---
title: AUImplementorDisplayNameWithLengthCallback
framework: audiotoolbox
role: symbol
role_heading: Type Alias
path: audiotoolbox/auimplementordisplaynamewithlengthcallback
---

# AUImplementorDisplayNameWithLengthCallback

A block called to obtain a parameter node’s display name, possibly truncated to a desired length.

## Declaration

```swift
typealias AUImplementorDisplayNameWithLengthCallback = (AUParameterNode, Int) -> String
```

## Discussion

Discussion This block is only of interest to audio unit subclasses. The block returns a truncated parameter node display name. The block takes the following parameters:

## See Also

### Related Documentation

- [implementorDisplayNameWithLengthCallback](audiotoolbox/auparameternode/implementordisplaynamewithlengthcallback.md)

### Monitoring Parameter Changes

- [AUListenerCreateWithDispatchQueue(_:_:_:_:)](audiotoolbox/aulistenercreatewithdispatchqueue(_:_:_:_:).md)
- [AUListenerCreate(_:_:_:_:_:_:)](audiotoolbox/aulistenercreate(_:_:_:_:_:_:).md)
- [AUParameterListenerNotify(_:_:_:)](audiotoolbox/auparameterlistenernotify(_:_:_:).md)
- [AUParameterFormatValue(_:_:_:_:)](audiotoolbox/auparameterformatvalue(_:_:_:_:).md)
- [AUParameterSet(_:_:_:_:_:)](audiotoolbox/auparameterset(_:_:_:_:_:).md)
- [AUParameterValueFromLinear(_:_:)](audiotoolbox/auparametervaluefromlinear(_:_:).md)
- [AUParameterValueToLinear(_:_:)](audiotoolbox/auparametervaluetolinear(_:_:).md)
- [AUParameterListenerBlock](audiotoolbox/auparameterlistenerblock.md)
- [AUParameterListenerProc](audiotoolbox/auparameterlistenerproc.md)
- [AUParameterListenerRef](audiotoolbox/auparameterlistenerref.md)
- [AUImplementorStringFromValueCallback](audiotoolbox/auimplementorstringfromvaluecallback.md)
- [AUImplementorValueFromStringCallback](audiotoolbox/auimplementorvaluefromstringcallback.md)