parsing nested json issue - json

Question

I am new here and I am parsing json which is array in side array so I can't understand how get inside array from json let me show you my json.
JSON
{
"subject_list" = (
{
"con_id" = 2;
"level_id" = 1;
"sub_id" = 4;
"sub_list" = (
{
"ch_id" = 17;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1530600693.jpg";
"ch_name" = " 01. Measurement";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 4;
},
{
"ch_id" = 23;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1451930609.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 4;
},
{
"ch_id" = 24;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1884777188.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 4;
},
{
"ch_id" = 25;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1518702048.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 4;
}
);
"sub_name" = Physics;
},
{
"con_id" = 2;
"level_id" = 1;
"sub_id" = 8;
"sub_list" = (
{
"ch_id" = 26;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1437196139.jpg";
"ch_name" = " 1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 8;
},
{
"ch_id" = 27;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1903171865.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 8;
}
);
"sub_name" = Chemistry;
},
{
"con_id" = 2;
"level_id" = 1;
"sub_id" = 9;
"sub_list" = (
{
"ch_id" = 31;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1319333294.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 9;
}
);
"sub_name" = Testing;
},
{
"con_id" = 2;
"level_id" = 1;
"sub_id" = 10;
"sub_list" = (
{
"ch_id" = 28;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1373218664.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 10;
}
);
"sub_name" = "Test Subject";
},
{
"con_id" = 2;
"level_id" = 1;
"sub_id" = 11;
"sub_list" = (
{
"ch_id" = 29;
"ch_image" = "http://mobileapp.xmeducation.com/upload/246189282.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 11;
}
);
"sub_name" = "Test Subject 1";
},
{
"con_id" = 2;
"level_id" = 1;
"sub_id" = 12;
"sub_list" = (
{
"ch_id" = 30;
"ch_image" = "http://mobileapp.xmeducation.com/upload/1342731807.jpg";
"ch_name" = "1. Test Chapter";
"con_id" = 2;
"level_id" = 1;
"sub_id" = 12;
}
);
"sub_name" = "Test Subject 2";
}
);
this is my JSON and I want sub_list array from subject_list I have done some code let me show you.
CODE
func callSubChapAPI(){
let preferences = UserDefaults.standard
let studentlvl = "student_lvl"
let student_lvl = preferences.object(forKey: studentlvl) as! String
print(student_lvl)
let params = ["level_id": student_lvl]
Alamofire.request(subListWithChapter, method: .post, parameters: params).responseJSON(completionHandler: {(response) in
switch response.result{
case.success(let data):
print(data)
let json = JSON(data)
print(json)
do {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let subjects = try decoder.decode(SubjectResponse.self, from: data as! Data)
print(subjects)
} catch {
print(error)
}
case.failure(let error):
print(error.localizedDescription)
}
})
}
here is my struct:
struct sub_list {
let ch_id : Int
let ch_image: String
let ch_name: String
let con_id: String
let level_id: String
let sub_id: String
}
Please see my code and json format please tell me how to get sub_list array from json please hell me and thanks in advance.

Answer 1

Actually subject_list is also an array so you need to iterate that as well.
let data = json["subject_list"]
print(data)
data.array?.forEach({ (subject) in
subject["sub_list"].array?.forEach({ (chapList) in
let chapter = sub_list(ch_id: chapList["ch_id"].intValue, ch_image: chapList["ch_image"].stringValue, ch_name: chapList["ch_name"].stringValue, con_id: chapList["con_id"].stringValue, level_id: chapList["level_id"].stringValue, sub_id: chapList["sub_id"].stringValue)
print(chapter)
self.chapListData.append(chapter)
})
})
self.collView.reloadData()
Recommendation
It's not worth adding any dependency for json parsing when you already have Apple provided Codable. It will reduce much of your boilerplate code added because of SwiftyJSON.
Below is a complete example for your current api,
struct SubjectResponse: Decodable {
let subjectList: [Subject]
}
struct Subject: Decodable {
let subList: [Chapter]
}
struct Chapter: Decodable {
let chId : Int
let chImage: String
let chName: String
let conId: Int
let levelId: Int
let subId: Int
}
Alamofire.request(subListWithChapter, method: .post, parameters: params).responseData() { (response) in
switch response.result {
case .success(let data):
do {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let subjects = try decoder.decode(SubjectResponse.self, from: data)
print(subjects)
} catch {
print(error)
}
case .failure(let error):
print(error.localizedDescription)
}
}