---
title: "compositionParameterView(_:didChangeParameterWithKey:)"
framework: objectivec
role: symbol
role_heading: Instance Method
path: "objectivec/nsobject-swift.class/compositionparameterview(_:didchangeparameterwithkey:)"
---

# compositionParameterView(_:didChangeParameterWithKey:)

Called after an input parameter in the composition parameter view has been edited.

## Declaration

```swift
func compositionParameterView(_ parameterView: QCCompositionParameterView!, didChangeParameterWithKey portKey: String!)
```

## Parameters

- `parameterView`: The composition parameter view in which the parameter changed.
- `portKey`: A key for one of the composition parameters, which is provided to you by the Quartz Composer engine.