tutorial:blockentity_modify_data
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
tutorial:blockentity_modify_data [2024/08/27 02:28] – solidblock | tutorial:blockentity_modify_data [2025/06/11 16:07] (current) – update solidblock | ||
---|---|---|---|
Line 3: | Line 3: | ||
In the previous tutorial, we have created a [[blockentity|block entity]]. But they are too boring as they do not have any data. Therefore, we try to add some data to it, and define ways of serializing and deserializing data. | In the previous tutorial, we have created a [[blockentity|block entity]]. But they are too boring as they do not have any data. Therefore, we try to add some data to it, and define ways of serializing and deserializing data. | ||
+ | ===== Some notes about NbtCompound ===== | ||
+ | |||
+ | Since 1.21.5, methods of '' | ||
+ | |||
+ | <code java> | ||
+ | // no default value specified, returns Optional | ||
+ | Optional< | ||
+ | |||
+ | // default value specified, returns the default value when the field does not exist | ||
+ | int value = nbt.getInt(" | ||
+ | </ | ||
+ | |||
+ | For collection types, such as compounds and lists, an empty object can be returned as a default value, for example: | ||
+ | <code java> | ||
+ | // no default value specified, returns Optional | ||
+ | Optional< | ||
+ | |||
+ | // when the field does not exist, returns an empty compound | ||
+ | NbtCompound config = nbt.getCompoundOrEmpty(" | ||
+ | </ | ||
+ | |||
+ | In versions before 1.21.5, they return zero or empty values. If you need to specify a default value, you need to judge with '' | ||
+ | <code java> | ||
+ | // returns 0 if the field does not exist: | ||
+ | int value = nbt.getInt(" | ||
+ | |||
+ | // returns an empty compound when the field does not exist: | ||
+ | NbtCompound config = nbt.getCompound(" | ||
+ | </ | ||
+ | |||
+ | Besides, since 1.21.5, the whole NBT compound and its fields can be decoded directly with [[codec]]s, such as: | ||
+ | <code java> | ||
+ | NbtCompound nbt = new NbtCompound(); | ||
+ | nbt.put(" | ||
+ | Optional< | ||
+ | </ | ||
+ | |||
+ | <code java> | ||
+ | NbtCompound nbt = new NbtCompound(); | ||
+ | // have to use the RegistryOps since an item is a registry entry | ||
+ | nbt.copyFromCodec(ItemStack.MAP_CODEC, | ||
+ | Optional< | ||
+ | </ | ||
+ | |||
+ | Besides, since 1.21.5, lists support mixing elements of different types. In previous versions, mixing elements of different types in a list results in exceptions. | ||
+ | |||
+ | More information about NBT changes, see [[https:// | ||
===== Serializing Data ===== | ===== Serializing Data ===== | ||
- | If you want to store any data in your '' | + | If you want to store any data in your '' |
- | '' | + | '' |
In older versions, it was very important to call '' | In older versions, it was very important to call '' | ||
Line 13: | Line 60: | ||
Knowing this, the example below demonstrates saving an integer from your '' | Knowing this, the example below demonstrates saving an integer from your '' | ||
+ | //For versions 1.21.5 and before:// | ||
<code java DemoBlockEntity.java> | <code java DemoBlockEntity.java> | ||
public class DemoBlockEntity extends BlockEntity { | public class DemoBlockEntity extends BlockEntity { | ||
Line 25: | Line 73: | ||
// Serialize the BlockEntity | // Serialize the BlockEntity | ||
@Override | @Override | ||
- | public void writeNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup | + | public void writeNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup |
// Save the current value of the number to the nbt | // Save the current value of the number to the nbt | ||
+ | super.writeNbt(nbt, | ||
nbt.putInt(" | nbt.putInt(" | ||
- | |||
- | super.writeNbt(nbt, | ||
} | } | ||
} | } | ||
</ | </ | ||
- | In order to read the data, you will also need to override '' | + | //For versions 1.21.6 and after:// |
+ | <code java> | ||
+ | @Override | ||
+ | public void writeData(WriteView view) { | ||
+ | super.writeData(view); | ||
+ | // Save the current value of the number | ||
+ | view.putInt(" | ||
+ | } | ||
+ | </ | ||
+ | |||
+ | In order to read the data, you will also need to override '' | ||
+ | |||
+ | //For versions 1.21.5 and before:// | ||
<code java> | <code java> | ||
// Deserialize the BlockEntity | // Deserialize the BlockEntity | ||
@Override | @Override | ||
- | public void readNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup | + | public void readNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup |
- | super.readNbt(nbt, | + | super.readNbt(nbt, |
+ | |||
+ | number = nbt.getInt(" | ||
+ | } | ||
+ | </ | ||
+ | |||
+ | //For versions 1.21.6 and after:// | ||
+ | <code java> | ||
+ | @Override | ||
+ | public void readData(ReadView view) { | ||
+ | super.readData(ReadView view); | ||
| | ||
- | number = nbt.getInt(" | + | number = view.getInt(" |
} | } | ||
</ | </ | ||
- | To get the NBT data for the block entity, call '' | + | To get the NBT data for the block entity, call '' |
For old versions, calling '' | For old versions, calling '' | ||
Line 64: | Line 133: | ||
@Override | @Override | ||
- | public NbtCompound toInitialChunkDataNbt(RegistryWrapper.WrapperLookup | + | public NbtCompound toInitialChunkDataNbt(RegistryWrapper.WrapperLookup |
- | return createNbt(registryLookup); | + | return createNbt(registries); |
} | } | ||
</ | </ | ||
Line 78: | Line 147: | ||
} | } | ||
+ | // The following two methods are changed since 1.21.6, see the examples above. | ||
@Override | @Override | ||
- | public void writeNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup | + | public void writeNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup |
+ | super.writeNbt(nbt, | ||
nbt.putInt(" | nbt.putInt(" | ||
- | |||
- | super.writeNbt(nbt, | ||
} | } | ||
| | ||
@Override | @Override | ||
- | public void readNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup | + | public void readNbt(NbtCompound nbt, RegistryWrapper.WrapperLookup |
- | super.readNbt(nbt); | + | super.readNbt(nbt, registries); |
- | number = nbt.getInt(" | + | |
+ | | ||
} | } | ||
} | } | ||
Line 177: | Line 247: | ||
} | } | ||
+ | // For versions 1.21.5 and before: | ||
@Override | @Override | ||
public void removeFromCopiedStackNbt(NbtCompound nbt) { | public void removeFromCopiedStackNbt(NbtCompound nbt) { | ||
nbt.remove(" | nbt.remove(" | ||
+ | } | ||
+ | | ||
+ | // For versions 1.21.6 and after: | ||
+ | @Override | ||
+ | public void removeFromCopiedStackData(WriteView view) { | ||
+ | view.remove(" | ||
} | } | ||
</ | </ | ||
- | The usage of '' | + | The usage of '' |
tutorial/blockentity_modify_data.1724725722.txt.gz · Last modified: 2024/08/27 02:28 by solidblock