swift Decodable 使用遇到的问题

最近使用swift开发，用原生的Decodable将json转换为模型，遇到了一些问题，在这里做个记录 。

1.某个字段类型可变

某个字段有时候为Int,有时候为String
当dataType=1时为valueString类型，当dataType = 2时value为Int类型
处理办法： 将 value 声明为String？类型重写 init(from decoder: Decoder)方法 示例代码如下

struct SmartControlModelTemplateAttributeValueModel {
  var dataType: Int
  var displayName: String
  var value: String?

  init(dataType: Int, displayName: String, value: String?) {
    self.dataType = dataType
    self.displayName = displayName
    self.value = value
  }
  init(from decoder: Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    dataType = try container.decode(Int.self, forKey: .dataType)
    displayName = try container.decode(String.self, forKey: .displayName)
    do {
      value = try String(container.decode(Int.self, forKey: .value))
    } catch DecodingError.typeMismatch {
      value = try container.decode(String.self, forKey: .value)
    }
  }
}

2. 模型嵌套

服务器返回json中有多个数组字典类型嵌套，字典键值类型不单一 如json：

解决方案： 将每一个模型映射 示例代码 ：

struct SmartControlModelTemplateModel {
  var deviceCategory: String
  var version: String
  var id: Int
  var deviceType: Int
  var deviceNodeType: Int
  var attributes: [SmartControlModelTemplateAttributesModel]
  //  var events: [SmartControlModelTemplateEventsModel]
}
extension SmartControlModelTemplateModel: Decodable{
  enum CodingKeys: String, CodingKey {
    case deviceCategory
    case version
    case id
    case deviceType
    case deviceNodeType
    case attributes
    //    case events
  }
}
struct SmartControlModelTemplateAttributesModel {
  var code: String
  var displayName: String
  var description: String
  var readWriteMode: Int
  var custom: Int
  var direction: Int
  var dataType: Int
  var value:[SmartControlModelTemplateAttributeValueModel]?
  var setup:SmartControlModelTemplateAttributeSetupModel?
}
extension SmartControlModelTemplateAttributesModel: Decodable{
  enum CodingKeys: String, CodingKey {
    case code
    case displayName
    case description
    case readWriteMode
    case custom
    case direction
    case dataType
    case value
    case setup
  }
}
struct SmartControlModelTemplateAttributeValueModel {
  var dataType: Int
  var displayName: String
  var value: String?

  init(dataType: Int, displayName: String, value: String?) {
    self.dataType = dataType
    self.displayName = displayName
    self.value = value
  }
  init(from decoder: Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    dataType = try container.decode(Int.self, forKey: .dataType)
    displayName = try container.decode(String.self, forKey: .displayName)
    do {
      value = try String(container.decode(Int.self, forKey: .value))
    } catch DecodingError.typeMismatch {
      value = try container.decode(String.self, forKey: .value)
    }
  }
}

extension SmartControlModelTemplateAttributeValueModel: Decodable{
  enum CodingKeys: String, CodingKey {
    case dataType
    case displayName
    case value
  }
}
struct SmartControlModelTemplateAttributeSetupModel {
  var max: String
  var min: String
  var step: String
  var unit: String
  var unitName: String
}
extension SmartControlModelTemplateAttributeSetupModel: Decodable{
  enum CodingKeys: String, CodingKey {
    case max
    case min
    case step
    case unit
    case unitName
  }
}

没怎么写过文档，看的老铁请轻喷