Saving custom object as core data property

Question

I am trying to save a custom class as a property of a core data object.

The Core Data object:

@objc(Safer)
class Safer: NSObject
{
@NSManaged var perakimFiles: [prayer]? //This line gives me an error saying that it cannot save a type that is not Obj. C
@NSManaged var titleEnglish: String?
@NSManaged var titleHebrew: String?
@NSManaged var parshaPerakim: [Int]?
@NSManaged var saferCode: String?
var titles: [[String]]
{
    get
    {
        var ret = [[String]]()
        var i = 0
        for file in perakimFiles!
        {
            ret.append([file.title, "\(i+1)"])
            i++
        }
        return ret
    }
}

init(_ _saferCode: SefarimCodes)
{
    super.init()
    self.saferCode = _saferCode.rawValue
}

init(_perakimFiles: [prayer], _titleEnglish: String, _titleHebrew: String)
{
    super.init()
    self.perakimFiles = _perakimFiles
    self.titleEnglish = _titleEnglish
    self.titleHebrew = _titleHebrew
}
init(_perakimFiles: [prayer], _titleEnglish: String, _titleHebrew: String, _parshaPerakim: [Int])
{
    super.init()
    self.perakimFiles = _perakimFiles
    self.titleEnglish = _titleEnglish
    self.titleHebrew = _titleHebrew
    self.parshaPerakim = _parshaPerakim
    self.saferCode = setTorahSaferCode()!.rawValue
    let config = self.configFromCode()
    self.perakimFiles = config.perakimFiles
}
}

Here is the prayer class that I am trying to save in the core data object:

class prayer
{
var url: NSURL
var title: String
var detail: String?

init(initURL: NSURL, initTitle: String)
{
    print("1")
    print("2")
    self.title = initTitle
    print("3")
    self.url = initURL
    print("4")
}

init(initURL: NSURL, initTitle: String, initDetail: String)
{
    self.url = initURL
    self.title = initTitle
    self.detail = initTitle
}
}

So what can I do to the prayer class to make it savable by the core data object? I need to also be able to use instances of the prayer class in other places of the code.

Answer 1

As mentioned, have your prayer class subclass NSObject and conform to NSCoding which requires two methods : -initWithCoder: and encodeWithCoder:

Once those are implemented, you can use NSKeyedArchiver/NSKeyedUnarchiver class methods to transform your objects into NSData objects and back, thus allowing you to store your objects as CoreData properties under the supported NSData type.