---
title: MFMessageComposeViewControllerTextMessageAvailabilityDidChange
framework: foundation
role: symbol
role_heading: Type Property
path: foundation/nsnotification/name-swift.struct/mfmessagecomposeviewcontrollertextmessageavailabilitydidchange
---

# MFMessageComposeViewControllerTextMessageAvailabilityDidChange

Posted when the current device’s ability to send text messages changes.

## Declaration

```swift
static let MFMessageComposeViewControllerTextMessageAvailabilityDidChange: NSNotification.Name
```

## Discussion

Discussion The system posts this notification when the value canSendText() returns has changed. Upon receiving this notification, query its userInfo dictionary with the MFMessageComposeViewControllerTextMessageAvailabilityKey key. If the availability of text message sending has changed, your app should invalidate caches and update its user interface as appropriate.