I want to have two versions of encodeWithCoder in the same class

Question

Let's say I have an object Person. (I know that Person has syntax errors. Please ignore those.)

class Person: NSObject, NSCoding {

    var name : String
    var salary: NSNumber


    // MARK: NSCoding

    required convenience init(coder decoder: NSCoder) {
        self.init()
        self.name = decoder.decodeObjectForKey("name") as String
        self.salary = decoder.decodeObjectForKey("salary") as NSNumber        
    }

    func encodeWithCoder(coder: NSCoder) {
        coder.encodeObject(self.name, forKey: "name")
        coder.encodeObject(self.salary, forKey: "salary")
    }

}

My question is: Is it possible to have two separate encodeWithCoder methods..one that includes salary in the archived object, and one that does not. Something like:

func encodeWithCoderPrivate(coder: NSCoder) {
    coder.encodeObject(self.name, forKey: "name")
    coder.encodeObject(self.salary, forKey: "salary")
}

func encodeWithCoderPublic(coder: NSCoder) {
    coder.encodeObject(self.name, forKey: "name")
}

What's the best way to go about implementing multiple archive methods in an NSObject, as a way of limiting the fields written to the archive?

score 0 · Accepted Answer · answered May 12 '15 at 23:46

Rather than trying to have 2 versions of it you should figure out what it is that determines which encoding you want to use, and make that a separate flag/field and encode that too.

func encodeWithCoder(coder: NSCoder) {
    coder.encodeObject(self.name, forKey: "name")
    if self.someFlag == true {
      coder.encodeObject(self.salary, forKey: "salary")
    }
    // encode flag as well
}

Then you can do the same thing in initWithCoder by parsing the flag first and decoding the rest of the fields based on its value.

This makes sense. Allows me to create a private copy of the data, then encode that copy. Just implemented and works perfectly. Thanks! — Four, May 13 '15 at 00:05

I want to have two versions of encodeWithCoder in the same class

1 Answers1