working with similar json objects, casting int to string [duplicate] - ios

Question

This question already has answers here:
Using codable with value that is sometimes an Int and other times a String
(5 answers)
Closed last year.
i am working with a service that have both a websocket for live data and a api for historical data
the JSON looks similar and i would like to decode it to the same object
the only difference is that in the live one variable is a number but as a string and with the historical data the number is an int.
and preferably i would like to not have to create 2 almost identical decodable objects.
have anyone tried something similar.

Answer 1

You have to define a single type (Int or String) for your data structure and use init with Decoder to make a custom parsing.
struct MyData: Decodable {
let value: Int // Could be Int or String from different services
}
extension MyData {
enum CodingKeys: String, CodingKey {
case value
}
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
do {
value = try container.decode(Int.self, forKey: .value)
} catch {
let stringValue = try container.decode(String.self, forKey: .value)
if let valueInt = Int(stringValue) {
value = valueInt
} else {
var codingPath = container.codingPath
codingPath.append(CodingKeys.value)
let debugDescription = "Could not create Int from String \(stringValue) of field \(CodingKeys.value.rawValue)"
let context = DecodingError.Context(codingPath: codingPath, debugDescription: debugDescription)
throw DecodingError.dataCorrupted(context)
}
}
}
}

Answer 2

I think you need a wrapper for that case of some sort. To make it as convenient as possible you could use a property wrapper for this
#propertyWrapper
struct NormalOrStringyInt: Decodable {
var wrappedValue: Int?
init(from decoder: Decoder) throws {
let container = try decoder.singleValueContainer()
if let value = try? container.decode(Int.self) {
wrappedValue = value
} else if
let string = try? container.decode(String.self),
let value = Int(string)
{
wrappedValue = value
} else {
wrappedValue = nil // default value
}
}
}
struct Model: Codable {
#NormalOrStringyInt var id: Int?
var someInt: Int
var someString: String
...
}
let model = try! JSONDecoder().decode(Model, from: data)
let id: Int? = model.id.wrappedValue