---
title: completionHandler
framework: uikit
role: symbol
role_heading: Instance Property
path: uikit/uiwritingtoolscoordinator/animationparameters/completionhandler
---

# completionHandler

A custom block to run when the system animations finish.

## Declaration

```swift
var completionHandler: (() -> Void)? { get set }
```

## Discussion

Discussion Set this property to a block that you want the system to run when any animations finish. The block you provide must have no return value and no parameters. The system executes this block once when the current animation finish.

## See Also

### Creating custom animations

- [progressHandler](uikit/uiwritingtoolscoordinator/animationparameters/progresshandler.md)