Using capabilities

Fetching capabilities

To fetch an capability, we need to know what capability we are fetching, for the purposes of this example we are gonna be fetching the Fluid Handler capabilities.
In order to do this we can use the CapabilityHelper like so:

ItemHandlerBlockCapability itemHandlerBlock = CapabilityHelper.getCapability(world, x, y, z, ItemHandlerBlockCapability.class);
 
ItemHandlerItemCapability itemHandlerItem = CapabilityHelper.getCapability(itemStack, ItemHandlerItemCapability.class);
 
ItemHandlerEntityCapability itemHandlerEntity = CapabilityHelper.getCapability(entity, ItemHandlerEntityCapability.class);

Some capabilities like ItemHandlerItemCapability can be a bit confusing in their name, however NyaLib always follows the naming convention of <capability_name><target_type>Capability meaning for example the block version of this would be ItemHandlerBlockCapability

Using capabilities

After fetching the capability, we first need to null-check it, if there wasn’t any capability found, the providers will return null. After that we use it by calling methods on the capability class returned.

This is an example piece of code getting an ItemHandler capability of a block and then extracting and item from it and spawning it in world.

ItemHandlerBlockCapability cap = CapabilityHelper.getCapability(world, x, y, z, ItemHandlerBlockCapability.class);  
  
if (cap != null) {  
    ItemStack yoinkedStack = cap.extractItem(Direction.byId(side));  
  
    if (yoinkedStack != null) {  
        ItemEntity itemEntity = new ItemEntity(world, x, y, z, yoinkedStack);  
        world.spawnEntity(itemEntity);  
    }  
}