我正在编写一个REST Web应用程序客户端,我使用的JSON看起来像这样:
JSON1
{
"device" : "iPhone"
"manufacturer" : "Apple"
"id" : 42
"owner" : "Steve"
}
但API也可以给我这种JSON
JSON2
{
"device" : "iPhone"
"manufacturer" : "Apple"
"id" : 42
"latitude" : 3.1415926535
"longitude" : 2.7182818284
}
所以现在在我的应用程序中,我创建了一个符合Codable协议的结构
struct MyStruct : Codable {
var name: String
var manufacturer: String
var owner: String?
// I prefer to use a property of type Location rather than 2 variables
var location: Location? {
guard let latitude = latitude, let longitude = longitude else {
return nil
}
return Location(latitude: latitude, longitude: longitude)
}
// Used to conform to the Codable protocol
private var latitude: Double?
private var longitude: Double?
}
struct Location {
var latitude: Double = 0.0
var longitude: Double = 0.0
}
这种架构有效但在我看来并不是最好的或优雅的。你知道一个更好的方法吗? 存在?我应该使用2个不同的json模型,而不是:
struct MyStruct1 : Codable {
var name: String
var manufacturer: String
var owner: String
}
struct MyStruct2 : Codable {
var name: String
var manufacturer: String
private var latitude: Double
private var longitude: Double
}
我是REST API客户端的新手,这种JSON似乎没有使用好的架构。
答案 0 :(得分:1)
制作owner
,latitude
& longitude
属性可选。
并使用decodeIfPresent
仅在属性存在时对其进行解码。
您可以创建struct
as-
struct UserData: Codable {//Confroms to Codable protocol
var id: Int
var device: String
var manufacturer: String
var owner: String? = nil//Making property optional
var latitude: Double? = nil//Making property optional
var longitude: Double? = nil//Making property optional
init(from decoder: Decoder) throws {
let values = try decoder.container(keyedBy: CodingKeys.self)
id = try values.decode(Int.self, forKey: .id)
device = try values.decode(String.self, forKey: .device)
manufacturer = try values.decode(String.self, forKey: .manufacturer)
owner = try values.decodeIfPresent(String.self, forKey: .owner)
latitude = try values.decodeIfPresent(Double.self, forKey: .latitude)
longitude = try values.decodeIfPresent(Double.self, forKey: .longitude)
}
}
示例Json:
let jsonExample = """
{
"device" : "iPhone",
"manufacturer" : "Apple",
"id" : 42,
"owner" : "Steve"
}
""".data(using: .utf8)!
let jsonExample2 = """
{
"device" : "iPhone",
"manufacturer" : "Apple",
"id" : 42,
"latitude" : 3.1415926535,
"longitude" : 2.7182818284
}
""".data(using: .utf8)!.
用法:
//Decode struct using JSONDecoder
let jsonDecoder = JSONDecoder()
do {
let modelResult = try jsonDecoder.decode(UserData.self,from: jsonExample2)
print("owner is \(String(describing: modelResult.owner)) - latitude is \(String(describing: modelResult.latitude)) - longitude is \(String(describing: (modelResult.longitude)))")
} catch {
print(error)
}