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Modifying Blocks

.. javadoc-import::
    org.spongepowered.api.block.BlockSnapshot
    org.spongepowered.api.block.BlockState
    org.spongepowered.api.block.BlockType
    org.spongepowered.api.data.ImmutableDataHolder
    org.spongepowered.api.data.manipulator.ImmutableDataManipulator
    org.spongepowered.api.data.manipulator.mutable.WetData
    org.spongepowered.api.data.manipulator.mutable.block.DirtData
    org.spongepowered.api.data.type.DirtTypes
    org.spongepowered.api.event.cause.Cause
    org.spongepowered.api.world.Location

Changing a Blocks Type

Changing the Type of a Block is as simple as calling the :javadoc:`Location#setBlockType(BlockType, Cause)` method with the new :javadoc:`BlockType`. As with most block modifications, we need to supply a cause for the block change. In most cases, this can be your main plugin class. The following code turns the block at the given :javadoc:`Location` into a sponge:

import org.spongepowered.api.block.BlockTypes;
import org.spongepowered.api.event.cause.Cause;
import org.spongepowered.api.world.Location;
import org.spongepowered.api.world.World;

public void setToSponge(Location<World> blockLoc, Object myPluginInstance) {
    blockLoc.setBlockType(BlockTypes.SPONGE, Cause.source(myPluginInstance).build());
}

It's as simple as that. If you just want to 'delete' a block (which is done by replacing it with air), you may just use the :javadoc:`Location#removeBlock(Cause)` method provided by Location.

Altering Block States

Similar to the above example, the Location class provides a :javadoc:`Location#setBlock(BlockState, Cause)` method accepting a new :javadoc:`BlockState`. To make use of it, you first must acquire a BlockState you can modify. You can do so either by getting the block's current state via the :javadoc:`Location#getBlock()` method or by using a BlockType's default state. The latter is demonstrated below. The default state for a Sponge block is retrieved and then modified to directly create a wet sponge block:

import org.spongepowered.api.Sponge;
import org.spongepowered.api.block.BlockState;
import org.spongepowered.api.data.manipulator.mutable.WetData;

public void setToWetSponge(Location<World> blockLoc, Object myPluginInstance) {
    BlockState state = BlockTypes.SPONGE.getDefaultState();
    WetData wetness = Sponge.getDataManager().
        getManipulatorBuilder(WetData.class).get().create();
    wetness.set(wetness.wet().set(true));
    BlockState newState = state.with(wetness.asImmutable()).get();
    blockLoc.setBlock(newState, Cause.source(myPluginInstance).build());
}

Since a BlockState is an :javadoc:`ImmutableDataHolder`, you may use the provided methods with() and without(), both of which will return a new altered BlockState or Optional.empty() if the given :javadoc:`ImmutableDataManipulator` is not applicable to the kind of block represented by the BlockState.

The with() method accepts an ImmutableDataManipulator and will try to create a new BlockState with the given data set, overwriting existing values. The following example will change any dirt block to podzol.

import org.spongepowered.api.data.key.Keys;
import
    org.spongepowered.api.data.manipulator.immutable.block.ImmutableDirtData;
import org.spongepowered.api.data.manipulator.mutable.block.DirtData;
import org.spongepowered.api.data.type.DirtTypes;

public void dirtToPodzol(Location<World> blockLoc, Object myPluginInstance) {
    BlockState state = blockLoc.getBlock();
    Optional<ImmutableDirtData> dirtDataOpt =
        state.get(ImmutableDirtData.class);

    if (dirtDataOpt.isPresent()) {
        DirtData dirtData = dirtDataOpt.get().asMutable();
        dirtData.set(Keys.DIRT_TYPE, DirtTypes.PODZOL);
        BlockState dirtState = state.with(dirtData.asImmutable()).get();
        blockLoc.setBlock(dirtState, Cause.source(myPluginInstance).build());
    }
}

Note that the :javadoc:`DirtData` is a mutable copy of the data held in the BlockState. It is changed and then converted back to an immutable and used to create a new BlockState which then replaces the original block.

The without() method accepts a class reference and will create a new BlockState without the data represented by the given class. If the block state would not be valid without that data, a default value will be used. So if the DirtData from a dirt blocks state is removed, it will fall back to :javadoc:`DirtTypes#DIRT`, the default value. The following example will dry the block at a given Location, if possible.

import
    org.spongepowered.api.data.manipulator.immutable.block.ImmutableWetData;

public void dry(Location<World> blockLoc, Object myPluginInstance) {
    BlockState wetState = blockLoc.getBlock();
    Optional<BlockState> dryState = wetState.without(ImmutableWetData.class);
    if (dryState.isPresent()) {
        blockLoc.setBlock(dryState.get(), Cause.source(myPluginInstance).build());
    }
}

Since the :javadoc:`WetData` data manipulator represents boolean data, by removing it we set the wetness of the block (if it has any) to false. The dryState.isPresent() check will fail on block states that can not be wet since dryState will be Optional.empty() in that case.

Copying Blocks

If you want to copy all of a block's data, the :javadoc:`BlockSnapshot` class is your best friend. While it doesn't expose all the data, it stores a BlockType, its BlockState and, if necessary, all additional Tile Entity Data (for example chest inventories). Conveniently, the Location class provides a :javadoc:`Location#createSnapshot()` method to create a snapshot of the block at that point in time. That makes copying blocks from one location to another very simple:

import org.spongepowered.api.block.BlockSnapshot;

public void copyBlock(Location<World> from, Location<World> to, Object myPluginInstance) {
    BlockSnapshot snapshot = from.createSnapshot();
    to.setBlock(snapshot.getState(), Cause.source(myPluginInstance).build());
}