如何从 SwiftUI 中的 URLSession 获取响应

Question

我正在尝试在 SwiftUI 中构建一个 URLSession 来处理基于 API 令牌的身份验证，以登录到 web 应用程序。

我能够让 API 在 Postman 中正常工作，但无法在 SwiftUI 中获得任何类型的可读响应。 我是 SwiftUI 和调试新手。 从我处理授权的 web 服务器的日志来看，似乎来自我的 Swift 代码的登录请求是成功的，但我似乎无法解析出正文或标题。

我在 canvas 中不断收到“LoginResponse（消息：nil）”。

这是我的 SwiftUI 代码简化为仅尝试打印 URLSession 响应。

import Foundation

enum AuthenticationError: Error {
    case invalidCredentials
    case custom(errorMessage: String)
}

struct LoginRequestBody: Codable {
    let email: String
    let password: String
}

struct LoginResponse: Codable {
    let message: String?
}

class Sessionservice {
    
    func login(emailAddress: String, password: String, completion: @escaping (Result<String, AuthenticationError>) -> Void){
        
        guard let url = URL(string: "https://www.example.com/api/v1/auth/sign_in") else {
            completion(.failure(.custom(errorMessage:"Site is unavailable.  Try again later.")))
            return
        }
        
        let body = LoginRequestBody(email: "email@example.com", password: "password")
        
        
        var request = URLRequest(url: url)
                request.httpMethod = "POST"
                request.addValue("application/json", forHTTPHeaderField: "Content-Type")
                request.httpBody = try? JSONEncoder().encode(body)

                
                URLSession.shared.dataTask(with: request) { (data, response, error) in
                    
                    guard let data = data, error == nil else {
                        completion(.failure(.custom(errorMessage: "No data")))
                        return
                    }
                    
                    try! JSONDecoder().decode(LoginResponse.self, from: data)

                    guard let loginResponse = try? JSONDecoder().decode(LoginResponse.self, from: data) else {
                        completion(.failure(.custom(errorMessage: "loginResponse Failure")))
                        return
                    }
                    print(loginResponse)
                }.resume()
    }
}

Answer 1

import Foundation
import SwiftUI


enum AuthenticationError: Error {
case invalidCredentials
case custom(errorMessage: String)
}

struct LoginRequestBody: Codable {
let email: String
let password: String
}

struct LoginResponse: Decodable {
let data: LoginValue?
let success: Bool?
let client: String?
}

struct LoginToken: Decodable {
let token: String?
}

struct LoginValue: Decodable {
let message: String?
let user: UserRole?
let success: Bool?
}

struct UserRole: Decodable {
let role: String?
}

class Sessionservice {


func login(email: String, password: String, completion: @escaping (Result<String, AuthenticationError>) -> Void){

    guard let url = URL(string: "https://www.example.com/api/v1/auth/sign_in") else {
        completion(.failure(.custom(errorMessage:"Site is unavailable.  Try again later.")))
        return
    }
    
    let body = LoginRequestBody(email: email, password: password)
    
    
    var request = URLRequest(url: url)
            request.httpMethod = "POST"
            request.addValue("application/json", forHTTPHeaderField: "Content-Type")
            request.httpBody = try? JSONEncoder().encode(body)

            
            URLSession.shared.dataTask(with: request) { (data, response, error) in
                
                if let response = response as? HTTPURLResponse {

                    guard let token = response.value(forHTTPHeaderField: "Accesstoken") else {
                        completion(.failure(.custom(errorMessage: "Missing Access Token")))
                        return
                    }
                    completion(.success(token))
                }
                
                guard let data = data, error == nil else { return }
                guard let loginResponse = try? JSONDecoder().decode(LoginResponse.self, from: data) else { return }
                guard let messageData = loginResponse.data else {return}
                guard let message = messageData.message else {return}
                guard let userRole = messageData.user else {return}
                guard let role = userRole.role else {return}
                completion(.success(message))
                completion(.success(role))
               
            }.resume()
    
            
}
}