Swift NSCoding Not working

Question

I\'m having trouble using NSCoding in Swift. I have attempted to implement the protocol but I get a crash whenever I call my save() method. Xcode p

Answer 1

class Student: NSObject, NSCoding {
    var name: String!
    var className: String!
    var rollNo: Int!
    var marks: [Float]!


    // MARK: NSCoding

    required convenience init(coder decoder: NSCoder) {
        self.init()
        self.name = decoder.decodeObjectForKey("name") as String?
        self.className = decoder.decodeObjectForKey("className") as String?
        self.rollNo = decoder.decodeIntegerForKey("rollNo")
        self.marks = decoder.decodeObjectForKey("marks") as [Float]!

    }

    func encodeWithCoder(coder: NSCoder) {
        coder.encodeObject(self.name, forKey: "name")
        coder.encodeObject(self.className, forKey: "className")
        coder.encodeInt(Int32(self.rollNo), forKey: "rollNo")
        coder.encodeObject(self.marks, forKey: "marks")

    }
}

Above class string,integer,array encoding are implemented.

suppose student is an instance of class Student

Archiving

1. File system :

   NSKeyedArchiver.archiveRootObject(student, toFile: "Here give your file path")
   

2. NSUserDefaults :

   let data = NSKeyedArchiver.archivedDataWithRootObject(student)
   NSUserDefaults.standardUserDefaults().setObject(data, forKey: "student")
   

Unarchiving

1. File system :

   NSKeyedUnarchiver.unarchiveObjectWithFile(student, toFile: "Here give your file path")
   

2. NSUserDefaults :

   if let data = NSUserDefaults.standardUserDefaults().objectForKey("student") as? NSData {
       let student = NSKeyedUnarchiver.unarchiveObjectWithData(data)
   }
   

Addit:

File path for saving / reading

func saveFileLocation() -> String {
    let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
    let documentDirectory = paths[0] as! String
    return documentDirectory.stringByAppendingPathComponent("savefile")
}