---
title: progressHandler
framework: uikit
role: symbol
role_heading: Instance Property
path: uikit/uiwritingtoolscoordinator/animationparameters/progresshandler
---

# progressHandler

A custom block that runs at the same time as the system animations.

## Declaration

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

## Discussion

Discussion If you have animations you want to run at the same time as the system animations, assign a block to this property and use it to run your animations. The block you provide must have no return value and take a floating-point value as a parameter. The parameter indicates the current progress of the animations as a percentage value between 0.0 to 1.0. The system executes your block multiple times during the course of the animations, providing an updated completion value each time.

## See Also

### Creating custom animations

- [completionHandler](uikit/uiwritingtoolscoordinator/animationparameters/completionhandler.md)