I've been using apple's guide for saving data in swift, but when I try to compile it's telling me that is isn't conforming. Based on apple's guide and other code it should be.
// MARK: NSCoding
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(firstName, forKey: "firstName")
aCoder.encodeObject(lastName, forKey: "lastName")
aCoder.encodeObject(phoneNumber, forKey: "phoneNumber")
aCoder.encodeObject(email, forKey: "email")
aCoder.encodeObject(address, forKey: "address")
}
required convenience init?(coder aDecoder: NSCoder) {
firstName = aDecoder.decodeObjectForKey("firstName") as! String
lastName = aDecoder.decodeObjectForKey("lastName") as! String
phoneNumber = aDecoder.decodeObjectForKey("phoneNumber") as! String
email = aDecoder.decodeObjectForKey("email") as! String
address = aDecoder.decodeObjectForKey("addressq") as! String
self.init(phoneNumber: phoneNumber, firstName: firstName, lastName: lastName, email: email, address: address)
}
So I'm simply not sure why it isn't conforming when I can run Apple's program fine.
EDIT: So the problem seems to be that I didn't have my class inherited from NSObject. That solved the problem.
No errors here:
class Dog {
var firstName: String
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(firstName, forKey: "firstName")
}
init(firstName: String) {
self.firstName = firstName
}
required convenience init?(coder aDecoder: NSCoder) {
let x = aDecoder.decodeObjectForKey("firstName") as! String
self.init(firstName: x)
}
}
var d = Dog(firstName: "Rover")
Related
I'm relatively new to iOS development in general, but I'm coding this app.
I have custom objects "Semester", "Course", and "Assignments". Semesters contain arrays of courses and courses contain arrays of assignments. I'm able to properly archive the semester and course information, but for some reason the assignment information can't be read.
Semester:
required init?(coder aDecoder: NSCoder) {
self.name = ""
super.init()
if let archivedName = aDecoder.decodeObject(forKey: "name") as? String {
name = archivedName
}
if let archivedCourses = aDecoder.decodeObject(forKey: "courses") as? [Course] {
courses = archivedCourses
}
}
func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: "name")
aCoder.encode(courses, forKey: "courses")
}
Course:
required init?(coder aDecoder: NSCoder) {
self.name = ""
super.init()
if let archivedName = aDecoder.decodeObject(forKey: "courseName") as? String {
name = archivedName
}
if let archivedAssignments = aDecoder.decodeObject(forKey: "assignments") as? [Assignment] {
assignments = archivedAssignments
}
}
func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: "courseName")
aCoder.encode(assignments, forKey: "assignments")
Assignment:
required init?(coder aDecoder: NSCoder) {
self.name = ""
self.grade = 0
self.weight = 0
super.init()
if let archivedName = aDecoder.decodeObject(forKey: "assignmentName") as? String, let archivedGrade = aDecoder.decodeObject(forKey: "assignmentGrade") as? Int, let archivedWeight = aDecoder.decodeObject(forKey: "assignmentWeight") as? Int {
name = archivedName
grade = archivedGrade
weight = archivedWeight
}
}
func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: "assignmentName")
aCoder.encode(grade, forKey: "assignmentGrade")
aCoder.encode(weight, forKey: "assignmentWeight")
}
I'm not sure why but the assignment details can't be read when I try to decode the object.
I Usually decode Int like this
if decoder.containsValue(forKey: "teamNumber"){
self.teamNumber = decoder.decodeInteger(forKey: "teamNumber")
}
translated to your issue will be like this, change the init?(coder aDecoder: NSCoder)method of your Assignment class
required init?(coder aDecoder: NSCoder) {
self.name = ""
self.grade = 0
self.weight = 0
super.init()
if let archivedName = aDecoder.decodeObject(forKey: "assignmentName") as? String{
self.name = archivedName
}
if decoder.containsValue(forKey: "assignmentGrade"){
self.grade = decoder.decodeInteger(forKey: "assignmentGrade")
}
if decoder.containsValue(forKey: "assignmentWeight"){
self.weight = decoder.decodeInteger(forKey: "assignmentWeight")
}
}
Hope this helps
When try to encode my custom object in iOS swift get this error from Xcode 8.3
unrecognized selector sent to instance 0x60800166fe80
*** -[NSKeyedArchiver dealloc]: warning: NSKeyedArchiver deallocated without having had -finishEncoding called on it.
And my code like this:
import UIKit
import Foundation
class Place: NSObject {
func setCustomObject(CustomObject obj:Any,Key key:String) {
let encodedObject : Data = NSKeyedArchiver.archivedData(withRootObject: obj)
UserDefaults.standard.set(encodedObject, forKey: key)
}
}
Here's an example how to make an object to conform to NSCoding. Basically you need to provide implementation of two methods - required convenience init?(coder decoder: NSCoder) and encode(with aCoder: NSCoder)
class Book: NSObject, NSCoding {
var title: String?
var pageCount: Int?
// Memberwise initializer
init(title: String,pageCount: Int) {
self.title = title
self.pageCount = pageCount
}
// MARK: NSCoding
// Here you will try to initialize an object from archve using keys you did set in `encode` method.
required convenience init?(coder decoder: NSCoder) {
guard let title = decoder.decodeObject(forKey: "title") as? String else { return nil }
self.init(title: title, pageCount: decoder.decodeInteger(forKey: "pageCount"))
}
// Here you need to set properties to specific keys in archive
func encode(with aCoder: NSCoder) {
aCoder.encode(self.title, forKey: "title")
aCoder.encodeCInt(Int32(self.pageCount), forKey: "pageCount")
}
}
Also I would recommend changing your setCustomObject method to this:
func setCustomObject(obj:NSCoding, key:String) {
let encodedObject : Data = NSKeyedArchiver.archivedData(withRootObject: obj)
UserDefaults.standard.set(encodedObject, forKey: key)
}
This way compiler prevent you passing NSKeyedArchiver an object that does not conform to NSCoding protocol.
If you don't want to provide all properties in the init method you can use default values:
init(title : String? = nil, pageCount: Int? = nil){
self.title = title
self.pageCount = pageCount
}
Now you can just init your object without any properties. Like that Book()
Here is the solutions, you have to implement the two methods
Encode Method
func encode(with aCoder: NSCoder)
Decoding method
required init?(coder aDecoder: NSCoder)
Complete Example code
class User: NSObject , NSCoding
{
var userID : Int = 0
var name : String = ""
var firstName : String = ""
var lastName : String = ""
var username : String = ""
var email : String = ""
override init(){
super.init();
}
func encode(with aCoder: NSCoder) {
aCoder.encode(self.userID, forKey: "id");
aCoder.encode(self.firstName, forKey: "first_name");
aCoder.encode(self.lastName, forKey: "last_name");
aCoder.encode(self.name, forKey: "name");
aCoder.encode(self.username,forKey: "username");
aCoder.encode(self.email, forKey: "email");
}
required init?(coder aDecoder: NSCoder) {
super.init()
self.userID = aDecoder.decodeInteger(forKey: "id");
self.firstName = aDecoder.decodeObject(forKey: "first_name") as! String;
self.lastName = aDecoder.decodeObject(forKey: "last_name") as! String;
self.name = aDecoder.decodeObject(forKey: "name") as! String
self.username = aDecoder.decodeObject(forKey: "username") as! String
self.email = aDecoder.decodeObject(forKey: "email") as! String;
}
init(data : [String: AnyObject]) {
super.init()
self.userID = String.numberValue(data["user_id"]).intValue;
self.firstName = String.stringValue(data["first_name"]);
self.lastName = String.stringValue(data["last_name"]);
self.email = String.stringValue(data["email"]);
self.username = String.stringValue(data["user_name"]);
}
class func loadLoggedInUser() -> User {
if let archivedObject = UserDefaults.standard.object(forKey:"CurrentUserAcc"){
if let user = NSKeyedUnarchiver.unarchiveObject(with: (archivedObject as! NSData) as Data) as? User {
return user;
}
}
return User()
}
func saveUser(){
let archivedObject : NSData = NSKeyedArchiver.archivedData(withRootObject: self) as NSData
UserDefaults.standard.set(archivedObject, forKey: "CurrentUserAcc");
UserDefaults.standard.synchronize();
}
func deleteUser(){
UserDefaults.standard.set(nil, forKey: "CurrentUserAcc")
UserDefaults.standard.synchronize();
}
}
I ran into an issue where I could not use a lazy variable inside init?(coder aDecoder: NSCoder)
My sample code is
class Category: NSObject, NSCoding {
var categoryID: NSInteger!
var categoryName: String!
var categoryLogoURL: String!
lazy var categoryTags = [String]()
private override init() {
}
required init?(coder aDecoder: NSCoder) {
self.categoryID = aDecoder.decodeInteger(forKey: "categoryID")
self.categoryName = aDecoder.decodeObject(forKey: "categoryName") as! String
self.categoryLogoURL = aDecoder.decodeObject(forKey: "categoryLogoURL") as! String
self.categoryTags = aDecoder.decodeObject(forKey: "categoryTags") as! [String]
}
func encode(with aCoder: NSCoder) {
aCoder.encode(self.categoryID, forKey: "categoryID")
aCoder.encode(categoryName, forKey: "categoryName")
aCoder.encode(categoryLogoURL, forKey: "categoryLogoURL")
aCoder.encode(categoryTags, forKey: "categoryTags")
}
}
I am getting an error Use of 'self' in property access 'categoryTags' before super.init initializes self
Once I remove lazy everything works fine. What I am doing wrong?
call Super Init:
required init?(coder aDecoder: NSCoder) {
super.init()
self.categoryID = aDecoder.decodeInteger(forKey: "categoryID")
self.categoryName = aDecoder.decodeObject(forKey: "categoryName") as! String
self.categoryLogoURL = aDecoder.decodeObject(forKey: "categoryLogoURL") as! String
self.categoryTags = aDecoder.decodeObject(forKey: "categoryTags") as! [String]
}
I am trying to use NSUserDefaults to save an array in to my app's core data. I thought it would be good to use NSUserDefaults but the problem is that wherever I put the code that creates the default it throws up the SIGABRT error.
Here is the code that creates the default:
let levelArrayDefault = NSUserDefaults.standardUserDefaults()
levelArrayDefault.setValue(levelsArray, forKey: "levelsArray")
levelArrayDefault.synchronize()
levelsArray is an array of List objects:
class List: NSObject, NSCoding {
// MARK: Properties
var name: String
var AnswersArray = [Answer]()
init?(name: String) {
// Initialize stored properties.
self.name = name
if name.isEmpty {
return nil
}
}
required init(coder decoder: NSCoder){
self.AnswersArray = (decoder.decodeObjectForKey("AA") as? [Answer])!
self.name = (decoder.decodeObjectForKey("name") as? String)!
}
func encodeWithCoder(coder: NSCoder) {
if let AnswersArray = AnswersArray { coder.encodeObject(AnswersArray, forKey: "AA") }
if let name = name { coder.encodeObject(name, forKey: "name") }
}
}
class Answer: NSObject, NSCoding {
var EnglishAnswer: String = ""
var ChineseAnswer: String = ""
init(newEng: String, newChi: String){
self.EnglishAnswer = newEng
self.ChineseAnswer = newChi
}
required init(coder decoder: NSCoder){
self.EnglishAnswer = (decoder.decodeObjectForKey("EnglishAnswer") as? String)!
self.ChineseAnswer = (decoder.decodeObjectForKey("ChineseAnswer") as? String)!
}
func encodeWithCoder(coder: NSCoder) {
if let EnglishAnswer = EnglishAnswer { coder.encodeObject(EnglishAnswer, forKey: "EnglishAnswer") }
if let ChineseAnswer = ChineseAnswer { coder.encodeObject(ChineseAnswer, forKey: "ChineseAnswer") }
}
}
How can I stop SIGABRT from popping up and get the array to be stored.
Help would be much appreciated.
You need to convert it to NSData using NSKeyedArchiver before storing it to NSUserDefaults, try like this:
update: Xcode 11.4 • Swift 5.2 or later
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let list = List(name: "Student")
list.answers = [Answer(english: "english answer", chinese: "中文回答")]
let data = (try? NSKeyedArchiver.archivedData(withRootObject: [list], requiringSecureCoding: false)) ?? Data()
UserDefaults.standard.set(data, forKey: "listData")
guard
let loadedData = UserDefaults.standard.data(forKey: "listData"),
let loadedArray = try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(loadedData) as? [List]
else { return }
print(loadedData.count)
print(loadedArray.first ?? "none")
print(loadedArray.first?.name ?? "no name")
print(loadedArray.first?.answers.first?.english ?? "no english")
print(loadedArray.first?.answers.first?.chinese ?? "no chinese")
}
}
class Answer: NSObject, NSCoding {
let english: String
let chinese: String
init(english: String, chinese: String) {
self.english = english
self.chinese = chinese
}
required init(coder decoder: NSCoder) {
self.english = decoder.decodeString(forKey: "english")
self.chinese = decoder.decodeString(forKey: "chinese")
}
func encode(with coder: NSCoder) {
coder.encode(english, forKey: "english")
coder.encode(chinese, forKey: "chinese")
}
}
class List: NSObject, NSCoding {
let name: String
fileprivate var data = Data()
var answers: [Answer] {
get {
(try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data)) as? [Answer] ?? []
}
set {
data = (try? NSKeyedArchiver.archivedData(withRootObject: newValue, requiringSecureCoding: false)) ?? Data()
}
}
init(name: String) {
self.name = name
}
required init(coder decoder: NSCoder) {
self.data = decoder.decodeData(forKey: "answersData")
self.name = decoder.decodeString(forKey: "name")
}
func encode(with coder: NSCoder) {
coder.encode(data, forKey: "answersData")
coder.encode(name, forKey: "name")
}
}
extension NSCoder {
func decodeString(forKey key: String) -> String {
return decodeObject(forKey: key) as? String ?? ""
}
func decodeData(forKey key: String) -> Data {
return decodeObject(forKey: key) as? Data ?? Data()
}
}
If you want to save your custom object in NSUserDefaults, it's not enough to make your class NSCoding-compliant -- you have to actually encode the data into an NSData object. This is a common mistake -- see my answer to another question for a similar situation.
So, you've added NSCoding to your Answer and List classes. That's a good start. Before you continue, you should verify that you've got that step right by using a NSKeyedArchiver to encode an example of a List object containing a few Answer objects into an instance of NSData, and then use NSKeyedUnarchiver to decode that data object back into your List. Verify that everything that you care about completes the round trip with no problems. This would be an excellent place to use Xcode's testing facility -- you could write a unit test that does exactly what I've described.
Once you know you've got the NSCoding stuff right, you should modify your code so that it encodes your List as NSData and stores the resulting data object in NSUserDefaults using the -setObject:forKey: method.
I am trying to use NSUserDefaults to save an array in to my app's core data. I thought it would be good to use NSUserDefaults but the problem is that wherever I put the code that creates the default it throws up the SIGABRT error.
Here is the code that creates the default:
let levelArrayDefault = NSUserDefaults.standardUserDefaults()
levelArrayDefault.setValue(levelsArray, forKey: "levelsArray")
levelArrayDefault.synchronize()
levelsArray is an array of List objects:
class List: NSObject, NSCoding {
// MARK: Properties
var name: String
var AnswersArray = [Answer]()
init?(name: String) {
// Initialize stored properties.
self.name = name
if name.isEmpty {
return nil
}
}
required init(coder decoder: NSCoder){
self.AnswersArray = (decoder.decodeObjectForKey("AA") as? [Answer])!
self.name = (decoder.decodeObjectForKey("name") as? String)!
}
func encodeWithCoder(coder: NSCoder) {
if let AnswersArray = AnswersArray { coder.encodeObject(AnswersArray, forKey: "AA") }
if let name = name { coder.encodeObject(name, forKey: "name") }
}
}
class Answer: NSObject, NSCoding {
var EnglishAnswer: String = ""
var ChineseAnswer: String = ""
init(newEng: String, newChi: String){
self.EnglishAnswer = newEng
self.ChineseAnswer = newChi
}
required init(coder decoder: NSCoder){
self.EnglishAnswer = (decoder.decodeObjectForKey("EnglishAnswer") as? String)!
self.ChineseAnswer = (decoder.decodeObjectForKey("ChineseAnswer") as? String)!
}
func encodeWithCoder(coder: NSCoder) {
if let EnglishAnswer = EnglishAnswer { coder.encodeObject(EnglishAnswer, forKey: "EnglishAnswer") }
if let ChineseAnswer = ChineseAnswer { coder.encodeObject(ChineseAnswer, forKey: "ChineseAnswer") }
}
}
How can I stop SIGABRT from popping up and get the array to be stored.
Help would be much appreciated.
You need to convert it to NSData using NSKeyedArchiver before storing it to NSUserDefaults, try like this:
update: Xcode 11.4 • Swift 5.2 or later
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let list = List(name: "Student")
list.answers = [Answer(english: "english answer", chinese: "中文回答")]
let data = (try? NSKeyedArchiver.archivedData(withRootObject: [list], requiringSecureCoding: false)) ?? Data()
UserDefaults.standard.set(data, forKey: "listData")
guard
let loadedData = UserDefaults.standard.data(forKey: "listData"),
let loadedArray = try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(loadedData) as? [List]
else { return }
print(loadedData.count)
print(loadedArray.first ?? "none")
print(loadedArray.first?.name ?? "no name")
print(loadedArray.first?.answers.first?.english ?? "no english")
print(loadedArray.first?.answers.first?.chinese ?? "no chinese")
}
}
class Answer: NSObject, NSCoding {
let english: String
let chinese: String
init(english: String, chinese: String) {
self.english = english
self.chinese = chinese
}
required init(coder decoder: NSCoder) {
self.english = decoder.decodeString(forKey: "english")
self.chinese = decoder.decodeString(forKey: "chinese")
}
func encode(with coder: NSCoder) {
coder.encode(english, forKey: "english")
coder.encode(chinese, forKey: "chinese")
}
}
class List: NSObject, NSCoding {
let name: String
fileprivate var data = Data()
var answers: [Answer] {
get {
(try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data)) as? [Answer] ?? []
}
set {
data = (try? NSKeyedArchiver.archivedData(withRootObject: newValue, requiringSecureCoding: false)) ?? Data()
}
}
init(name: String) {
self.name = name
}
required init(coder decoder: NSCoder) {
self.data = decoder.decodeData(forKey: "answersData")
self.name = decoder.decodeString(forKey: "name")
}
func encode(with coder: NSCoder) {
coder.encode(data, forKey: "answersData")
coder.encode(name, forKey: "name")
}
}
extension NSCoder {
func decodeString(forKey key: String) -> String {
return decodeObject(forKey: key) as? String ?? ""
}
func decodeData(forKey key: String) -> Data {
return decodeObject(forKey: key) as? Data ?? Data()
}
}
If you want to save your custom object in NSUserDefaults, it's not enough to make your class NSCoding-compliant -- you have to actually encode the data into an NSData object. This is a common mistake -- see my answer to another question for a similar situation.
So, you've added NSCoding to your Answer and List classes. That's a good start. Before you continue, you should verify that you've got that step right by using a NSKeyedArchiver to encode an example of a List object containing a few Answer objects into an instance of NSData, and then use NSKeyedUnarchiver to decode that data object back into your List. Verify that everything that you care about completes the round trip with no problems. This would be an excellent place to use Xcode's testing facility -- you could write a unit test that does exactly what I've described.
Once you know you've got the NSCoding stuff right, you should modify your code so that it encodes your List as NSData and stores the resulting data object in NSUserDefaults using the -setObject:forKey: method.