---
title: predicate
framework: homekit
role: symbol
role_heading: Instance Property
path: homekit/hmeventtrigger/predicate
---

# predicate

The predicate to evaluate before executing the scene associated with the event trigger.

## Declaration

```swift
@NSCopying var predicate: NSPredicate? { get }
```

## Discussion

Discussion By default, the value of this property is nil, which means that it evaluates as true.

## See Also

### Adding a trigger condition

- [updatePredicate(_:completionHandler:)](homekit/hmeventtrigger/updatepredicate(_:completionhandler:).md)