# init(_:content:animation:) Cycles through a sequence of phases continuously, animating updates to a view on each phase change. ``` nonisolated init(_ phases: some Sequence, @ContentBuilder content: @escaping (Phase) -> Content, animation: @escaping (Phase) -> Animation? = { _ in .default }) ``` ## Parameters `phases` The sequence of phases to cycle through. Ensure that the sequence isn’t empty. If it is, SwiftUI logs a runtime warning and also returns a visual warning as the output view. `content` A content builder closure that takes the current phase as an input. Return a view that’s based on the current phase. `animation` A closure that takes the current phase as input. Return the animation to use when transitioning to the next phase. If you return `nil`, the transition doesn’t animate. If you don’t set this parameter, SwiftUI uses a default animation. ## Discussion When the phase animator first appears, this initializer renders the `content` closure using the first phase as input to the closure. The animator then begins immediately animating to the view produced by sending the second phase to the `content` closure using the animation returned from the `animation` closure. This procedure repeats for successive phases until reaching the last phase, after which the animator loops back to the first phase again. --- Copyright © 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)