---
title: "animateAlongsideTransition(in:animation:completion:)"
framework: uikit
role: symbol
role_heading: Instance Method
path: "uikit/uiviewcontrollertransitioncoordinator/animatealongsidetransition(in:animation:completion:)"
---

# animateAlongsideTransition(in:animation:completion:)

Runs the specified animations in a view that’s outside of the designated container view.

## Declaration

```swift
func animateAlongsideTransition(in view: UIView?, animation: ((any UIViewControllerTransitionCoordinatorContext) -> Void)?, completion: ((any UIViewControllerTransitionCoordinatorContext) -> Void)? = nil) -> Bool
```

## Parameters

- `view`: The view (or one of its ancestors) in which the specified animations take place. This parameter must not be nil.
- `animation`: A block containing the animations you want to perform. These animations run in the same context as the transition animations and therefore have the same default attributes. You may specify nil for this parameter. The block has no return value and takes the following parameter:
- `completion`: The block of code to execute after the transition finishes. You may specify nil for this parameter. The block has no return value and takes the following parameter:

## Return Value

Return Value true if the specified animation is successfully queued to run; otherwise false.

## Discussion

Discussion Use this method to perform animations that aren’t handled by the animator objects themselves. The animations you specify in the animation parameter must all take place in a view descended from the view you specify in the view parameter. The animations in the animation parameter are normally performed concurrently with the view controller transition animations. That behavior applies when the animator object’s animateTransition(using:) method is implemented using UIView-based animations. If the animator object uses Core Animation to animate the layer contents directly, your animations are run shortly after the animateTransition: method returns. This method returns false when the block in the animation parameter can’t be queued to run. The completion block can still run even when this method returns false.

## See Also

### Responding to view controller transition progress

- [animate(alongsideTransition:completion:)](uikit/uiviewcontrollertransitioncoordinator/animate(alongsidetransition:completion:).md)
- [notifyWhenInteractionChanges(_:)](uikit/uiviewcontrollertransitioncoordinator/notifywheninteractionchanges(_:).md)
- [notifyWhenInteractionEnds(_:)](uikit/uiviewcontrollertransitioncoordinator/notifywheninteractionends(_:).md)