Swift + Core Data only saving last in loop. [duplicate] - ios

Question

This question already has answers here:
Core Data in Swift: Only saving last object in a for loop
(4 answers)
Closed 5 years ago.
I am trying the most basic of core data implementations and for some reason, I cannot seem to get it to work.
I am getting the data from a json file on a server and saving the data like so:
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
let users = NSEntityDescription.insertNewObject(forEntityName: "Users", into: context)
Alamofire.request(jsonLocation).responseJSON { (responseData) -> Void in
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
for (_, value) in swiftyJsonVar {
let name = value["name"].stringValue
let age = value["age"].stringValue
//print("User: \(name)(\(age)).")
users.setValue(name, forKey: "name")
users.setValue(rank, forKey: "age")
do {
try context.save()
print("Saved..... ")
} catch {
print("save error")
}
}
} else {
print("response is nil")
}
}
When I try to view the data using:
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Users")
request.returnsObjectsAsFaults = false
do {
let results = try context.fetch(request)
if results.count > 0 {
for result in results as! [NSManagedObject] {
if let userName = result.value(forKey: "name") as? String {
print(userName)
}
}
} else {
print("no records found")
}
} catch {
print("did not get")
}
The console prints
Xander
Which is the last name in a list of 20. Any ideas?

Answer 1

You need to call NSEntityDescription.insertNewObject for each user. You are only calling it once.
Change your code to:
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
Alamofire.request(jsonLocation).responseJSON { (responseData) -> Void in
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
for (_, value) in swiftyJsonVar {
let name = value["name"].stringValue
let age = value["age"].stringValue
//print("User: \(name)(\(age)).")
let user = NSEntityDescription.insertNewObject(forEntityName: "Users", into: context)
user.setValue(name, forKey: "name")
user.setValue(rank, forKey: "age")
}
do {
try context.save()
print("Saved..... ")
} catch {
print("save error")
}
} else {
print("response is nil")
}
}