Fabric Kotlin Boilerplate

Simple Minecraft Fabric mod boilerplate written in Kotlin.

Before you try anything, I recommend you read the sections you're interested in on the Fabric wiki to get acquainted with some of the concepts you'll need to work with.

How to use

This repository is marked as template, so you can just click on Use this template to create a repository based on this one. Rename and edit files to fit your mod.

Add a block

To add a simple block, you only need to add an entry in the block registry helper:

object Blocks {
    val YOURBLOCK = register("your_block_id", Block(FabricBlockSettings.of(Material.LEAVES).hardness(1f)))
    // ...
}

Then add or edit the corresponding resources, changing the values as you need:

src/resources/assets/your_namespace

blockstates/your_block_id.json
```
{
}
```

lang/*.json

{
  "block.your_namespace.your_block_id": "Name to be displayed in language"
}

models/your_model_id.json

{
  "parent": "block/cube_all",
  "textures": {
    "all": "your_namespace:block/your_block_id"
  }
}

textures/your_texture.png

Add a block item

Add complex behaviour

To add complex behaviour to your block, you'll need to define a class in which to define the different components you need. Depending on the kind of behaviour you want to add to the block, you'll need to add different components. To know what to add, I recommend you read the Fabric wiki.

As an example, here's a test block using different states as well as a block entity to implement the following behaviour:

Define (BlockTest):

State COLOUR as an integer property, bound to [0;4].

State COLOURFIXED as a boolean property.

When placed (::Blocktest):

Set state COLOUR to 0.

Set state COLOURFIXED to false.

On tick (BlockTestEntity::tick):

If state COLOURFIXED is false:

Set COLOUR to a random integer value in [0;4].

Else:

Do nothing.

On use (BlockTest::onUse):

If the item the player holds is FLINT_AND_STEEL:

Toggle state COLOURFIXED.

Else:

Do nothing.

Code

class BlockTest(settings: Settings?) : Block(settings), BlockEntityProvider {
    companion object {
        val COLOURFIXED: BooleanProperty = BooleanProperty.of("colour_fixed")
        val COLOUR: IntProperty = IntProperty.of("colour", 0, 4)
    }

    init {
        defaultState = stateManager.defaultState.with(COLOURFIXED, false).with(COLOUR, 0)
    }

    override fun appendProperties(builder: StateManager.Builder<Block, BlockState>?) {
        builder?.add(COLOURFIXED)
        builder?.add(COLOUR)
    }

    override fun createBlockEntity(world: BlockView?): BlockEntity = BlockTestEntity()

    override fun onUse(
        state: BlockState?,
        world: World?,
        pos: BlockPos?,
        player: PlayerEntity?,
        hand: Hand?,
        hit: BlockHitResult?
    ): ActionResult {
        if (!world?.isClient!!) {
            if (player?.getStackInHand(hand)?.item?.name?.string.equals(Items.FLINT_AND_STEEL.name.string)) {
                world.setBlockState(pos, state?.with(COLOURFIXED, !state.get(COLOURFIXED)))
                return ActionResult.SUCCESS
            }
        }
        return ActionResult.PASS
    }
}

class BlockTestEntity : BlockEntity(Blocks.Entities.TEST), Tickable {
    private val rng = Random()
    override fun tick() {
        if (!cachedState.get(BlockTest.COLOURFIXED)) Objects.requireNonNull(getWorld())
            ?.setBlockState(pos, cachedState.with(BlockTest.COLOUR, rng.nextInt(5)))
    }
}

Fuzuki785/fabric-kotlin-boilerplate

Fabric Kotlin Boilerplate

How to use

Add a block

Add a block item

Add complex behaviour

Add an item