ExampleComponents.java

package com.example.examplemod;

import com.mojang.serialization.Codec;
import com.mojang.serialization.codecs.RecordCodecBuilder;
import net.minecraft.component.ComponentType;
import net.minecraft.component.type.NbtComponent;
import net.minecraft.item.ItemStack;
import net.minecraft.network.codec.PacketCodecs;
import net.minecraft.registry.Registries;
import net.minecraft.registry.Registry;
import net.minecraft.text.Text;
import net.minecraft.util.Identifier;

/**
 * The 1.20.5+ DataComponent system replaced NBT-based item data and is the
 * standard way to attach custom data to ItemStacks in 1.21.7 - 1.21.11.
 *
 * Example: a "Charge Level" component for a custom tool that tracks
 * remaining charges and shows it in the tooltip.
 */
public final class ExampleComponents {

    private ExampleComponents() {}

    // A simple integer component: how many "charges" remain on the item.
    public static final ComponentType<Integer> CHARGE_LEVEL = Registry.register(
            Registries.DATA_COMPONENT_TYPE,
            Identifier.of(ExampleMod.MOD_ID, "charge_level"),
            ComponentType.<Integer>builder()
                    .codec(Codec.INT)
                    .packetCodec(PacketCodecs.VAR_INT)
                    .build()
    );

    /** Set initial charge on item creation. */
    public static ItemStack withCharges(ItemStack stack, int charges) {
        stack.set(CHARGE_LEVEL, charges);
        return stack;
    }

    /** Consume one charge; returns true if there was a charge to consume. */
    public static boolean consumeCharge(ItemStack stack) {
        Integer current = stack.get(CHARGE_LEVEL);
        if (current == null || current <= 0) return false;
        stack.set(CHARGE_LEVEL, current - 1);
        return true;
    }

    /** Build a tooltip line showing remaining charges (call from an Item subclass override). */
    public static Text getChargeTooltip(ItemStack stack) {
        Integer current = stack.getOrDefault(CHARGE_LEVEL, 0);
        return Text.literal("Charges: " + current).formatted(net.minecraft.util.Formatting.AQUA);
    }
}