<!--
{
  "availability" : [
    "DriverKit: 27.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "VideoDriverKit",
  "identifier" : "/documentation/VideoDriverKit/IOUserVideoCustomProperty/HandleChangeCustomPropertyDataValueWithQualifier",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "VideoDriverKit"
    ],
    "preciseIdentifier" : "c:@S@IOUserVideoCustomProperty@F@HandleChangeCustomPropertyDataValueWithQualifier#*$@S@OSObject#S0_#"
  },
  "title" : "HandleChangeCustomPropertyDataValueWithQualifier"
}
-->

# HandleChangeCustomPropertyDataValueWithQualifier

The system calls this virtual method when the custom property’s data value changes.

```
virtual kern_return_t HandleChangeCustomPropertyDataValueWithQualifier(OSObject *in_qualifier_data, OSObject *in_data);
```

## Parameters

`in_qualifier_data`

The qualifier data OSObject associated with setting the property data value.
Can be a nullptr, OSString, or OSDictionary.

`in_data`

The data OSObject that is getting set for the custom property.
Can be a OSString or OSDictionary.

## Return Value

`kIOReturnSuccess` on success. Upon success the custom property’s data value should be updated.

## Discussion

The default implementation always returns `kIOReturnSuccess` and updates the custom
property data value without checking qualifier contents.
Subclass and override this method to handle changes to this custom property value and
return `kIOReturnSuccess` upon success.

---

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)