brentmifsud/asyncvalue

A simple swift package that provides a Swift Concurrency equivalent to `@Published`.

asyncvalue's Issues

[Feature] automatic trigger for `objectWillChange` publisher

Remembering to add a willSet to all of your async value properties is not all that user friendly. I think we can do better:

Proposed Solution:

// this might not be needed with the new swift 5.7 generics. Will investigate. When Xcode 14 is released.
internal protocol AnyAsyncValue {
     var projectedValue: AsyncSequence<Any>
}

internal extension AsyncValue: AnyAsyncValue {
    var projectedValue: AsyncSequence<Any> {
        projectedValue
    }
}

@MainActor open class AsyncObservableObject: ObservableObject {
    private var objectWillChangeTasks: [Task<Void, Never>] = []
    
    init() {
         setupObjectWillChangeTasks()
    }

    deinit {
        for task in objectWillChangeTasks {
            task.cancel()
        }
    }

    private func setupObjectWillChangeTasks() {
        let mirror = Mirror(reflecting: self)

        for child in mirror.children {
              if let asyncValue = child.value as? AnyAsyncValue {
                  let task = Task {
                       for await _ in asyncValue.projectedValue {
                           objectWillChange.send()
                       }
                  }

                  objectWillChangeTasks.append(task)
              }
        } 
    }
}