Prestige is a predictable state container, written in Swift. Inspired by Redux and Vuex, it aims to enforce separation of concerns and a unidirectional data flow by keeping your entire app state in a single data structure that shouldn't be mutated directly, instead relying on an action dispatch mechanism to describe changes. Prestige uses PromiseKit for whenever a dispatch is done.
Define your app state. In this example I am using a struct. the state of your application is stored in a single data structure. This makes it easier to understand the behavior of the app state at any given point in time, simplifies state persistence and improves code readability:
struct AppState: State {
var counter: Int = 0
}As an example, operations that users might perform within your app would be described as actions. State should only be mutated through dispatched actions, lightweight objects that mutate the state. Since mutations are centralized, inconsistencies are infrequent and race-conditions become easier to avoid:
struct IncrementAction {
let increment: Int
}
extension IncrementAction: Action {
func aysnc(_ store: Store<AppState>) -> Promise<Void> {
return after(seconds: 1) {
store.commit(\.count, store.counter + self.increment)
}.asVoid()
}
}Then you would define a store, a data structure used to hold and safeguard your state. A typical application would define only one store and hold it in memory for its lifetime:
The store can initialize the AppState itself if default values are set.
let store = Store<AppState>() otherwise you can initalize the AppState yourself by overriding the store initializer
let store = Store<AppState>(state: AppState(counter: 0)) Actions are dispatched through the store, and promise is returned when an action is completed or has an error:
store.dispatch(IncrementAction(increment: 3))
.done {
print(store.counter) // 3
}
.catch { error in
print(error)
}You can change a value in the state using the store's commit method
store.commit(\.count, 10)commiting a change to the state is immediate.
Note: With the addition of @dyanmicMember and Self Keypath feature. You can now reference state from the store itself.
store.countervs
store.state.counterNote: Prestige supports Combine. When not using PromiseKit Prestige will fall back to Combine, only from iOS 13 and above, otherwise you must use PromiseKit
- iOS 12.0+
- macOS 10.14+
- Xcode 11.0+
Carthage is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks.
You can install Carthage with Homebrew using the following commands:
$ brew update
$ brew install carthageTo integrate Prestige into your Xcode project using Carthage, specify it in your Cartfile:
github "Prince2k3/prestige"
Run carthage update to build the framework and drag the built Prestige.framework into your Xcode project.
Prince Ugwuh, prince.ugwuh@gmail.com
Louis Daily, louisvdaily@gmail.com
Prestige is available under the MIT license. See the LICENSE file for more info.