After I fill out my form I input everything in a NSDictionary.
All of my other items can save no problem if I comment this out.
One of them being category. I encode it but keep getting the error
encodeWithCoder:]: unrecognized selector sent to instance 0x1c80bbe40'
Category Items is a subclass of Codeable.
Saving.
let playerDict : NSDictionary = [
"category" : CategoryItems(name: categoryData[0].name, image: categoryData[0].image, type: categoryData[0].type),
]
class PlayerModel: NSObject, NSCoding {
var category: CategoryItems?
init(json: NSDictionary) {
if let category = json["category"] as? CategoryItems {
self.category = category
}
}
}
required init?(coder aDecoder: NSCoder) {
if let category = aDecoder.decodeObject(forKey: "category") as? CategoryItems {
self.category = category
}
}
func encode(with aCoder: NSCoder) {
if let category = self.category {
aCoder.encode(category, forKey: "category")
}
}
Model:
struct CategoryItems: Codable {
var name : String
var image : String
var type : playerType
}
The main issue is that you can't use NSCoding with structs. Objects adopting NSCoding must be a subclass of NSObject.
I recommend to drop NSCoding completely and use Codable also for the class. Maybe you can resign the NSObject inheritance or even being a class.
Related
Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 5 years ago.
Improve this question
In a UITableView when deleting a row and saving the data source I also want to save to persistent storage.
I'm using NSKeyedArchiver to save an array of my custom object type Participant and it fails straight away with:
2018-02-13 23:01:41.818945+0000 ProjectName[28680:5720571]
-[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance 0x60800004d290
2018-02-13 23:01:41.826553+0000 ProjectName[28680:5720571] *** Terminating app due to uncaught
exception 'NSInvalidArgumentException', reason: '-[_SwiftValue
encodeWithCoder:]: unrecognized selector sent to instance
0x60800004d290'
I've searched everywhere and can't find anything that's applicable to me. So far as I can tell my data class for Participant object conforms to NSObject and NSCoding with the necessary methods implemented.
EDIT: Thank you all for your feedback so quickly. Code is below and as I said before, if I've neglected to post something necessary that likely speaks to my experience so any help gratefully received!
Data Class (excerpt)
class Participant: NSObject, NSCoding {
//MARK: Properties
var name: String
var jobTitle: String?
var picture: UIImage?
var rate: Float
var ratePeriod: ratePeriods
//MARK: Archiving Paths
static let DocumentsDirectory = FileManager().urls(for: .documentDirectory, in: .userDomainMask).first!
static let ArchiveURL = DocumentsDirectory.appendingPathComponent("participants")
//MARK: Types
struct PropertyKey {
//THESE MUST NOT CHANGE ONCE BUILT
static let name = "name"
static let jobTitle = "jobTitle"
static let picture = "picture"
static let rate = "rate"
static let ratePeriod = "ratePeriod"
}
//MARK: Initialisation
init?(name: String, jobTitle: String?, picture: UIImage?, rate: Float?, ratePeriod: ratePeriods?) {
//The name must not be empty
guard !name.isEmpty else {
return nil
}
//Init stored properties
self.name = name
self.jobTitle = jobTitle ?? ""
self.picture = picture
self.rate = rate ?? 0.0
self.ratePeriod = ratePeriod ?? .annually
}
//MARK: NSCoding
func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: PropertyKey.name)
aCoder.encode(jobTitle, forKey: PropertyKey.jobTitle)
aCoder.encode(picture, forKey: PropertyKey.picture)
aCoder.encode(rate, forKey: PropertyKey.rate)
aCoder.encode(ratePeriod, forKey: PropertyKey.ratePeriod)
}
required convenience init?(coder aDecoder: NSCoder) {
//The name is required. If we cannot decode a name string, the init should fail.
guard let name = aDecoder.decodeObject(forKey: PropertyKey.name) as? String else {
return nil
}
let jobTitle = aDecoder.decodeObject(forKey: PropertyKey.jobTitle) as? String
let picture = aDecoder.decodeObject(forKey: PropertyKey.picture) as? UIImage
let rate = aDecoder.decodeFloat(forKey: PropertyKey.rate)
let ratePeriod = aDecoder.decodeObject(forKey: PropertyKey.ratePeriod) as? ratePeriods
//Must call designated init
self.init(name: name, jobTitle: jobTitle, picture: picture, rate: rate, ratePeriod: ratePeriod)
}
}
From inside Private Func where I'm trying to make use of it and it breaks
let archivePath = Participant.ArchiveURL.path
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(participants, toFile: archivePath)
Thank you again for any help I can get on this.
EDIT 2: I've done a bit more debugging and I guess my inexperience with the Xcode IDE and debugging has hindered this but it looks to be the ratePeriod property of the object being stored that's throwing the error. This property is a Struct which I think somebody else leaned to as being an issue. Is this resolvable or do I need to look at a different method for persisting storage of Structs?
EDIT 3: I've solved the problem but don't know how to mark this as resolved. The issue wasn't the Struct (which I wasn't storing) but rather an Enum. When using NSKeyedArchiver and NSCoding to store Enums you need to store the .rawValue and reconstitute it as an Int. ie: -
Encoding
aCoder.encode(ratePeriod.rawValue, forKey: PropertyKey.ratePeriod)
and
Decoding
let ratePeriodIntValue = (aDecoder.decodeObject(forKey: PropertyKey.ratePeriod) as? Int) ?? ratePeriods.annually.rawValue
let ratePeriod = ratePeriods(rawValue: ratePeriodIntValue)
Your custom object type, Participant, needs to be a class (not a struct), and in particular it must be a subclass of NSObject. Now you can adopt NSCoding successfully.
There is a very simple article on NSHipster about how to make your custom classes NSCoding/NSKeyedArchiver compliant. I recommend giving that a look.
As a basic answer, in order to make your object work with NSKeyedArchiver you need to tell the coder/decoder how to encode/decode your object. For example, if this is your class:
class Participant {
let name: String
let id: String
let age: Int
init(name: String, id: String, age: Int) {
self.name = name
self.id = id
self.age = age
}
}
You would need to make the following modifications to make it work with NSKeyedArchiver. First, declare that you are conforming to NSObject and NSCoding protocols. Then implement the encode methods and the convenience init?(coder:_) initializer:
class Participant: NSObject, NSCoding {
let name: String
let id: String
let age: Int
init(name: String, id: String, age: Int) {
self.name = name
self.id = id
self.age = age
}
required convenience init?(coder aDecoder: NSCoder) {
guard let name = aDecoder.decodeObject(forKey: "name") as? String,
let id = aDecoder.decodeObject(forKey: "id") as? String,
let age = aDecoder.decodeObject(forKey: "age") as? Int else { return nil }
self.init(name: name, id: id, age: age)
}
func encode(with aCoder: NSCoder) {
aCoder.encode(self.name, forKey: "name")
aCoder.encode(self.id, forKey: "id")
aCoder.encode(self.age, forKey: "age")
}
}
Try adding #objc to your swift equivalent encodeWithCoder: method. Ditto for the decode init method. I doubt it's the solution but might be.
Also, please show how you wrote the NSCoding methods in Swift. Maybe they don't match up, given the inherent conversion between Swift and ObjC for how they are to be written?
func encode(with aCoder: NSCoder) {
Im learning about NSUserDefaults and I have a class that instantiates a person with a first and last name.
class Person: NSObject, NSCoding {
var firstName: String!
var lastName: String!
init(first:String, last:String) {
firstName = first
lastName = last
}
override init() {
}
required convenience init?(coder aDecoder: NSCoder) {
self.init()
self.firstName = aDecoder.decodeObjectForKey("firstName") as? String
self.lastName = aDecoder.decodeObjectForKey("lastName") as? String
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(self.firstName, forKey: "firstName")
aCoder.encodeObject(self.lastName, forKey: "lastName")
}
}
I am wondering why I have to override my first initializer that has initializes first and last names with an empty initializer?
Also, what exactly is a "required convenience" initializer?
Thank you
You need to call NSObject's initializer in your custom initializer:
init(first:String, last:String) {
firstName = first
lastName = last
super.init()
}
I have got a class that inherits from NSObject and I want it to be NSCoding compliant. But I ran into trouble while encoding an array of objects which should implement a protocol.
protocol MyProtocol {
var myDescription: String { get }
}
class DummyClass: NSObject, NSCopying, MyProtocol {
var myDescription: String {
return "Some description"
}
func encodeWithCoder(aCoder: NSCoder) {
// does not need to do anything since myDescription is a computed property
}
override init() { super.init() }
required init?(coder aDecoder: NSCoder) { super.init() }
}
class MyClass: NSObject, NSCoding {
let myCollection: [MyProtocol]
init(myCollection: [MyProtocol]) {
self.myCollection = myCollection
super.init()
}
required convenience init?(coder aDecoder: NSCoder) {
let collection = aDecoder.decodeObjectForKey("collection") as! [MyProtocol]
self.init(myCollection: collection)
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(myCollection, forKey: "collection")
}
}
For aCoder.encodeObject(myCollection, forKey: "collection") I get the error:
Cannot convert value of type '[MyProtocol]' to expected argument type 'AnyObject?'
OK, a protocol obviously is not an instance of a class and so it isn't AnyObject? but I've no idea how to fix that. Probably there is a trick that I'm not aware? Or do you do archiving/serialization differently in Swift as in Objective-C?
There's probably a problem with let collection = aDecoder.decodeObjectForKey("collection") as! [MyProtocol], too but the compiler doesn't complain yet…
I've just found the solution myself: The key is to map myCollection into [AnyObject] and vice-versa, like so:
class MyClass: NSObject, NSCoding {
let myCollection: [MyProtocol]
init(myCollection: [MyProtocol]) {
self.myCollection = myCollection
super.init()
}
required convenience init?(coder aDecoder: NSCoder) {
let collection1 = aDecoder.decodeObjectForKey("collection") as! [AnyObject]
let collection2: [MyProtocol] = collection1.map { $0 as! MyProtocol }
self.init(myCollection: collection2)
}
func encodeWithCoder(aCoder: NSCoder) {
let aCollection: [AnyObject] = myCollection.map { $0 as! AnyObject }
aCoder.encodeObject(aCollection, forKey: "collection")
}
}
I know your title specifies Swift 2, but just for reference, for a similar problem I was working on, I found that in Swift 3, you don't need to convert anymore to AnyObject.
The following works for me in Swift 3 (using your example):
class MyClass: NSObject, NSCoding {
let myCollection: [MyProtocol]
init(myCollection: [MyProtocol]) {
self.myCollection = myCollection
super.init()
}
required convenience init?(coder aDecoder: NSCoder) {
let collection = aDecoder.decodeObject(forKey: "collection") as! [MyProtocol]
self.init(myCollection: collection)
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encode(aCollection, forKey: "collection")
}
}
I have a small app that has a few saving functionalities. I have a data model class called: Closet:
class Department: NSObject, NSCoding {
var deptName = ""
var managerName = ""
var Task: [Assignment]? // <----- assignment class is in example 2
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(deptName, forKey: "deptName")
aCoder.encodeObject(managerName, forKey: "mngName")
// aCoder.encodeObject(Task, forKey: "taskArray")
}
required init(coder aDecoder: NSCoder) {
super.init()
course = aDecoder.decodeObjectForKey("deptName") as! String
instructor = aDecoder.decodeObjectForKey("mngName") as! String
// Task = aDecoder.decodeObjectForKey("tasKArray") as? [Assignment]
}
override init() {
super.init()
}
}
So this is the main controller data model which in the first View Controller, a user is able to tap the "+" button to add a department name and manager name. The problem is not with saving this as i save it successfully using NSKeyedArchive and loads it back when the app starts.
The Problem:
I want to add an array of assignments on this data model Department called Assignment which would have a title and a notes variable. This is the Data model for Assignment:
Assignment.swift
class Assignment: NSObject, NSCoding {
var title = ""
var notes = ""
func encodeWithCoder(aCoder: NSCoder) {
// Methods
aCoder.encodeObject(title, forKey: "Title")
aCoder.encodeObject(notes, forKey: "notepad")
}
required init(coder aDecoder: NSCoder) {
// Methods
title = aDecoder.decodeObjectForKey("Title") as! String
notes = aDecoder.decodeObjectForKey("notepad") as! String
super.init()
}
override init() {
super.init()
}
}
So what i am essentially trying to achieve is an app where a user enters different departments with different manager names which work now in my app, but within a department, the user can click the "+" button to add an assignment title and notes section that can be editable when clicked which i can handle afterwards. These assignments are different from department to department.
My big problem is achieving this functionality. I can't seem to get this working.
I want this array assigment property to be part of the Department Class so each cell can have their own sort of To-Do list. any help would definitely help me out a lot. Thanks :)
You are using NSCoder correctly, but there are two errors in capitalization. The first error affects the functionality of the application, and the second error is a stylistic mistake. You encoded Task with the key "taskArray", but you tried to decode it with the key "tasKArray". If you fix the capital K in the latter, then your code will work.
The second capitalization error is a stylistic mistake: Task, like all properties in Swift, should be written in lowerCamelCase (llamaCase).
Be sure to pay close attention to indentation. In programming, there are special indentation rules we follow that help make code clear. Here is the corrected code with proper capitalization and indentation:
class Department: NSObject, NSCoding {
var deptName = ""
var managerName = ""
var task: [Assignment]?
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(deptName, forKey: "deptName")
aCoder.encodeObject(managerName, forKey: "mngName")
aCoder.encodeObject(task, forKey: "taskArray")
}
required init(coder aDecoder: NSCoder) {
super.init()
course = aDecoder.decodeObjectForKey("deptName") as! String
instructor = aDecoder.decodeObjectForKey("mngName") as! String
task = aDecoder.decodeObjectForKey("taskArray") as? [Assignment]
}
override init() {
super.init()
}
}
class Assignment: NSObject, NSCoding {
var title = ""
var notes = ""
func encodeWithCoder(aCoder: NSCoder) {
// Methods
aCoder.encodeObject(title, forKey: "Title")
aCoder.encodeObject(notes, forKey: "notepad")
}
required init(coder aDecoder: NSCoder) {
// Methods
title = aDecoder.decodeObjectForKey("Title") as! String
notes = aDecoder.decodeObjectForKey("notepad") as! String
super.init()
}
override init() {
super.init()
}
}
Updated for Swift 5 / Xcode Version 12.4 (12D4e)
Thanks for the example above Tone416 -- I've reworked it for Swift 5 as the protocols and methods have changed. I've also included a simple test to prove it out so you should be able to just cut and paste this into a playground a run it.
import Foundation
class Department: NSObject, NSCoding {
var deptName = ""
var managerName = ""
var task: [Assignment]?
func encode(with coder: NSCoder) {
coder.encode(deptName, forKey: "deptName")
coder.encode(managerName, forKey: "mngName")
coder.encode(task, forKey: "taskArray")
}
required init(coder aDecoder: NSCoder) {
super.init()
deptName = aDecoder.decodeObject(forKey: "deptName") as! String
managerName = aDecoder.decodeObject(forKey: "mngName") as! String
task = aDecoder.decodeObject(forKey: "taskArray") as? [Assignment]
}
override init() {
super.init()
}
convenience init(deptName: String, managerName: String, task: [Assignment]?) {
self.init()
self.deptName = deptName
self.managerName = managerName
self.task = task
}
}
class Assignment: NSObject, NSCoding {
var title = ""
var notes = ""
func encode(with coder: NSCoder) {
// Methods
coder.encode(title, forKey: "Title")
coder.encode(notes, forKey: "notepad")
}
required init(coder aDecoder: NSCoder) {
// Methods
title = aDecoder.decodeObject(forKey: "Title") as! String
notes = aDecoder.decodeObject(forKey: "notepad") as! String
super.init()
}
override init() {
super.init()
}
convenience init(title: String, notes: String) {
self.init()
self.title = title
self.notes = notes
}
}
// Create some data for testing
let assignment1 = Assignment(title: "title 1", notes: "notes 1")
let assignment2 = Assignment(title: "title 2", notes: "notes 2")
let myDepartment = Department(deptName: "My Dept", managerName: "My Manager", task: [assignment1, assignment2])
// Try archive and unarchive
do {
// Archive
let data = try NSKeyedArchiver.archivedData(withRootObject: myDepartment, requiringSecureCoding: false)
print ("Bytes in archive: \(data.count)")
// Unarchive
let obj = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as! Department
// Print the contents of the unarchived object
print("Department: \(obj.deptName) Manager: \(obj.managerName)")
if let task = obj.task {
for i in 0...task.count-1 {
print("Task: \(task[i].title) \(task[i].notes)")
}
}
} catch {
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
Enjoy
I try to store Array of objects in NSUserDefaults.
I have following snippets of code:
var accounts = MyAccounts()
var array:Array<MyAccounts.MyCalendar> = accounts.populateFromCalendars()
NSUserDefaults.standardUserDefaults().
setObject(array, forKey: "test_storeAccounts_array") // <- get error here
NSUserDefaults.standardUserDefaults().synchronize()
But I get Exception:
does not implement methodSignatureForSelector: -- trouble ahead
my class structure:
class MyAccounts {
/* ... */
class MyCalendar {
var title:String?
var identifier:String?
var email:String?
var calType:String?
var isActive:Bool?
var isMainAcount:Bool?
init(){}
}
}
Any ideas?
Make sure your class inherits from NSObject
class MyAccounts:NSObject {
/* ... */
class MyCalendar {
var title:String?
var identifier:String?
var email:String?
var calType:String?
var isActive:Bool?
var isMainAcount:Bool?
init(){}
}
}
I was getting this exception in Swift 3.0. In my case, my model class was not inherit from NSObject base class. just inherit my class from NSObject base class and implements NSCoding protocol (if your container array has custom objects)
class Stock: NSObject, NSCoding {
var stockName: String?
override init() {
}
//MARK: NSCoding protocol methods
func encode(with aCoder: NSCoder){
aCoder.encode(self.stockName, forKey: "name")
}
required init(coder decoder: NSCoder) {
if let name = decoder.decodeObject(forKey: "name") as? String{
self.stockName = name
}
}
func getStockDataFromDict(stockDict stockDict:[String:AnyObject]) -> Stock {
if let stockName = stockDict["name"] {
self.stockName = stockName as? String
}
return self
}
}
In Swift 2, I experienced similar error while using the Notification Pattern within a custom class. Note that when the same notification(Observe) is implemented in a ViewController class , it doesn't complain. Its only with the custom class, created from a Swift file without subclassing this error was thrown
class myClass : NSObject {
override init(){
super.init()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("functionCall:"), name: "NotificationName", object: nil)
}
//Implement function
func functionCall(notification: NSNotification) {
//Extract the object and implement the function
}
}
You need to convert the class into NSData first. Something like this:
var data = NSKeyedArchiver.archivedDataWithRootObject(accounts.populateFromCalendars())
var userDefaults = NSUserDefaults.standardUserDefaults();
userDefaults.setObject(data, forKey: "test_storeAccounts_array");