Core data NSManagedObject convert to json format - core-data

Question

Hi guys I need your help I am new in swift language now I Stuck here I need json like this format from core data result. thanks in advance
Core Data Function return this result and I want to convert this result info json format
func GetAttendance()->[Tbl_Attendance]
{
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Tbl_Attendance")
do {
let fetchedAttendance = try context.fetch(fetchRequest) as! [Tbl_Attendance]
return fetchedAttendance
} catch {
fatalError("Failed to fetch Tbl_Attendance: \(error)")
}
}
I need to convert like this
{
"students": [
{
"id": 12345,
"name": "Giuseppe",
"lastName": "Lanza",
"age": 31
}
]
}

Answer 1

Create extension to Tbl_Attendance and make it implement Encodable
Create enum CodingKeys: String, CodingKey {...} in extension containing all attributes to encode
Implement public func encode(to encoder: Encoder) in extension
From somewhere in your code perform encoding
Example
extension Tbl_Attendance: Encodable {
enum CodingKeys: String, CodingKey {
case prop1
case prop2
}
public func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(prop1, forKey: .prop1)
try container.encode(prop2, forKey: .prop2)
}
}
//perform encoding somewhere in your code
let arr: GetAttendance()
let encoder = JSONEncoder()
do {
let json = try encoder.encode(arr)
//print(String(data: json, encoding: .utf8)!)
} catch {
print("JSON error \(error)")
}