---
title: "gestureRecognizer(_:shouldBeRequiredToFailBy:)"
framework: uikit
role: symbol
role_heading: Instance Method
path: "uikit/uigesturerecognizerdelegate/gesturerecognizer(_:shouldberequiredtofailby:)"
---

# gestureRecognizer(_:shouldBeRequiredToFailBy:)

Asks the delegate if a gesture recognizer should be required to fail by another gesture recognizer.

## Declaration

```swift
optional func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool
```

## Parameters

- `gestureRecognizer`: An instance of a subclass of the abstract base class doc://com.apple.uikit/documentation/UIKit/UIGestureRecognizer. This is the object sending the message to the delegate.
- `otherGestureRecognizer`: An instance of a subclass of the abstract base class doc://com.apple.uikit/documentation/UIKit/UIGestureRecognizer.

## Mentioned in

Preferring one gesture over another

## Return Value

Return Value true to set up a dynamic failure requirement between gestureRecognizer and otherGestureRecognizer. The default implementation returns false—gestureRecognizer isn’t required to fail by otherGestureRecognizer.

## Discussion

Discussion This method is called once per attempt to recognize, so failure requirements can be determined lazily and may be set up between recognizers across view hierarchies. Note that returning true is guaranteed to set up the failure requirement; returning false, on the other hand, isn’t guaranteed to prevent or remove a failure requirement because otherGestureRecognizer might make itself a failure requirement by using its own subclass or delegate methods.

## See Also

### Setting up failure requirements

- [gestureRecognizer(_:shouldRequireFailureOf:)](uikit/uigesturerecognizerdelegate/gesturerecognizer(_:shouldrequirefailureof:).md)