json - Swift Decodable 的可失败初始化器

Question

我正在尝试解析以下 json 模式，海报可能为空也可能不为空

{
  "poster": {},
  "recommends": []
}

我的可解码类如下:

public struct RecommendedList: Decodable {
    public let poster: Poster?
    public let recommends: [Recommend]
}

public struct Poster: Decodable {
    public let backgroundImage: URL
    public let topImage: URL
    public let windowImage: URL
    public let windowSkinImagePath: URL
    public let deeplink: URL

    public init(from decoder: Decoder) throws {
        // I want a failable intializer not one that throws
    }
}

我的问题是如何让海报成为可选的？我的想法是我需要一个可失败的初始化程序，但 decodable 需要一个抛出的初始化程序。

Answer 1

所以看起来我需要添加一个尝试？在推荐列表中 init(from decoder:)

public struct RecommendedList: Decodable {
    public let poster: Poster?
    public let recommends: [Recommend]

    enum CodingKeys: String, CodingKey {
        case poster
        case recommends
    }

    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        poster = try? container.decode(Poster.self, forKey: .poster)
        recommends = try container.decode([Recommend].self, forKey: .recommends)
    }
}