Block Interaction

There are many different ways players (and other things) can interact with blocks, such as right clicking, left clicking, colliding, walking on, and of course mining.

This page will cover the basics of the most common types of interaction with blocks.

Player Right Click

Since left clicking, or "punching", a block does not generally result in any unique behavior, it is probably fair to say right clicking, or "activation", is the most common method of interaction. And thankfully, it is also one of the simplest to handle.

onBlockActivated

public ActionResultType onBlockActivated(BlockState state, World worldIn, BlockPos pos, PlayerEntity player, Hand handIn, BlockRayTraceResult hit)

This is the method that controls right click behavior.

Parameters

Type	Name	Description
BlockState	state	The state of the block that was clicked
World	worldIn	The world that the block was clicked in
BlockPos	pos	The position of the block that was clicked
PlayerEntity	player	The player who did the clicking
Hand	handIn	The hand with which the player clicked
BlockRayTraceResult	hit	Where on the block's bounds it was hit

Return Value

ActionResultType is the result right clicking, see example usages below. ActionResultType.SUCCESS means the right click action was successful. ActionResultType.CONSUME means that the right click action was consumed. ActionResultType.PASS is the default behavior, for when the block has no right click behavior, and allows something else to handle the right click. ActionResultType.FAIL means that the action failed.

Enum Value	Example Usage
SUCCESS	Eating a slice of cake.
CONSUME	Tuning a noteblock.
PASS	When right-clicking dirt. Or any other basic block.
FAIL	When attempting to place a minecart on a block other than rails.

Important

Returning ActionResultType.CONSUME from this method on the client will prevent it being called on the server. It is common practice to just check worldIn.isRemote and return ActionResultType.SUCCESS, and otherwise go on to normal activation logic. Vanilla has many examples of this, such as the chest.

Usage examples

The uses for activation are literally endless. However, there are some common ones which deserve their own section.

GUIs

One of the most common things to do on block activation is opening a GUI. Many blocks in vanilla behave this way, such as chests, hoppers, furnaces, and many more. More about GUIs can be found on [their page](GUIs).

Activation

Another common use for activation is, well, activation. This can be something like "turning on" a block, or triggering it to perform some action. For instance, a block could light up when activated. A vanilla example would be buttons or levers.

Important

onBlockActivated is called on both the client and the server, so be sure to keep the sidedness of your code in mind. Many things, like opening GUIs and modifying the world, should only be done on the server-side.

= Block Placement

onBlockPlacedBy

public void onBlockPlacedBy(World worldIn, BlockPos pos, BlockState state, @Nullable LivingEntity placer, ItemStack stack)

Called by BlockItems after a block is set in the world, to allow post-place logic.

Parameters

Type	Name	Description
World	worldIn	The world that the block was placed in
BlockPos	pos	The position where the block was placed
BlockState	state	The state of the block that was placed
LivingEntity	placer	The entity who placed the block
ItemStack	stack	The item block that was placed

Player Break/Destroy

onBlockClicked

public void onBlockClicked(BlockState state, World worldIn, BlockPos pos, PlayerEntity player)

Called on a block when it is clicked by a player.

Info

This method is for when the player left-clicks on a block.

Don't get this confused with onBlockActivated, which is called when the player right-clicks.

Parameters

Type	Name	Description
BlockState	state	The state of the block that was clicked
World	worldIn	The world that the block was clicked in
BlockPos	pos	The position of the block that was clicked
PlayerEntity	player	The player who did the clicking

Usage example

This method is perfect for adding custom events when a player clicks on a block.

By default this method does nothing. Two blocks that override this method are the NoteBlock and the RedstoneOreBlock.

Note blocks override this method so that when left-clicked, it plays a sound. Redstone ore overrides this method so that when left-clicked, it gives off emits faint light for a few seconds.

onBlockHarvested

public void onBlockHarvested(World worldIn, BlockPos pos, BlockState state, PlayerEntity player)

Called before the Block is set to air in the world. Called regardless of if the player's tool can actually collect this block.

Parameters

Type	Name	Description
World	worldIn	The world that the block was destroyed
BlockPos	pos	The position of the block that was destroyed
BlockState	state	The state of the block that was destroyed
PlayerEntity	player	The player who harvested the block

Usage example

This method is perfect for adding custom events as a result of a player destroying a block

This method has important behavior in the Block class so be sure to call the super method.

super.onBlockHarvested(worldIn, pos, state, player);

The TNTBlock overrides this method to cause it's explosion when a player destroys it. This method is used by extended pistons; since an extended piston is made up of two blocks. (the extended head and the base) The PistonHeadBlock makes use of this method to destroy the base block when the moving head is destroyed.

onEntityCollision

public void onEntityCollision(BlockState state, World worldIn, BlockPos pos, Entity entityIn)

This method is called whenever an entity collides with the block.

Parameters

Type	Name	Description
BlockState	state	The state of the block that was collided with
World	worldIn	The world where the collided block is located
BlockPos	pos	The position of the block that was collided with
Entity	entityIn	The entity who collided with the block

Usage examples

An example use of this method is by the CampfireBlock which uses this method to light those on fire that collide with the campfire.