Can we make the Codable key in struct as case insensitive in Swift

Question

Can we make the Codable key case insensitive? NOT VALUE but the KEY ITSELF needs to be case insensitive

struct Model: Codable, Equatable {
let number: String?
let id: String?
let address: String?

enum CodingKeys: String, CodingKey {
case number = "A-Number"
case id = "A-Id"
case address = "AddressId"
}
}

So that it works for both json:

Sample Json 1
{
"A-Number" : "12345",
"A-Id" : "1",
"AddressId" : "3456"
}

Sample Json 2
{
"a-number" : "12345",
"a-id" : "1",
"addressid" : "3456"
}

Answer 1

use the below code for making the keys lowercase, so that you can use throught your application. NOTE: All your keys will be lowercased with this solution, if you want to use them.

struct AnyKey: CodingKey {
      var stringValue: String

      init?(stringValue: String) {
        self.stringValue = stringValue
      }

      var intValue: Int? {
        return nil
      }

      init?(intValue: Int) {
        return nil
      }
    }
    
    struct DecodingStrategy {
        static var lowercase: ([CodingKey]) -> CodingKey {
            return { keys -> CodingKey in
                let key = keys.first!
                let modifiedKey = key.stringValue.prefix(1).lowercased() + key.stringValue.dropFirst()
                return AnyKey(stringValue: modifiedKey)!
            }
        }
    }

To use this:

let jsonDecoder = JSONDecoder()
jsonDecoder.keyDecodingStrategy = .custom(DecodingStrategy.lowercase)
let dataModel = try jsonDecoder.decode(YourDataModel, from: yourdata)