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swift 4可编码-api有时提供int有时提供string

codable swift4 api swift

1

Nxt97 · 技术社区 · 7 年前

我现在有密码了。但是api有一些字符串项,有时可以有 Int 价值 0 如果它们是空的。我在这里搜索发现了这个: Swift 4 Codable - Bool or String values 但我不能让它运行

我的结构

struct check : Codable {
    let test : Int
    let rating : String?  
}

评级通常是 "1Star" . 但如果没有评分我会得到 零 作为int返回。

我正在这样分析数据:

enum Result<Value> {
    case success(Value)
    case failure(Error)
}

func checkStar(for userId: Int, completion: ((Result<check>) -> Void)?) {
    var urlComponents = URLComponents()
    urlComponents.scheme = "https"
    urlComponents.host = "xyz.com"
    urlComponents.path = "/api/stars"
    let userIdItem = URLQueryItem(name: "userId", value: "\(userId)")
    urlComponents.queryItems = [userIdItem]
    guard let url = urlComponents.url else { fatalError("Could not create URL from components") }

    var request = URLRequest(url: url)
    request.httpMethod = "GET"


    let config = URLSessionConfiguration.default
    config.httpAdditionalHeaders = [
        "Authorization": "Bearer \(keytoken)"
    ]

    let session = URLSession(configuration: config)
    let task = session.dataTask(with: request) { (responseData, response, responseError) in
        DispatchQueue.main.async {
            if let error = responseError {
                completion?(.failure(error))
            } else if let jsonData = responseData {
                // Now we have jsonData, Data representation of the JSON returned to us
                // from our URLRequest...

                // Create an instance of JSONDecoder to decode the JSON data to our
                // Codable struct
                let decoder = JSONDecoder()

                do {
                    // We would use Post.self for JSON representing a single Post
                    // object, and [Post].self for JSON representing an array of
                    // Post objects
                    let posts = try decoder.decode(check.self, from: jsonData)
                    completion?(.success(posts))
                } catch {
                    completion?(.failure(error))
                }
            } else {
                let error = NSError(domain: "", code: 0, userInfo: [NSLocalizedDescriptionKey : "Data was not retrieved from request"]) as Error
                completion?(.failure(error))
            }
        }
    }

    task.resume()
}

加载:

func loadStars() {
    checkStar(for: 1) { (result) in
        switch result {
        case .success(let goo):
            dump(goo)
        case .failure(let error):
            fatalError(error.localizedDescription)
        }
    }
}

我希望有人能帮我,因为我不完全确定这种解析是如何工作的。

1 回复 | 直到 7 年前

1

3

vg0x00 7 年前

您可以实现自己的decode init方法,从decode container中获取每个类属性,在这一节中,使您处理“rating”是int还是string的逻辑,最后对所有必需的类属性进行签名。

以下是我制作的一个简单演示:

class Demo: Decodable {
    var test = 0
    var rating: String?

    enum CodingKeys: String, CodingKey {
        case test
        case rating
    }

    required init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        let test = try container.decode(Int.self, forKey: .test)
        let ratingString = try? container.decode(String.self, forKey: .rating)
        let ratingInt = try? container.decode(Int.self, forKey: .rating)
        self.rating = ratingString ?? (ratingInt == 0 ? "rating is nil or 0" : "rating is integer but not 0")
        self.test = test
    }
}

let jsonDecoder = JSONDecoder()
let result = try! jsonDecoder.decode(Demo.self, from: YOUR-JSON-DATA)

如果rating api的值是普通字符串,您将得到它。
如果等级API的值为0,则等级将等于“等级为零或0”
如果rating api的值是其他整数,则rating将是“rating is integer but not 0”

你可以修改解码的“评分”结果,这应该很容易。

希望这能给你点帮助。:)

更多信息: Apple's encoding and decoding doc