---
title: dataAvailable
framework: foundation
role: symbol
role_heading: Type Property
path: foundation/notificationcenter/messageidentifier/dataavailable
---

# dataAvailable

An identifier for a message about a file handle having data available for reading.

## Declaration

```swift
static var dataAvailable: NotificationCenter.BaseMessageIdentifier<FileHandle.DataAvailableMessage> { get }
```

## Discussion

Discussion Use this identifier with NotificationCenter’s addObserver(of:for:using:) or messages(of:for:bufferSize:) methods to observe messages of type FileHandle.DataAvailableMessage.

## See Also

### Identifying file handle messages

- [connectionAccepted](foundation/notificationcenter/messageidentifier/connectionaccepted.md)
- [readToEndOfFileCompletion](foundation/notificationcenter/messageidentifier/readtoendoffilecompletion.md)
- [readCompletion](foundation/notificationcenter/messageidentifier/readcompletion.md)