alamofire-evolution-after.swift

func getUsers(complete: @escaping (_ success: Bool, _ users: [User]?, _ error: Error?) -> ()) -> Request {
    return alamoFireManager
        .request("https://myserver.com/",
                 method: .get,
                 parameters: nil,
                 encoding: JSONEncoding.default,
                 headers: nil)
        .validate(statusCode: 200..<500)
        .responseJSON(completionHandler: { (response) in
            switch response.result {
            case .success(let data):
                switch response.response?.statusCode {
                case 200, 204:
                    /// Handle success, parse JSON data
                    do {
                        let users = try JSONDecoder().decode([Users].self, from: JSONSerialization.data(withJSONObject: data))
                        complete(true, users, nil)
                    } catch let error {
                        /// Handle json decode error
                        complete(false, nil, Error())
                    }
                case 429:
                    /// Handle 429 error
                    complete(false, nil, Error(code: 429))
                default:
                    /// Handle unknown error
                    complete(false, nil, Error(code: -1))
                }
            case .failure(let error):
                /// Handle request failure
                complete(false, nil, Error(code: 0))
            }
        })
}