Trying to save an array into UserDefaults - ios

Question

In my code, data is an array of format [String : Any], I'm trying to store it in userdefaults
let userDefaults = UserDefaults.standard
let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: data)
userDefaults.set(encodedData, forKey: "data")
userDefaults.synchronize()
but I get this error:
-[Features encodeWithCoder:]: unrecognized selector sent to instance
what I'm doing wrong?

Answer 1

You can only store several types of objects in UserDefaults like Int, String, Float, Double, Bool, URL, Data or collection of these types. However according to apple:
If you want to store any other type of object, you should typically
archive it to create an instance of NSData.
Luckily Apple released Codable so any class or struct conforming to Codable can be converted to and from Data.
First conform your dataModel to Codable
struct Features : Codable {
var feature1:String?
var feature2:String?
}
then after you create you objects and add them to the array
let feature1 = Features(feature1: "awesome", feature2: "World")
let feature2 = Features(feature1: "Hello", feature2: "World")
arrayOfFeatures = [feature1,feature2]
you can use save them like this:
func saveInUserDefault(with arrayOfFeatures:[Features]){
do{
UserDefaults.standard.set(try PropertyListEncoder().encode(arrayOfFeatures), forKey: "data")
UserDefaults.standard.synchronize()
}
catch
{
print(error.localizedDescription)
}
}
and get them with like this:
func getDataFromArray(){
if let savedData: Data = UserDefaults.standard.data(forKey: "data"){
do
{
arrayOfFeatures = try PropertyListDecoder().decode([Features].self, from: savedData)
for feature in arrayOfFeatures
{
print(feature.feature1)
print(feature.feature2)
}
}
catch
{
print(error.localizedDescription)
}
}
}
saveInUserDefault(with: arrayOfFeatures)