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# kAudioUnitProperty_ClassInfoFromDocument

A read/write CFDictionary object, valid on the audio unit global scope.

```
var kAudioUnitProperty_ClassInfoFromDocument: AudioUnitPropertyID { get }
```

## Discussion

If the audio unit implements this property then it is going to do different actions establishing its state from a document rather than from a user preset. Thus, a host app should use this property first (instead of kAudioUnitProperty_ClassInfo) when restoring the state of an audio unit when opening a document. If the audio unit returns an error (or doesn’t implement this property) then the host should use the same preset with the kAudioUnitProperty_ClassInfo.

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