Swift save cutom class in settings exception: 'NSInvalidArgumentException', reason: '*** -length only defined for abstract class -

hello try store custom object nsuserdefaults. used helpful post saving custom swift class nscoding userdefaults

but following exception when try out

2015-05-12 11:05:14.994 kirchnertime[4424:75095] * terminating app due uncaught exception 'nsinvalidargumentexception', reason: '* -length defined abstract class. define -[project length]!'

import foundation  @objc(project) public class projectjobentity: nsdata, nscoding   { private let _barcode: string private var _projectnumber: string private var _projectdescription: string private var _jobdescription: string  public var barcode: string {     { return self._barcode } }  public var projectnumber: string {     { return self._projectnumber }     set { self._projectnumber = newvalue } }  public var projectdescription: string {     { return self._projectdescription }     set { self._projectdescription = newvalue } }  public var jobdescription: string {     { return self._jobdescription }     set { self._jobdescription = newvalue } }  public init(barcode: string, projectnumber: string, projectdescription: string, jobdescription: string) {     self._barcode = barcode     self._projectnumber = projectnumber     self._projectdescription = projectdescription     self._jobdescription = jobdescription      super.init() }   public init(barcode: string) {     self._barcode = barcode     self._projectnumber = ""     self._projectdescription = ""     self._jobdescription = ""      super.init() }  override public func encodewithcoder(acoder: nscoder) {     acoder.encodeobject(self._barcode, forkey: "barcode")     acoder.encodeobject(self._projectnumber, forkey: "projectnumber")     acoder.encodeobject(self._projectdescription, forkey: "projectdescription")     acoder.encodeobject(self._jobdescription, forkey: "jobdescription") }  required public init(coder adecoder: nscoder) {     self._barcode = adecoder.decodeobjectforkey("barcode") as! string     self._projectnumber = adecoder.decodeobjectforkey("projectnumber") as! string     self._projectdescription = adecoder.decodeobjectforkey("projectdescription") as! string     self._jobdescription = adecoder.decodeobjectforkey("jobdescription") as! string      super.init(coder: adecoder) } 

this object should stored.

 public func savesettings() {     let settings = nsuserdefaults.standarduserdefaults()     settings.setvalue(self._cardnumber, forkeypath: cardnumberkey)      settings.setobject(nskeyedarchiver.archiveddatawithrootobject(projectjobentity(barcode: "test")), forkey: "project") } 

and how try it.

i had same exception.

i use nsobject parent class.

use under code

    public class projectjobentity: nsobject     {         private let _barcode: string         private var _projectnumber: string         private var _projectdescription: string         private var _jobdescription: string          public var barcode: string             {             { return self._barcode }         }          public var projectnumber: string             {             { return self._projectnumber }             set { self._projectnumber = newvalue }         }          public var projectdescription: string             {             { return self._projectdescription }             set { self._projectdescription = newvalue }         }          public var jobdescription: string             {             { return self._jobdescription }             set { self._jobdescription = newvalue }         }          public init(barcode: string, projectnumber: string, projectdescription: string, jobdescription: string)         {             self._barcode = barcode             self._projectnumber = projectnumber             self._projectdescription = projectdescription             self._jobdescription = jobdescription              super.init()         }           public init(barcode: string)         {             self._barcode = barcode             self._projectnumber = ""             self._projectdescription = ""             self._jobdescription = ""              super.init()         }          public func encodewithcoder(acoder: nscoder)         {             acoder.encodeobject(self._barcode, forkey: "barcode")             acoder.encodeobject(self._projectnumber, forkey: "projectnumber")             acoder.encodeobject(self._projectdescription, forkey: "projectdescription")             acoder.encodeobject(self._jobdescription, forkey: "jobdescription")         }          public func initwithcoder(adecoder: nscoder) -> projectjobentity         {             let barcode = adecoder.decodeobjectforkey("barcode") as! string             let projectnumber = adecoder.decodeobjectforkey("projectnumber") as! string             let projectdescription = adecoder.decodeobjectforkey("projectdescription") as! string             let jobdescription = adecoder.decodeobjectforkey("jobdescription") as! string              return projectjobentity(barcode: barcode, projectnumber: projectnumber, projectdescription: projectdescription, jobdescription: jobdescription)         }     }