state management swiftui

In the WWDC session titled "SwiftUI essentials," state management in SwiftUI is discussed in detail. SwiftUI uses a declarative approach to manage the state of views, which means that views are descriptions of what the current state of the UI should be. This approach eliminates boilerplate code and update bugs by automatically keeping the UI up to date as the view state changes over time.

Key concepts in SwiftUI state management include:

State: This is an internal source of data for a view. When you mark a view property with @State, SwiftUI manages the storage and provides it back for the view to read and write. This is useful for simple state management within a single view.
Binding: A binding creates a two-way reference to the state of another view. This is useful when you want to share state between views, allowing them to stay in sync.
ObservableObject: This is used for more complex state management where multiple views need to observe changes to a shared data model. An ObservableObject can be used to notify views of changes to its properties.

For example, in the session, a view is described that uses state to keep track of a rating value, which can be incremented or decremented. SwiftUI automatically updates the UI when the state changes, and animations can be applied to these updates for a smoother user experience.

For more details, you can refer to the session SwiftUI essentials (08:50) where these concepts are explained.