How to map dynamic properties in model class (Swift) - json

Question

I am new to IOS Development, i came across a really interesting situation, i have this json response coming server side
{
"caps": {
"first_key": "34w34",
"first_char": "34w45",
"first_oddo": "34w34"
.... : .....
.... : .....
}
}
My issue this that keys inside "caps" object can be dynamic (like what if one more value is added). I am using ObjectMapper to mapper to map values from response to model class. I have this model class
class User: Mappable {
var first_key: String?
var first_char: String?
var first_oddo: String?
required init?(map: Map) {
}
// Mappable
func mapping(map: Map) {
first_key <- map["first_key"]
first_char <- map["first_char"]
first_oddo <- map["first_oddo"]
}
}
Now as i dont know how to populate my model if values in json response are changed (because that are dynamic). I hope i have explained it well. I think i dont want hard coded values inside model?

Answer 1

This solution uses the Codable protocol introduced with Swift 4.
If the keys of your JSON are dynamic then you need a Dictionary.
JSON
Given this JSON
let data = """
{
"caps": {
"first_key": "34w34",
"first_char": "34w45",
"first_oddo": "34w34"
}
}
""".data(using: .utf8)!
The Response Model
You can define a struct like this
struct Response:Codable {
let caps: [String:String]
}
Decoding 🎉🎉🎉
Now you can decode your JSON
if let response = try? JSONDecoder().decode(Response.self, from: data) {
print(response.caps)
}
Output
["first_key": "34w34", "first_oddo": "34w34", "first_char": "34w45"]