How to save array of objects (with image variables) in Swift and Xcode? - swift

Question

I am wondering how to save an array of objects from the following class:
class CustomDocument: NSObject, NSCoding {
let name : String
let image : UIImage
init(n: String, i: UIImage){
name = n
image = i
}
//other code excluded
}
Originally, I saved this array to User Defaults. Because the objects took up a lot of space, it caused a lot of lag in the app.
What is the best way to save an array of data that takes up a lot of space?
Thank you so much for the help and all responses are appreciated.

Answer 1

Try this code, Hope it helps:
class CustomDocument: NSObject, NSCoding {
var name : String?
var image : UIImage?
func encode(with aCoder: NSCoder) {
aCoder.encode(name, forKey: "namekey")
if let imageData = image!.jpegData(compressionQuality: 1.0){
aCoder.encode(imageData, forKey: "imagekey")
}
UserDefaults.standard.synchronize()
}
required convenience init?(coder aDecoder: NSCoder) {
self.init()
if let name = (aDecoder.decodeObject(forKey: "namekey") as? String){
self.name = name
}
if let imageData = (aDecoder.decodeObject(forKey: "imagekey") as? Data){
if let image = UIImage(data: imageData){
self.image = image
}
}
}
}
func archiveDocument(document:CustomDocument) -> Data? {
do {
let archivedObject = try NSKeyedArchiver.archivedData(withRootObject: document, requiringSecureCoding: false)
return archivedObject
} catch {
// do something with the error
}
return nil
}
func unarchiveDocument(unarchivedObject:Data) -> CustomDocument? {
do {
if let document = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(unarchivedObject) as? CustomDocument {
return document
}
} catch {
// do something with the error
}
return nil
}
Example:
//Set the object, also you can use an array instead of an object
let obj = CustomDocument()
obj.name = "doc1"
obj.image = UIImage(named: "my_image")
if let archivedObject = archiveDocument(document: obj){
UserDefaults.standard.set(archivedObject, forKey: "obj")
}
//Get the object
if let archivedObject = UserDefaults.standard.data(forKey: "obj"){
obj = unarchiveDocument(unarchivedObject: archivedObject)
let myImage = obj?.image
}