0x0c/StaticPublished

StaticPublished is Swift Macro to avoid boilerplate codes that observe changes of static variables.

StaticPublished

StaticPublished is Swift Macro to avoid boilerplate codes to observe changes of static variables.

import Combine
import StaticPublished

struct Example {
    // Adding @StaticPublished macro to observe changes of the static variable.
    @StaticPublished
    static var input: Int = 10
}

// @StaticPublished generates `static let inputPublisher: AnyPublisher<Int, Never>`
// and we can observe changes of `input`.
var cancellable = Set<AnyCancellable>()
Example.inputPublisher.sink { newValue in
    print("receive \(newValue)")
}.store(in: &cancellable)

@StaticPublished expands this code

@StaticPublished
static var input: Int = 0

to below.

static var input: Int = 0 {
    didSet {
        _inputSubject.send(input)
    }
}

private static let _inputSubject = PassthroughSubject<Int, Never>()

static let inputPublisher = _inputSubject.eraseToAnyPublisher()