trjhtr

I'm using Swift 4.0 and I'm using UserDefaults in my project for storing Strings like login or something. I have a class:

class Cache: UserDefaultsManager {

 static var currentProfileID: Int? 
 get 
 return value(forKey: Constants.Cache.CurrentProfileID) as? Int
 
 set 
 set(newValue, forKey: Constants.Cache.CurrentProfileID)
 
 

 static var login: String? 
 get 
 return value(forKey: Constants.Cache.Login) as? String
 
 set 
 set(newValue, forKey: Constants.Cache.Login)
 
 

 // ... and there are more of this kind

, where UserDefaultsManager looks like this:

class UserDefaultsManager 
 private static var uds: UserDefaults 
 return UserDefaults.standard
 

 static func value(forKey: String) -> Any? 
 if let encoded = uds.object(forKey: forKey) as? Data 
 return NSKeyedUnarchiver.unarchiveObject(with: encoded)
 
 return nil 
 

 static func set(_ data: Any?, forKey: String) 
 let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: data as AnyObject)
 uds.set(encodedData, forKey: forKey)

 if (!uds.synchronize()) 
 NSLog("Failed sync UserDefaults?")
 
 

Constants.Cache is a structure that holds my keys. My question is:

What would be a good approach to make my Cache class lighter with
less code?

I imagine the final product should look like:

class Cache 
 static var hash: UDSObject<String>?
 static var currentProfileID: UDSObject<Int>?
 static var login: UDSObject<String>?
 static var selectedWindowID: UDSObject<Int>?

Your Cache class cannot be lighter than it already is. The most you can do is, introduce generics to remove the redundant casting every time you are trying to fetch from user defaults.

However, I see a major problem with the implementation here:

Is Cache also a UserDefaultsManager? Do you see Cache as something that extends the functionalities of the UserDefaultsManager class, or does your Cache use the functionalities of the UserDefaultsManager? I feel that composition is the way to go here than inheritance. I'd refactor this code to something like this:

protocol CacheHandling 
 func value<T>(forKey: String) -> T?
 func set<T>(_ data: T?, forKey: String)


extension CacheHandling 
 func value<T>(forKey: String) -> T? 
 let userDefaults = UserDefaults.standard
 if let encoded = userDefaults.object(forKey: forKey) as? Data 
 return NSKeyedUnarchiver.unarchiveObject(with: encoded) as? T
 
 return nil
 

 func set<T>(_ data: T?, forKey: String) 
 let userDefaults = UserDefaults.standard
 let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: data as AnyObject)
 userDefaults.set(encodedData, forKey: forKey)

 if (!userDefaults.synchronize()) 
 NSLog("Failed sync UserDefaults?")
 
 



struct Cache : CacheHandling 
 var currentProfileID: Int? 
 get 
 return value(forKey: Constants.Cache.CurrentProfileID)
 
 set 
 set(newValue, forKey: Constants.Cache.CurrentProfileID)
 
 

 var login: String? 
 get 
 return value(forKey: Constants.Cache.Login)
 
 set 
 set(newValue, forKey: Constants.Cache.Login)