<!--
{
  "availability" : [
    "macOS: -"
  ],
  "documentType" : "symbol",
  "framework" : "AddressBook",
  "identifier" : "/documentation/AddressBook/ABImageClientCallback",
  "metadataVersion" : "0.1.0",
  "role" : "Type Alias",
  "symbol" : {
    "kind" : "Type Alias",
    "modules" : [
      "Address Book"
    ],
    "preciseIdentifier" : "c:@T@ABImageClientCallback"
  },
  "title" : "ABImageClientCallback"
}
-->

# ABImageClientCallback

Prototype of a callback function used to notify an application when an asynchronous image fetch is complete.

```
typealias ABImageClientCallback = (CFData?, CFIndex, UnsafeMutableRawPointer?) -> Void
```

## Parameters

`imageData`

The image data in Quicktime compatible format that was loaded from an asynchronous fetch. `NULL` if the fetch failed.

`tag`

The tracking number for this fetch that should have been obtained from a previous call to the [`ABBeginLoadingImageDataForClient(_:_:_:)`](/documentation/AddressBook/ABBeginLoadingImageDataForClient(_:_:_:)) function.

`info`

An untyped pointer to program-defined data that was passed to the [`ABBeginLoadingImageDataForClient(_:_:_:)`](/documentation/AddressBook/ABBeginLoadingImageDataForClient(_:_:_:)) function.

## Discussion

Use the [`ABBeginLoadingImageDataForClient(_:_:_:)`](/documentation/AddressBook/ABBeginLoadingImageDataForClient(_:_:_:)) function to begin an asynchronous fetch, and the [`ABCancelLoadingImageDataForTag(_:)`](/documentation/AddressBook/ABCancelLoadingImageDataForTag(_:)) function to cancel an asynchronous fetch.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)