creating.rst

Creating an ItemStack

.. javadoc-import::
    org.spongepowered.api.block.BlockState
    org.spongepowered.api.data.key.Keys
    org.spongepowered.api.data.manipulator.mutable.item.EnchantmentData
    org.spongepowered.api.entity.Entity
    org.spongepowered.api.entity.EntityType
    org.spongepowered.api.entity.EntityTypes
    org.spongepowered.api.entity.Item
    org.spongepowered.api.item.ItemType
    org.spongepowered.api.item.inventory.ItemStack
    org.spongepowered.api.item.inventory.ItemStack.Builder

If you want to create your own items, you need to go through several steps. Let's go through a basic example and create an enchanted diamond sword.

To create an :javadoc:`ItemStack`, we need to first grab the builder from the ItemStack. This is done with the :javadoc:`ItemStack#builder()` method. In the builder, we can specify things such as the :javadoc:`ItemType` or the quantity of the item. In our example, we will be creating a diamond sword that contains enchantments, a custom name, and is unbreakable. If you want a plain sword without any other data, then this is all you need to do:

import org.spongepowered.api.item.ItemTypes;
import org.spongepowered.api.item.inventory.ItemStack;

public ItemStack generateSword() {
    ItemStack superMegaAwesomeSword = ItemStack.builder()
        .itemType(ItemTypes.DIAMOND_SWORD).build();
    return superMegaAwesomeSword;
}

Creating the basic item is done. Now this is a normal diamond sword that we created, but what if we wanted something more interesting? What about enchanting and naming our sword? We can use :javadoc:`EnchantmentData` to give our sword some enchantments. The following example will give our sword every enchantment in the game, to level 1000. Make sure to include this all before return superMegaAwesomeSword;.

import java.util.List;
import java.util.stream.Collectors;

import org.spongepowered.api.Sponge;
import org.spongepowered.api.data.manipulator.mutable.item.EnchantmentData;
import org.spongepowered.api.data.meta.ItemEnchantment
import org.spongepowered.api.item.Enchantment;

EnchantmentData enchantmentData = superMegaAwesomeSword
    .getOrCreate(EnchantmentData.class).get();
final List<EnchantmentType> enchantments = Sponge.getRegistry()
    .getAllOf(EnchantmentType.class).stream().collect(Collectors.toList());

for (EnchantmentType enchantment : enchantments) {
    enchantmentData.set(enchantmentData.enchantments()
        .add(Enchantment.of(enchantment, 1000)));
}
superMegaAwesomeSword.offer(enchantmentData);

Now let's say we wanted to give our overpowered sword a cool name to go with it. Here, we can directly offer a key to the ItemStack. Using this key, we can change the name of the ItemStack to "SUPER MEGA AWESOME Diamond Sword"

import org.spongepowered.api.data.key.Keys;
import org.spongepowered.api.text.Text;
import org.spongepowered.api.text.format.TextColors;

superMegaAwesomeSword.offer(Keys.DISPLAY_NAME, Text.of(
    TextColors.BLUE, "SUPER ",
    TextColors.GOLD, "MEGA ",
    TextColors.DARK_AQUA, "AWESOME ",
    TextColors.AQUA, "Diamond Sword"));

Finally, to make the sword unbreakable, we can use keys again:

superMegaAwesomeSword.offer(Keys.UNBREAKABLE, true);

That's it. You now have a fully enchanted, unbreakable, and beautifully named sword which you can give to players.

Spawning the Item

Sure we can simply put the sword into a player's inventory, but what if we wanted to throw it out into the open world and spawn the item? This is where :doc:`entity spawning <../entities/spawning>` comes into play. Since the in-game graphical representation of an ItemStack is :javadoc:`Item`, we can spawn it in similarly to a normal :javadoc:`Entity`. The :javadoc:`EntityType` will simply be :javadoc:`EntityTypes#ITEM` and we will need to specify that the Entity will represent our ItemStack. This can be done using the :javadoc:`Keys#REPRESENTED_ITEM` key. An example is shown below:

import org.spongepowered.api.entity.Entity;
import org.spongepowered.api.entity.EntityTypes;
import org.spongepowered.api.event.CauseStackManager.StackFrame;
import org.spongepowered.api.world.Location;
import org.spongepowered.api.world.World;
import org.spongepowered.api.world.extent.Extent;

import java.util.Optional;

public void spawnItem(ItemStack superMegaAwesomeSword, Location<World> spawnLocation) {
    Extent extent = spawnLocation.getExtent();
    Entity item = extent.createEntity(EntityTypes.ITEM, spawnLocation.getPosition());
    item.offer(Keys.REPRESENTED_ITEM, superMegaAwesomeSword.createSnapshot());

    try (StackFrame frame = Sponge.getCauseStackManager().pushStackFrame()) {
        frame.addContext(EventContextKeys.SPAWN_TYPE, SpawnTypes.PLACEMENT);
        extent.spawnEntity(item);
    }
}

Creating an ItemStack From a Block

An ItemStack for a block can be created by using the method :javadoc:`ItemStack.Builder#itemType(ItemType)` similarly to normal items, but what if we wanted to create an ItemStack from a :javadoc:`BlockState` itself? To create an ItemStack from a BlockState, you would need to use the :javadoc:`ItemStack.Builder#fromBlockState(BlockState)` method on the ItemStack builder. An example of this is shown below:

import org.spongepowered.api.block.BlockState;

public ItemStack createStack(BlockState state) {
    return ItemStack.builder().fromBlockState(state).build();
}