Swift Property Wrapper for Saving Values to JSON in Documents Directory

DocDirectoryBacked.swift

@propertyWrapper struct DocDirectoryBacked<Value: Codable> {
    let location: String
    let documentDirectory = try! FileManager.default.url(for: .libraryDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
    
    private var dirToSave: URL {
        return documentDirectory.appendingPathComponent("\(location).json")
    }
    
    var wrappedValue: Value? {
        get {
            do {
                let data = try Data(contentsOf: dirToSave)
                return try JSONDecoder().decode(Value.self, from: data)
            } catch {
                return nil
            }
        }
        
        set {
            do {
                let data = try JSONEncoder().encode(newValue)
                try data.write(to: dirToSave)
            } catch {
                print("Error saving to \(dirToSave)")
            }
        }
    }
}