---
title: Adaptive Trigger API
---

Resource packs should be used for adaptive trigger effects based on item identities, tags, or serialized
data-component values. The Java API is available when an effect needs custom code or cannot be expressed
with resource-pack matching.

Register effects during Controlify pre-initialization:

```java
public final class MyControlifyEntrypoint implements ControlifyEntrypoint {
    @Override
    public void onControlifyPreInit(PreInitContext context) {
        TriggerEffectApi.registerUseItemEffect(
            DataComponents.CHARGED_PROJECTILES,
            projectiles -> new DualsenseTriggerEffect.Feedback(
                (byte) 3,
                (byte) Math.min(8, projectiles.items().size() + 1)
            )
        );
    }
}
```

`TriggerEffectApi` has use-item and swing-item overloads for:

- A `DataComponentType<T>` and a `Function<? super T, DualsenseTriggerEffect>`, for effects computed from
  the component value.
- A `DataComponentType<?>` and a constant `DualsenseTriggerEffect`.
- An `Item` and a constant `DualsenseTriggerEffect`.

Use `registerUseItemEffect` for the input bound to **Use Item** and `registerSwingItemEffect` for the input
bound to **Attack**.

## Priority

[Resource-pack rules](../resource-packs/adaptive-trigger-effects) are always evaluated before Java
registrations, allowing users and pack authors to override mod-provided effects. Among Java registrations,
component functions are checked in registration order before the exact-item fallback. Registering the same
component or item again replaces its previous effect.

Use a resource-pack `off` rule when an effect should be explicitly disabled. An `off` result returned from
Java also disables the trigger, but is only reached when no resource rule matched.