Decoding structure use by SwiftyJson and Alamofire - swift

Question

How can I decode data to a structure using Alamofire and SwiftyJSON? My attempts give me errors like that
"No value associated with key CodingKeys(stringValue: \"user\",
intValue: nil)
Here is my code, my try doesn't give me the result when I use non-optional values, they respond to me with NIL values
Alamofire.request(url, method: .post, parameters: params, encoding: URLEncoding.default, headers: nil).responseJSON { (response) in
if response.data != nil {
switch response.result {
case.failure( let error):
print(error)
case.success(let val):
var json = JSON(val)
print(json)
guard let data = response.data else {return}
do {
let root = try JSONDecoder().decode(MainInfo.self, from: data)
print(root.submodel)
}
catch {
print("Bigerror")
print(error)
}
This is my structure
struct user: Codable {
var push_id:String?
var name:String?
var id:String?
var role_id:String?
var taxi_park_id:Int?
var car_number:String?
enum CodingKeys:String,CodingKey {
case push_id = "push_id"
case name = "name"
case id = "id"
case role_id = "role_id"
case taxi_park_id = "taxi_park_id"
case car_number = "car_number"
}
}
struct MainInfo : Decodable {
let model: String?
let submodel: String?
let user:user
enum CodingKeys:String,CodingKey {
case model = "model"
case submodel = "submodel"
case user = "user"
}
}
This is my pretty printed json
{
"facilities" : [
],
"model" : "AMC",
"taxi_park" : "Taxi +",
"submodel" : "Gremlin",
"user" : {
"role_id" : 2,
"push_id" : "dW7Cy-ItcDo:APA91bH62zJJKKz0t9VxP29H0iE2xhnQH0hDvKpGaHc5pknuTuZq2lMaj-EapQlN3O4dJF0ysSuCNOeb-2SdJaJaLIZcwHD3CCpeNpz6UVeGktoCm2ykL2rNXF5-ofQckvz1xTvVO0V6",
"taxi_park_id" : 0,
"id" : 3,
"name" : "China",
"car_number" : "X123OOO"
}
}

Answer 1

First of all your question has nothing to do with SwiftyJSON as you are using Codable.
Second of all name the structs with starting capital letter (User), that avoids confusion like let user : user
The error is misleading. All .._id values except push_id are Int rather than String. It's very easy to distinguish strings from all other types: Strings are always wrapped in double quotes.
And if you pass the convertFromSnakeCase key decoding strategy you don't need CodingKeys at all
struct MainInfo : Decodable {
let model : String
let submodel : String
let user : User
}
struct User: Decodable {
let pushId : String
let name : String
let id : Int
let roleId : Int
let taxiParkId : Int
let carNumber : String
}
...
do {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let root = try decoder.decode(MainInfo.self, from: data)
print(root.submodel)
} catch { print(error) }

Answer 2

Try this code, also a simple tip, we use coding keys in swift because sometimes we have to receive an inconvenient parameter keys but we also want to use it simple and clearly in the struct therefore CodingKeys are helpful in your case you using CodingKeys to decode the same parameter name i added the following taxiPark propriety to give you a hint on why they are useful, for example: i want to parse a JSON that have a key called
Person_ID_From_School
with coding keys i can do that with a better naming simple as personId and so on
struct MainInfo : Decodable {
let model: String?
let submodel: String?
let user:user
let taxiPark: String?
let facilities: [String?]?
enum CodingKeys:String,CodingKey {
case model = "model"
case submodel = "submodel"
case user = "user"
case taxiPark = "taxi_park"
case facilities = "facilities"
}
}