---
title: writeCallBack
framework: corefoundation
role: symbol
role_heading: Type Property
path: corefoundation/cfsocketcallbacktype/writecallback
---

# writeCallBack

The callback is called when the socket is writable. This callback type may be useful when large amounts of data are being sent rapidly over the socket and you want a notification when there is space in the kernel buffers for more data.

## Declaration

```swift
static var writeCallBack: CFSocketCallBackType { get }
```

## See Also

### Constants

- [readCallBack](corefoundation/cfsocketcallbacktype/readcallback.md)
- [acceptCallBack](corefoundation/cfsocketcallbacktype/acceptcallback.md)
- [dataCallBack](corefoundation/cfsocketcallbacktype/datacallback.md)
- [connectCallBack](corefoundation/cfsocketcallbacktype/connectcallback.md)