;

import net.minecraft.world.entity.ai.attributes.Attribute;
import net.minecraft.world.entity.ai.attributes.AttributeModifier;
import net.minecraft.world.entity.ai.attributes.Attributes;

import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

public class StatisticsAttributeUtils {
    public static final UUID MAX_HEALTH_UUID = UUID.fromString("e67a8b8e-5e17-439b-84fc-89b33aaabfbf");
    public static final UUID KNOCKBACK_RESISTANCE_UUID = UUID.fromString("c53f398b-1e6f-47e2-9a37-7b85edc02161");
    public static final UUID ARMOR_UUID = UUID.fromString("9ef4377c-48b2-43df-ab1d-276abbc2331a");
    public static final UUID ARMOR_TOUGHNESS_UUID = UUID.fromString("96f6e24e-227e-48f2-aafc-8e60554d9d97");
    public static final UUID ATTACK_DAMAGE_UUID = UUID.fromString("02075396-74b1-486d-99be-4dfe5d20d6d9");

    private static final Map<Attribute, UUID> ATTRIBUTE_TO_UUID = new HashMap<>();
    static {
        ATTRIBUTE_TO_UUID.put(Attributes.MAX_HEALTH, MAX_HEALTH_UUID);
        ATTRIBUTE_TO_UUID.put(Attributes.KNOCKBACK_RESISTANCE, KNOCKBACK_RESISTANCE_UUID);
        ATTRIBUTE_TO_UUID.put(Attributes.ARMOR, ARMOR_UUID);
        ATTRIBUTE_TO_UUID.put(Attributes.ARMOR_TOUGHNESS, ARMOR_TOUGHNESS_UUID);
        ATTRIBUTE_TO_UUID.put(Attributes.ATTACK_DAMAGE, ATTACK_DAMAGE_UUID);
    }

    public static AttributeModifier getStatisticsModifierForAttribute(Attribute attribute, float amount) {
        UUID uuid = ATTRIBUTE_TO_UUID.get(attribute);

        return new AttributeModifier(uuid, "itemStatistics " + attribute + "Modifier", amount, AttributeModifier.Operation.ADDITION);
    }
}

Let me know if you need to see more code. Any help is highly appreciated.

Edited April 8, 20241 yr by EveryBlu