Extract and decode json data using Decodable in swift

Question

I'm using an external framework for showing message list and detail screen.

Framework internal Message model which we can't modify:

public struct Message: Decodable, Encodable {
    public var id: String?
    public var title: String?
    public var subTitle: String?
    public var status: String?
}

Our API response:

{ 
   "data":{ 
      "custId":"1234",
      "type":"premium",
      "totalCount":"100",
      "msgList":[ 
         { 
            "id":"1",
            "title":"Main Title",
            "subTitle":"Sub title",
            "status":"R"
         },
         { 
            "id":"2",
            "title":"Main Title",
            "subTitle":"Sub title",
            "status":"R"
         }
      ],
      "categoryCount":"50"
   }
}

How I can extract msgList array from JSON response and decode to Message model.

Something like only passing list data/json:

let responseMessage = try JSONDecoder().decode([Message.self], from: list)

Appreciate your help and suggestion!

Thanks

Answer 1

You have to create the payload structure.

struct Data: Decodable {
    struct Payload: Decodable {
        let msgList: [Message]
    }

    let data: Payload
}

Decode JSON using JSONDecoder.

let responseMessage = try JSONDecoder().decode([Message.self], from: list)

messageList can access using : responseMessage.data.msgList