Question 101536 in IOS Swift Question posted in
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Ios swift – how to create swift model for API response if response have "key" which have nil Value initially but its get filled with data type after sometime

this is my API response from postman when "status" key value is open

{
    "data": {
        "id": 247,
        "status": "open",
}
        "code": 1,
        "message": "Details fetched successfully."
}

and this is API response from same API when "status" key value get changed to "completed"


{
    "data": {
        "id": 247,
         "status": “completed,
        "additional_data": {
            "id": 241,
            "booking_id": 247,
            "checklist_done": "{"4":"Gear Oil","2":"Engine Oil Change"}",
            "work_with_price": "{}",
            "work_price": "0",
            "status": "pending"
      },
    
    "code": 1,
    "message": "Details fetched successfully."
}

so if you look on above response a new key "additional_data" get added to response. what is the problem i am facing when "status" is "open" i am able to decode data but when "status" changed to "completed" i am not able to decode data

here what i had tried
this is structure which i have created to decode API response

struct ServicingModel: Codable {
    var data: DataClass?
    var code: Int?
    var message: String?
}


struct DataClass: Codable {
    var id: Int?
    var status: String?
    var additionalData: AdditionalData?

 enum CodingKeys: String, CodingKey {
        case id
        case status 
        case additionalData = "additional_data"
   }

init(from decoder: Decoder) throws {
            let values = try decoder.container(keyedBy: CodingKeys.self)
            id = try values.decodeIfPresent(Int.self, forKey: .id)
            status = try values.decodeIfPresent(String.self, forKey: .status)

            if let additionalDataOpt = try values.decodeIfPresent(AdditionalData.self,        forKey: .additionalData) {
                additionalData = additionalDataOpt
            } else {
                additionalData = nil
            }
}

}

struct AdditionalData: Codable {
    var id, bookingID: Int?
    var checklistDone: String?
    var workWithPrice: String?
    var workPrice: String?
    var status: String?

enum CodingKeys: String, CodingKey {
        case id
        case bookingID = "booking_id"
        case checklistDone = "checklist_done"
        case workWithPrice = "work_with_price"
        case workPrice = "work_price"
        case status
}
}

by using above structure i am able to decode data when status is open but when status is changed to completed i am unable to decode data, please guide me how i can create model to for additional data to map API response when additional_data key get added.

i got stuck on this problem from last three days any help would be appreciated . thanks for advance

Tags:

2

Answers


  1. 0

    The JSON you shared is not a valid JSON, but this should work for you if i am getting the question right.

    // MARK: - MyModel
    struct MyModel: Codable {
        let data: DataClass?
        let code: Int?
        let message: String?
    }
    
    // MARK: - DataClass
    struct DataClass: Codable {
        let id: Int?
        let status: String?
        let additionalData: AdditionalData?
    
        enum CodingKeys: String, CodingKey {
            case id, status
            case additionalData = "additional_data"
        }
    }
    
    // MARK: - AdditionalData
    struct AdditionalData: Codable {
        let id, bookingID: Int?
        let checklistDone, workWithPrice, workPrice, status: String?
    
        enum CodingKeys: String, CodingKey {
            case id
            case bookingID = "booking_id"
            case checklistDone = "checklist_done"
            case workWithPrice = "work_with_price"
            case workPrice = "work_price"
            case status
        }
    }
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  2. 0

    Notes:

    • As mentioned by others the JSON is invalid.
    • As you decode additionalData with decodeIfPresent, an if statement is not needed. If the key is missing decodeIfPresent returns nil.
    • Declare only those properties as optional whose key can be missing.
    • If you don’t need to encode the data conform only to Decodable.
    • If the properties won’t be modified, declare them as let constants.
    • A good practice is to decode status as enum.
    • You can get rid of the CodingKeys in AdditionalData and the conversion = "additional_data" by applying the convertFromSnakeCase key decoding strategy.
    struct ServicingModel: Decodable {
    var data: DataClass
    var code: Int
    var message: String
}

enum Status: String, Decodable {
    case open, completed
}

struct DataClass: Decodable {
    let id: Int
    let status: Status
    let additionalData: AdditionalData?
    
    enum CodingKeys: String, CodingKey {
        case id, status, additionalData
    }
    
    init(from decoder: Decoder) throws {
        let values = try decoder.container(keyedBy: CodingKeys.self)
        id = try values.decode(Int.self, forKey: .id)
        status = try values.decode(Status.self, forKey: .status)
        additionalData = try values.decodeIfPresent(AdditionalData.self, forKey: .additionalData)
    }
}

struct AdditionalData: Decodable {
    let id, bookingId: Int
    let checklistDone, workWithPrice, workPrice, status: String
}

    let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
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