<!--
{
  "availability" : [
    "iOS: 5.0.0 -",
    "iPadOS: 5.0.0 -",
    "macCatalyst: 13.1.0 -",
    "visionOS: 1.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "MessageUI",
  "identifier" : "/documentation/MessageUI/MFMessageComposeViewControllerTextMessageAvailabilityDidChangeNotification",
  "metadataVersion" : "0.1.0",
  "role" : "Global Variable",
  "symbol" : {
    "kind" : "Global Variable",
    "modules" : [
      "Message UI"
    ],
    "preciseIdentifier" : "c:@MFMessageComposeViewControllerTextMessageAvailabilityDidChangeNotification"
  },
  "title" : "MFMessageComposeViewControllerTextMessageAvailabilityDidChangeNotification"
}
-->

# MFMessageComposeViewControllerTextMessageAvailabilityDidChangeNotification

Posted when the value returned by the [`canSendText()`](/documentation/MessageUI/MFMessageComposeViewController/canSendText()) class method has changed.

```
extern NSString * const MFMessageComposeViewControllerTextMessageAvailabilityDidChangeNotification;
```

## Discussion

Upon receiving this notification, query its `userInfo` dictionary with the [`MFMessageComposeViewControllerTextMessageAvailabilityKey`](/documentation/MessageUI/MFMessageComposeViewControllerTextMessageAvailabilityKey) key. If the availability of text message sending has changed, your app should invalidate caches and update its user interface as appropriate.

---

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