https://github.com/timdonnelly/SwiftUITimeTravel

An experimental time traveling state store for SwiftUI
https://github.com/timdonnelly/SwiftUITimeTravel

Last synced: 2 months ago
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An experimental time traveling state store for SwiftUI

• Host: GitHub
• URL: https://github.com/timdonnelly/SwiftUITimeTravel
• Owner: timdonnelly
• License: mit
• Created: 2019-06-05T08:24:40.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2019-10-31T04:54:13.000Z (about 5 years ago)
• Last Synced: 2024-10-28T11:45:21.823Z (3 months ago)
• Language: Swift
• Homepage:
• Size: 777 KB
• Stars: 141
• Watchers: 2
• Forks: 4
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-swiftui - timdonnelly/SwiftUITimeTravel - An experimental time traveling state store for SwiftUI (Samples)
• fucking-about-SwiftUI - SwiftUITimeTravel

README

        
# SwiftUI Time Travel

A SwiftUI state store and view that allow you to scrub through an application's state.

This is a super rough prototype: it's only meant to serve as an example of what can be done using SwiftUI.

![animated gif](image.gif)

-----

### How this works

Any view hierarchy can use time travel: in the provided todo app, `ContentView` adds time travel like this:

```swift

struct ContentView : View {

    var body: some View {

        TimeTravelView(initialState: TodoState()) {

            TodoListView()

        }

    }

}

```

Then you can use `@EnvironmentObject` to access the state store from views within the hierarchy.

```swift

struct MyView: View {

    @EnvironmentObject var store: Store

    var body: some View {

        Text("Count: \(store.state.todoItems.count)")

    }

}

```

To update your application's state, use the `dispatch` method on the store:

```swift

struct MyView: View {

    @EnvironmentObject var store: Store

    var body: some View {

        VStack(spacing: 10) {

            Text("Count: \(store.state.todoItems.count)")

            HStack(spacing: 10) {

                Button(action: { self.store.dispatch(event: .someEventName) }) {

                    Text("Do Something")

                }

            }

        }

    }

}

```

For time travel to work, all state must be accessed like this. Any state that is stored outside of the single `Store` will not be controlled by the time travel view. This means that local view state (using `@State`) should be used sparingly (if at all).

Internally, the store keeps a stack of all states that have occured – the slider controls which of those states is used as the active (current) state.