---
title: "fetchDataRecords(ofTypes:completionHandler:)"
framework: webkit
role: symbol
role_heading: Instance Method
path: "webkit/wkwebextensioncontroller/fetchdatarecords(oftypes:completionhandler:)"
---

# fetchDataRecords(ofTypes:completionHandler:)

Fetches data records containing the given extension data types for all known extensions.

## Declaration

```swift
func fetchDataRecords(ofTypes dataTypes: Set<WKWebExtension.DataType>, completionHandler: @escaping ([WKWebExtension.DataRecord]) -> Void)
```

```swift
func dataRecords(ofTypes dataTypes: Set<WKWebExtension.DataType>) async -> [WKWebExtension.DataRecord]
```

## Parameters

- `dataTypes`: The extension data types to fetch records for.
- `completionHandler`: A block to invoke when the data records have been fetched.

## Discussion

Discussion note: The extension does not need to be loaded to be included in the result.