---
title: "evaluateURL(_:mainFrameURL:isMainFrame:completionHandler:)"
framework: browserenginekit
role: symbol
role_heading: Instance Method
path: "browserenginekit/bewebcontentfilter/evaluateurl(_:mainframeurl:ismainframe:completionhandler:)"
---

# evaluateURL(_:mainFrameURL:isMainFrame:completionHandler:)

## Declaration

```swift
func evaluateURL(_ url: URL, mainFrameURL: URL, isMainFrame: Bool, completionHandler: @escaping @Sendable (Bool, Data?) -> Void)
```

```swift
func evaluateURL(_ url: URL, mainFrameURL: URL, isMainFrame: Bool) async -> (Bool, Data?)
```

## Parameters

- `url`: The URL to be evaluated, either a main frame or subframe URL.
- `mainFrameURL`: The URL of the main document and root of the transitive trust policy. This may match the evaluated url param for main frame navigations.
- `isMainFrame`: Whether the evaluated URL is a main frame or subframe navigation. YES if main frame navigation and NO otherwise.
- `completionHandler`: The completion block to be invoked when evaluation is complete.

## Discussion

Discussion Evaluates whether a URL should be blocked and if yes, provides a response body representing the HTML of the blocking content that will be displayed in either the blocked main document or blocked subframe.