I have this class that have to be the subclass of OIDAuthState (this class is an NSObject and conforms to NSSecureCoding),
The code to encode the class OIDAuthState was working fine before
self.data = try NSKeyedArchiver.archivedData(withRootObject: authState, requiringSecureCoding: true)
Once I created this subclass that includes adds a simple Boolean to the class isExpiredTokenEnforced, I now get the error when using NSKeyedArchiver,
The error says:
NSDebugDescription=Caught exception during archival: *** -decodeBoolForKey: only defined for abstract class. Define -[NSKeyedArchiver decodeBoolForKey:]!
Here is the subclass I am trying to archive and down below the override method to encode and decode this class, I am simply encoding and decoding this 1 extra property and then passing down the coder to the parent class,
class AuthenticationStateManager: OIDAuthState, AuthenticationState {
var isExpiredTokenEnforced = false
var lastTokenResponseInterface: TokenResponse? {
if isExpiredTokenEnforced {
return EnforcedExpiredTokenResponse(idToken: super.lastTokenResponse?.idToken,
accessToken: super.lastTokenResponse?.accessToken)
} else {
return super.lastTokenResponse
}
}
override static var supportsSecureCoding: Bool { true }
required override init(authorizationResponse: OIDAuthorizationResponse?, tokenResponse: OIDTokenResponse?, registrationResponse: OIDRegistrationResponse?) {
super.init(authorizationResponse: authorizationResponse, tokenResponse: tokenResponse, registrationResponse: registrationResponse)
}
required init?(coder: NSCoder) {
coder.encode(isExpiredTokenEnforced, forKey: "isExpiredTokenEnforced")
super.init(coder: coder)
}
override func encode(with coder: NSCoder) {
self.isExpiredTokenEnforced = coder.decodeBool(forKey: "isExpiredTokenEnforced")
super.encode(with: coder)
}
}
I can't figure out why this is failing I couldn't find relevant information to fix this,
does anyone have a clue what could be wrong here?
Thank you in advance for your time.
You are mixing up your encoder and decoder functions. Your func encode() is trying to call decodeBool. It should be calling encode().
Similarly your init?(coder:) function should be calling decode (or rather decodeBool(forKey:).)
Related
I want to serialize and deserialize an object of my GKGraphNode subclass using NSKeyedArchiver and NSKeyedUnarchiver. So I try the following:
//: Playground - noun: a place where people can play
import GameplayKit
class MyGraphNode: GKGraphNode {
static let textCodingKey = "TextCodingKey"
let text: String
override convenience init() {
self.init(text: "Default Text")
}
init(text: String) {
self.text = text
super.init()
}
required init?(coder aDecoder: NSCoder) {
text = aDecoder.decodeObject(forKey: MyGraphNode.textCodingKey) as! String
super.init(coder: aDecoder)
}
override func encode(with aCoder: NSCoder) {
super.encode(with: aCoder)
aCoder.encode(text, forKey: MyGraphNode.textCodingKey)
}
}
let text = "Test Text"
let graphNode = MyGraphNode(text: text)
let data = NSKeyedArchiver.archivedData(withRootObject: graphNode)
if let unarchivedGraphNode = NSKeyedUnarchiver.unarchiveObject(with: data) as? MyGraphNode {
print("Text: \(unarchivedGraphNode.text)")
}
Unfortunately the example prints only the default text and not the expected test text:
Text: Default Text
First I omitted the convenience initializer. But in this case it crashed with this error:
error: Execution was interrupted, reason: EXC_BAD_INSTRUCTION
(code=EXC_I386_INVOP, subcode=0x0). The process has been left at the
point where it was interrupted, use "thread return -x" to return to
the state before expression evaluation.
GKGraphNodeSubclass.playground: 5: 7: Fatal error: Use of
unimplemented initializer 'init()' for class
'__lldb_expr_58.MyGraphNode'
Can anyone explain why the test text is ignored during the deserialization?
Or why I have to add the convenience initializer at all?
I got help in the Apple Developer Forum:
The "text" property is ending up being reset by "super.init(coder: aDecoder)", presumably because that calls "init()" internally, and that ends up at your convenience "init ()". This would be illegal in Swift, but it's legal in Obj-C, which doesn't have the same strict initialization rules.
The solution is to initialize "text" after the super.init(coder:), rather than before. This means you can't use a "let" property
To fix my example I changed the variable declaration and the NSCoding initializer like this:
var text: String!
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
text = aDecoder.decodeObject(forKey: MyGraphNode.textCodingKey) as! String
}
I agree with Ruben, with a small addition
It might also be necessary to override the init() to ensure it exist. Due to the strict initialization rules of Swift
override init() {
super.init()
}
serialization and deserialization is done by the two method defined in the NSCoding protocol as follow
encodeWithCoder(_ aCoder: NSCoder) {
// Serialize your object here
}
init(coder aDecoder: NSCoder) {
// Deserialize your object here
}
In my own ViewController (inherited from UITableViewController), I have a Array which contain my own object named Item and I do implemented the init(coder aDecoder: NSCoder) initial function. The Item is defined as follow
class Item: NSObject, NSCoding {
var text = ""
var checked = false
func toggleChecked() {
checked = !checked
}
func encode(with aCoder: NSCoder) {
aCoder.encode(self.text, forKey: "SLAText")
aCoder.encode(self.checked, forKey: "SLAChecked")
}
required init?(coder aDecoder: NSCoder) {
self.text = aDecoder.decodeObject(forKey: "SLAText") as! String
self.checked = aDecoder.decodeBool(forKey: "SLAChecked")
super.init()
}
override init() {
super.init()
}
}
Instead implement the function encode(with: NSCoder) I defined my own serialization function named saveItems()
func saveItems() {
let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWith: data)
archiver.encode(items, forKey: "ItemLists") //items is a array of type [Item]
archiver.finishEncoding()
data.write(to: dataFilePath(), atomically: true)
}
Question
Why the code is working with out implement the required NSCoding function? The code is simplified from a example of the book I'm studying, I didn't find the encodeWithCoder(_ aCoder: NSCoder) function at all. Isn't the required means you have to implemented it?
Thanks for your time and help
Why the code is working with out implement the required NSCoding function?
This is not true.
NSCoding is a protocol
First of all NSCoding is a protocol, not a function. And in order to conform a type to NSCoding you need to implement a method and an initializer
public func encode(with aCoder: NSCoder)
public init?(coder aDecoder: NSCoder)
Why does your code work?
Let's look at what you are doing
archiver.encode(items, forKey: "ItemLists")
Here items is defined as [Item] which is and array of Item(s).
And Array does conform to NSCoding. This can be easily tested by writing
let nums = [1, 2, 3]
if nums is NSCoding {
print("Array does conform to NSCoding")
} else {
print("Array does NOT conform to NSCoding")
}
The result is
Array does conform to NSCoding
Conclusion
Of course to work properly the element inside of the array must be conform to NSCodable too. And since the generic type of your Array is Item (which you made conform to NSCodable) the mechanism does work properly.
Trying to refactor my code in order to avoid having to reference shared instances all over the place, rather I'd like to inject them via a custom initializer. My limited understanding of initilazation in Swift is preventing me to do so.
Here's my ViewController, minus the methods and boilerplate:
class LoginVC: UIViewController {
let dataManager: DataManager
let restManager: RestManager
let defaults: UserDefaults
init(defaults: UserDefaults = .standard, dataManager: DataManager = .sharedInstance, restManager: RestManager = .sharedInstance) {
self.defaults = defaults
self.dataManager = dataManager
self.restManager = restManager
super.init(nibName: nil, bundle: nil)
}
}
I've provided default values which are shared instances declared as a static constant in their respective singleton classes of DataManager and RestManager. Was planning to do this in each and every ViewController that has these singletons referenced in them. Anyways, my problem arises as the compiler complains that I must provide a required initializer init(coder: aDecoder).
No problem, but after implementing...
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
... the compiler once again complains, this time that
Blockquote Property 'self.defaults' not initialized at super.init call
Which I guess makes sense since the required init? is, as far as I know, a delegating init (could be that I'm totally mistaken here). I do not know how to pass the default params of my custom init to the super init of this initializer, or if that's even possible.
I have tried a workaround though by changing the constants to mutable variables and by making them implicitly unwrapped like so:
class LoginVC: UIViewController {
var dataManager: DataManager!
var restManager: RestManager!
var defaults: UserDefaults!
init(defaults: UserDefaults = .standard, dataManager: DataManager = .sharedInstance, restManager: RestManager = .sharedInstance) {
self.defaults = defaults
self.dataManager = dataManager
self.restManager = restManager
super.init(nibName: nil, bundle: nil)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
This workaround actually manages to compile and build, but the app crashes as soon as userDefaults which are in viewDidLoad are unwrapped because they have a nil value. All of them have nil values even though they are defaulted in the params of the custom initializer which leads me to believe that I've royally screwed up.
Any help/clarification would be greatly appreciated, thanks in advance.
Not sure that this is what you would like to do, but I would suggest you this solution
extension UIViewController {
var defaults: UserDefaults {
get {
return .standard
}
}
}
and so in each UIViewController you can do self.defaults
If you want some of your UIViewControllers to have another references, you can do this
//create protocol with all vars
protocol References {
var defaults: UserDefaults {get}
}
//create extension with default implementation
extension References {
var defaults: UserDefaults {
get {
return .standard
}
}
}
//add this protocol to all UIViewControllers
extension UIViewController: References {
}
//or create new class with references
class ReferenceViewController: UIViewController, References {
}
//override reference in some view controller if needed
class AnotherReferencesViewController: UIViewController { //or ReferenceViewController
var defaults: UserDefaults {
get {
//something new
return .standard
}
}
}
i'm newbie in swift adn i have problem with initwithcoder in swift.
I have class UserItem, i need it to save user login.
in objective c is like this
- (id)initWithCoder:(NSCoder *)decoder{
if (self = [super init]){
self.username = [decoder decodeObjectForKey:#"username"];
}
return self;
}
and in swift i'm trying like this
override init() {
super.init()
}
required init(coder decoder: NSCoder!) {
self.username = (decoder.decodeObjectForKey("username")?.stringValue)!
super.init(coder: decoder)
}
but if like above, i get error on code
super.init(coder: decoder)
error message is "extra argument 'coder' in call
i can't figure out anymore, so i'm try this code,
convenience init(decoder: NSCoder) {
self.init()
self.username = (decoder.decodeObjectForKey("username")?.stringValue)!
}
but, get error
.UserItem initWithCoder:]: unrecognized selector sent to instance 0x7fd4714ce010
what should i do? thanks before for your help.
I struggled with NSCoding (the protocol that you use to archive and unarchive objects) in the past and I'm seeing that you are going through the same pains. Hope this lessen it a bit:
class UserItem: NSObject, NSCoding {
var username: String
var anInt: Int
init(username: String, anInt: Int) {
self.username = username
self.anInt = anInt
}
required init?(coder aDecoder: NSCoder) {
// super.init(coder:) is optional, see notes below
self.username = aDecoder.decodeObjectForKey("username") as! String
self.anInt = aDecoder.decodeIntegerForKey("anInt")
}
func encodeWithCoder(aCoder: NSCoder) {
// super.encodeWithCoder(aCoder) is optional, see notes below
aCoder.encodeObject(self.username, forKey: "username")
aCoder.encodeInteger(self.anInt, forKey: "anInt")
}
// Provide some debug info
override var description: String {
get {
return ("\(self.username), \(self.anInt)")
}
}
}
// Original object
let a = UserItem(username: "michael", anInt: 42)
// Serialized data
let data = NSKeyedArchiver.archivedDataWithRootObject(a)
// Unarchived from data
let b = NSKeyedUnarchiver.unarchiveObjectWithData(data)!
print(a)
print(b)
The important thing is to match up the keys and the data types in encodeWithCoder(aCoder:) (the archive function) and init(coder:) (the unarchive function).
Where is confusing for beginners is what to do with the superclass. You should only include the superclass in the two functions above if the superclass itself conforms to NSCoding. NSObject does not provide that by itself. The idea is each class knows about its own properties, some of which are private. If the superclass cannot archive/unarchive, there's no need to call them.
I'm attempting to create a custom NSTextFieldCell subclass in Swift (Xcode Beta 5), with the following code:
class CustomHighlightTextFieldCell : NSTextFieldCell {
required init(coder aCoder: NSCoder!) {
super.init(coder: aCoder)
}
init(imageCell anImage: NSImage!) {
super.init(imageCell: anImage)
}
init(textCell aString: String!) {
super.init(textCell: aString)
}
}
However, I receive compilation errors on the 2nd and 3rd init() declarations:
/Users/Craig/projects/.../CustomHighlightTextFieldCell:8:40: Invalid redeclaration of 'init(imageCell:)'
/Users/Craig/projects/.../CustomHighlightTextFieldCell.swift:17:5: 'init(imageCell:)' previously declared here
/Users/Craig/projects/.../CustomHighlightTextFieldCell:7:39: Invalid redeclaration of 'init(textCell:)'
/Users/Craig/projects/.../CustomHighlightTextFieldCell.swift:21:5: 'init(textCell:)' previously declared here
While there are some strange compiler bugs here (I'm getting the usual "SourceKitService Terminated, Editor functionality temporarily limited." message), it seems like I'm missing something in my method overriding - but I can't tell what.
I was under the assumption the named parameters, or at least the parameter types, would indicate that there are three different init() methods here, but apparently I'm missing a key piece of the puzzle.
Edit: If I add override to the 2nd and 3rd init() methods, I have a separate issue:
required init(coder aCoder: NSCoder!) {
super.init(coder: aCoder)
}
override init(imageCell anImage: NSImage!) {
super.init(imageCell: anImage)
}
override init(textCell aString: String!) {
super.init(textCell: aString)
}
This new issue (simply invoked by adding the two override keywords) seems to almost contradict the original.
/Users/Craig/projects/.../CustomHighlightTextFieldCell.swift:17:14: Initializer does not override a designated initializer from its superclass
/Users/Craig/projects/.../CustomHighlightTextFieldCell.swift:21:14: Initializer does not override a designated initializer from its superclass
It would seem that your declarations (with override) should be sufficient, however, they seem to need the #objc declarations as well. This works:
class CustomHighlightTextFieldCell : NSTextFieldCell {
required init(coder aCoder: NSCoder!) {
super.init(coder: aCoder)
}
#objc(initImageCell:)
override init(imageCell anImage: NSImage!) {
super.init(imageCell: anImage)
}
#objc(initTextCell:)
override init(textCell aString: String!) {
super.init(textCell: aString)
}
}
As you see, you have the corresponding super.init(xxx) in the functions which means you are overriding the functions. So just add the override keyword.
override init(imageCell anImage: NSImage!) {
super.init(imageCell: anImage)
}
override init(textCell aString: String!) {
super.init(textCell: aString)
}