Need help getting NSSecureUnarchiveFromDataTransformer to work

Question

I am trying to implement NSSecureCoding but am getting some problems my code is this. a class called WrapperClass:

public class WrapperClass:NSObject, NSCoding, NSSecureCoding {
    public static var supportsSecureCoding: Bool = true
    
    var attributedStrings = [TextDocumentClass]()
    
    init(pAttributedStrings:[TextDocumentClass]) {
        self.attributedStrings = pAttributedStrings
    }
    
    required public init?(coder aDecoder: NSCoder){
        self.attributedStrings = aDecoder.decodeObject(of: [TextDocumentClass.self], forKey: "attributedStrings") as? [TextDocumentClass]
        
        //return self
    }
    
    public func encode(with aCoder: NSCoder) {
        aCoder.encode(attributedStrings,forKey:"attributedStrings")
    }
}

when this code get run i get nil instead of array of TextDocumentClass and i don't now why, i have tried using the following classes in aDecoder.decodeObject ([TextDocumentClass.self], NSArray.self and TextDocumentClass.self] but they all give the same I have made my own ValueTransformer because i need to support some classes that i don't think is included with the default for NSSecureUnarchiveFromDataTransformer

@objc(MyTestClassValueTransformer)
final class MyClassValueTransformer: NSSecureUnarchiveFromDataTransformer {

    static let name = NSValueTransformerName(rawValue: String(describing: MyClassValueTransformer.self))
    
    public static func register() {
        let transformer = MyClassValueTransformer()
        ValueTransformer.setValueTransformer(transformer, forName: name)
    }
    
    override static var allowedTopLevelClasses: [AnyClass] {
        return super.allowedTopLevelClasses + [WrapperClass.self, UIFont.self, NSObject.self, NSParagraphStyle.self]
    }
    
    override public class func transformedValueClass() -> AnyClass {
            return WrapperClass.self
        }

        override public class func allowsReverseTransformation() -> Bool {
            return true
        }
    
    override public func transformedValue(_ value: Any?) -> Any? {
        guard let data = value as? Data else {
            return nil
        }

        do {
            let box = try NSKeyedUnarchiver.unarchivedObject(
                ofClass: WrapperClass.self,
                from: data
            )
            return box
        } catch {
            return nil
        }
    }
    
    override public func reverseTransformedValue(_ value: Any?) -> Any? {
        guard let box = value as? WrapperClass else {
            return nil
        }

        do {
            let data = try NSKeyedArchiver.archivedData(
              withRootObject: box,
              requiringSecureCoding: true
          )
            return data
        } catch {
            return nil
        }
    }
}

The class TextDocumentClass contains the following variables NSAttributedString, String, Bool and Int

public class TextDocumentClass:NSObject, NSCoding, NSSecureCoding {
    public static var supportsSecureCoding: Bool = true
    
    var attributedText: NSAttributedString!
    var uuid:String!
    var isDeleted:Bool!
    var isChanged:Bool!
    var prevPageUUID:String!
    var nextPageUUID:String!
    var order:Int!
    var lastUpdatedDate:String!
    var isPDF: Bool!
    var pdfURL: String!
    var pdfPageNumber: Int!
    
    init (pAttributedText:NSAttributedString, pUUID:String, pPrevPageUUID:String, pNextPageUID:String, pOrder:Int, pIsDeleted: Bool, pIsChanged: Bool, pLastUpdatedDate: String, isPDF: Bool = false, pdfURL: String = "", pdfPageNumber: Int = -1) {
        self.attributedText = pAttributedText
        self.uuid = pUUID
        self.isDeleted = pIsDeleted
        self.isChanged = pIsChanged
        self.prevPageUUID = pPrevPageUUID
        self.nextPageUUID = pNextPageUID
        self.order = pOrder
        self.lastUpdatedDate = pLastUpdatedDate
        self.isPDF = isPDF
        self.pdfURL = pdfURL
        self.pdfPageNumber = pdfPageNumber
    }
    
    required public init?(coder aDecoder: NSCoder){
        self.attributedText = (aDecoder.decodeObject(of: NSAttributedString.self, forKey: "attributedText"))! 
        self.prevPageUUID = (aDecoder.decodeObject(of: NSString.self, forKey: "prevPageUUID") as? String)! 
        self.nextPageUUID = (aDecoder.decodeObject(of: NSString.self, forKey: "nextPageUUID") as? String)! 
        self.uuid = (aDecoder.decodeObject(of: NSString.self, forKey: "uuid") as? String)! 
        self.isChanged = (aDecoder.decodeObject(of: NSNumber.self, forKey: "isChanged")?.boolValue)! 
        self.isDeleted = (aDecoder.decodeObject(of: NSNumber.self, forKey: "isDeleted")?.boolValue)! 
        self.order = (aDecoder.decodeObject(of: NSNumber.self, forKey: "order")?.intValue)! 
        self.lastUpdatedDate = (aDecoder.decodeObject(of: NSString.self, forKey: "lastUpdatedDate") as? String)! 
        self.isPDF = aDecoder.decodeObject(of: NSNumber.self, forKey: "isPDF")?.boolValue ?? false 
        self.pdfURL = (aDecoder.decodeObject(of: NSString.self, forKey: "pdfURL") as? String ?? "") 
        self.pdfPageNumber = aDecoder.decodeObject(of: NSNumber.self, forKey: "PDFpageNumber")?.intValue ?? -1 
    }
    
    public func encode(with aCoder: NSCoder) {
        aCoder.encode(attributedText,forKey:"attributedText")
        aCoder.encode(prevPageUUID,forKey:"prevPageUUID")
        aCoder.encode(nextPageUUID,forKey:"nextPageUUID")
        aCoder.encode(uuid,forKey:"uuid")
        aCoder.encode(isChanged,forKey:"isChanged")
        aCoder.encode(isDeleted,forKey:"isDeleted")
        aCoder.encode(order,forKey:"order")
        aCoder.encode(lastUpdatedDate,forKey:"lastUpdatedDate")
        aCoder.encode(isPDF, forKey: "isPDF")
        aCoder.encode(pdfURL, forKey: "pdfURL")
        aCoder.encode(pdfPageNumber, forKey: "PDFpageNumber")
    }
    
    override public init() {
        self.attributedText = NSAttributedString()
        self.uuid = ""
        self.isDeleted = false
        self.isChanged = false
        self.prevPageUUID = ""
        self.nextPageUUID = ""
        self.order = -1
        self.lastUpdatedDate = ""
        self.isPDF = false
        self.pdfURL = ""
        self.pdfPageNumber = -1
    }
}

A little extra information not sure if it helps, i figure out how to get a error about why its nil

//this code line
let temp = try aDecoder.decodeTopLevelObject(of: [BaselineClass.self], forKey: "attributedStrings")
//gives this print in console
Allowed classes are:
 {(
    "'demo.BaselineClass' (0x100f6fc40) [/private/var/containers/Bundle/Application/EF7BF8EB-A98B-4B52-AE8F-1FB05F31ECC3/demo.app]"
)}" UserInfo={NSDebugDescription=value for key 'attributedStrings' was of unexpected class 'NSArray' (0x1fc4b89e0) [/System/Library/Frameworks/CoreFoundation.framework].
Allowed classes are:
 {(
    "'demo.BaselineClass' (0x100f6fc40) [/private/var/containers/Bundle/Application/EF7BF8EB-A98B-4B52-AE8F-1FB05F31ECC3/demo.app]"
)}}
//if i change the code line to use NSArray.self so it looks like this
let temp = try aDecoder.decodeTopLevelObject(of: NSArray.self, forKey: "attributedStrings")
//i get this in console instead
Allowed classes are:
 {(
    "'NSArray' (0x1fc4b89e0) [/System/Library/Frameworks/CoreFoundation.framework]"
)}" UserInfo={NSDebugDescription=value for key 'NS.objects' was of unexpected class 'demo.BaselineClass' (0x103363c40) [/private/var/containers/Bundle/Application/1E080145-14D1-4D03-9520-E87C39B8F2C7/demo.app].
Allowed classes are:
 {(
    "'NSArray' (0x1fc4b89e0) [/System/Library/Frameworks/CoreFoundation.framework]"
)}}

Any help in solving this is appreciated thanks.

Answer 1

After communication back and forth with Apple the following solved my problem. When decoding the array of classes se code

self.attributedStrings = aDecoder.decodeObject(of: [TextDocumentClass.self], forKey: "attributedStrings") as? [TextDocumentClass]

it should be changed to this.

self.attributedStrings = aDecoder.decodeObject(of: [NSArray.self, TextDocumentClass.self], forKey: "attributedStrings") as? [TextDocumentClass]

Then i also had some other small bug in my TextDocumentClass public initialiser where instead of decodeObject for bool and int i should use decodeBool and decodeInt32.