Encode complex object swift 3.0 - ios

Question

I already read several posts and tried every solution, nothing works in my case.
I am using this complex data structure and need to store array of DrawnObjects in file. But it crashing when it first came to encode a variable which itself is an array of Structure type. Any help ?
[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance 0x1702668c0
enum ArchiverKeys : String
{
case imageView = "ImageView"
case stateArray = "StateArray"
case bezierPathArray = "BezierPathArray"
case reactangleArray = "ReactangleArray"
case deleted = "Deleted"
}
struct RectanglePath {
var point1: CGPoint
var point2: CGPoint
var point3: CGPoint
var point4: CGPoint
}
struct StateObject {
var isAdd = true
var path = String()
}
class DrawObject: NSObject , NSCoding {
var ImageView = UIImageView()
var arrStates = [StateObject]()
var arrBezierPaths = [UIBezierPath]()
var rects = [RectanglePath]()
var deleted = false
override init() {
ImageView = UIImageView()
arrStates = []
arrBezierPaths = []
rects = []
deleted = false
}
func encode(with archiver: NSCoder) {
archiver.encode(self.ImageView, forKey:ArchiverKeys.imageView.rawValue )
archiver.encode(self.arrStates, forKey: ArchiverKeys.stateArray.rawValue)
archiver.encode(self.arrBezierPaths, forKey:ArchiverKeys.bezierPathArray.rawValue )
archiver.encode(self.rects, forKey: ArchiverKeys.reactangleArray.rawValue)
archiver.encode(self.deleted, forKey: ArchiverKeys.deleted.rawValue)
}
required convenience init(coder unarchiver: NSCoder) {
self.init()
self.ImageView = unarchiver.decodeObject(forKey: ArchiverKeys.imageView.rawValue) as! UIImageView
self.arrStates = unarchiver.decodeObject(forKey: ArchiverKeys.stateArray.rawValue) as! [StateObject]
self.arrBezierPaths = unarchiver.decodeObject(forKey: ArchiverKeys.bezierPathArray.rawValue) as! [UIBezierPath]
self.rects = unarchiver.decodeObject(forKey: ArchiverKeys.reactangleArray.rawValue) as! [RectanglePath]
self.deleted = (unarchiver.decodeObject(forKey: ArchiverKeys.deleted.rawValue) != nil)
}
}
func saveArrayTo(_ directoryName: String , arrayToSave: NSArray) {
// let encodedData = NSKeyedArchiver.archivedData(withRootObject: arrayToSave)
NSKeyedArchiver.archiveRootObject(arrayToSave, toFile: directoryName)
}
func loadArrayFrom(_ directoryName: String ) -> NSArray? {
let result = NSKeyedUnarchiver.unarchiveObject(withFile: directoryName)
return result as? NSArray
}

Answer 1

You cannot encode a Swift struct out of the box, you have to add a computed property and an init method to make the struct property list compliant
struct StateObject {
var isAdd = true
var path = ""
init(propertyList : [String:Any]) {
self.isAdd = propertyList["isAdd"] as! Bool
self.path = propertyList["path"] as! String
}
var propertyListRepresentation : [String:Any] {
return ["isAdd" : isAdd, "path" : path]
}
}
Now you can archive the array
archiver.encode(self.arrStates.map{$0.propertyListRepresentation}, forKey: ArchiverKeys.stateArray.rawValue)
and unarchive it
let states = unarchiver.decodeObject(forKey: ArchiverKeys.stateArray.rawValue) as! [[String:Any]]
self.arrStates = states.map { StateObject(propertyList: $0) }
Alternatively leave StateObject unchanged and
in encode(with replace the line
archiver.encode(self.arrStates, forKey: ArchiverKeys.stateArray.rawValue)
with
let arrStatesAsPlist = arrStates.map { return ["isAdd" : $0.isAdd, "path" : $0.path] }
archiver.encode(arrStatesAsPlist, forKey:ArchiverKeys.stateArray.rawValue)
in init(coder replace the line
archiver.encode(self.arrStates, forKey: ArchiverKeys.stateArray.rawValue)
with
let arrStatesAsPlist = unarchiver.decodeObject(forKey: ArchiverKeys.stateArray.rawValue) as! [[String:Any]]
arrStates = arrStatesAsPlist.map { StateObject(isAdd: $0["isAdd"] as! Bool, path: $0["path"] as! String) }
Notes:
Since you are assigning default values to all properties you can delete the entire init() method and the init() call in init(coder.
Don't use NSArray in Swift. Use a native Array
It's not a good idea to archive an UI element like UIImageView. Archive the image data.