Middleware promise

[vadymmarkov]

"Middleware" is the function which works with the first promise in the chain, before the actual request. It could be used to prepare networking, do some kind of pre-processing task, cancel request under particular conditions, etc.

For example, in the combination with https://github.com/hyperoslo/OhMyAuth

// In your configuration
// Remember to `resolve` or `reject` the promise
networking.middleware = { promise in
  AuthContainer.serviceNamed("service")?.accessToken { accessToken, error in
    if let error == error {
      promise.reject(error)
      return
    }

    guard let accessToken = accessToken else {
      promise.reject(CustomError())
      return
    }

    self.networking.authenticate(bearerToken: accessToken)
    promise.resolve()
  }
}

// Send your request like you usually do
networking.GET(request)
  .validate()
  .toJSONDictionary()

[viktorgardart]

Awesome work 👍 🎉

[vadymmarkov]

Thanks @viktorgardart I hope it will solve the problem you've explained in https://github.com/hyperoslo/Malibu/issues/42

[vadymmarkov]

@zenangst I think it's ready to merge.

[zenangst]

@vadymmarkov