NSCoder extension for working with CodingKeys

NSCoder+CodingKeys.swift

import Foundation
import QuartzCore

extension NSCoder {
    public func decodeIfPresent<T>(_ valueType: T.Type, forKey key: CodingKey) -> T? {
        guard self.containsValue(forKey: key.stringValue) else { return nil }
        return self.decodeObject(forKey: key.stringValue) as? T
    }

    public func decodeCGRectIfPresent(forKey key: CodingKey) -> CGRect? {
        guard self.containsValue(forKey: key.stringValue) else { return nil }
        return self.decodeCGRect(forKey: key.stringValue)
    }
}