Decodable value String or Bool

0
votes

I'm currently working with a bad designed JSON Api... This returns always a value (eg. String, Int, Double...) or false(not null).

What is the best way to handle this with decodable, as Any is not supported by Codable?

A key can look like this:

{
    "key": "Test",
}

Or like this(I know, should be null instead of false):

{
    "key": false,
}

And this is not possible:

struct Object: Decodable {
    let key: Any?
}
2
iosswiftcodable
what is your problem? does your API return back unpredictable types, or what? - holex
Not my API... But It returns false instead of null, when the value is empty... - Urkman
I think you can try setting your let key as Decodable? and then you have to cast your key to your type - Francesco Deliro

2 Answers

2
votes

You can create a generic wrapper type which assign nil to an Optional value if the value for a key is false, otherwise it decodes the value. Then instead of storing the actual types, you can wrap them in this wrapper.

struct ValueOrFalse<T:Decodable>: Decodable {
    let value:T?

    public init(from decoder:Decoder) throws {
        let container = try decoder.singleValueContainer()
        let falseValue = try? container.decode(Bool.self)
        if falseValue == nil {
            value = try container.decode(T.self)
        } else {
            value = nil
        }
    }
}

struct RandomJSONStruct: Decodable {
    let anInt:ValueOrFalse<Int>
    let aString:ValueOrFalse<String>
}

let noValueJson = """
{
    "anInt": false,
    "aString": "Test"
}
"""

do {
    print(try JSONDecoder().decode(RandomJSONStruct.self, from: noValueJson.data(using: .utf8)!))
} catch {
    print(error)
}
0
votes

I have same situation where ID can be Int or String 

class MyClass: Codable {
    let id: Int?
    required init(from decoder: Decoder) throws {
       let values = try decoder.container(keyedBy: CodingKeys.self)

       do {
           let stringId = try values.decodeIfPresent(String.self, forKey: .id)
            id = Int(stringId ?? "0")

          } catch {
             id = try values.decodeIfPresent(Int.self, forKey: .id)

         }
    }

  }

Inside required init(from decoder: Decoder) throws I have another do try block in which I convert it