jeksys

    func listEntities(managedContext: NSManagedObjectContext, entityName: String, groupBy: Array<String>)->NSArray{
        
        var error: NSError?
        var results : NSArray = NSArray()
        
        let fetchRequest = NSFetchRequest(entityName: entityName)
        if groupBy.count > 0{
            fetchRequest.propertiesToGroupBy = groupBy
        }
        if let results = managedContext.executeFetchRequest(fetchRequest, error: &error) {

jeksys

extension NSTimer {
    class func scheduledTimerWithTimeInterval(interval: NSTimeInterval, repeats: Bool, handler: NSTimer! -> Void) -> NSTimer {
        let fireDate = interval + CFAbsoluteTimeGetCurrent()
        let repeatInterval = repeats ? interval : 0
        let timer = CFRunLoopTimerCreateWithHandler(kCFAllocatorDefault, fireDate, repeatInterval, 0, 0, handler)
        CFRunLoopAddTimer(CFRunLoopGetCurrent(), timer, kCFRunLoopCommonModes)
        return timer
    }
}
 

jeksys

func uicolorFromHex(rgbValue:UInt32)->UIColor{
    let red = CGFloat((rgbValue & 0xFF0000) >> 16)/256.0
    let green = CGFloat((rgbValue & 0xFF00) >> 8)/256.0
    let blue = CGFloat(rgbValue & 0xFF)/256.0

    return UIColor(red:red, green:green, blue:blue, alpha:1.0)
}

jeksys

extension String{
    
    var length: Int{
        get{
            return self.utf16Count
        }
    }
    
    func isValidEmail() -> Bool {
        let emailRegex = NSRegularExpression(pattern: "^[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}$", options: .CaseInsensitive, error: nil)

jeksys

extension UIColor {
   convenience init(red: Int, green: Int, blue: Int) {
       assert(red >= 0 && red <= 255, "Invalid red component")
       assert(green >= 0 && green <= 255, "Invalid green component")
       assert(blue >= 0 && blue <= 255, "Invalid blue component")

       self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0)
   }

   convenience init(netHex:Int) {

jeksys

let text = [UInt8]("hello!!!".utf8)
let cipher = [UInt8]("good".utf8)

var encrypted = [UInt8]()

// encrypt bytes
for t in enumerate(text) {
    encrypted.append(t.element ^ cipher[t.index%cipher.count])
}

jeksys

 a:  AM/PM
 A:	0~86399999 (Millisecond of Day)
 
 c/cc:	1~7 (Day of Week)
 ccc:	Sun/Mon/Tue/Wed/Thu/Fri/Sat
 cccc:	Sunday/Monday/Tuesday/Wednesday/Thursday/Friday/Saturday
 
 d:	1~31 (0 padded Day of Month)
 D:	1~366 (0 padded Day of Year) 
 

jeksys

private protocol _Optional {
    func unwrappedString() -> String
}

extension Optional: _Optional {
    private func unwrappedString() -> String {
        switch self {
        case .Some(let wrapped as _Optional): return wrapped.unwrappedString()
        case .Some(let wrapped): return String(wrapped)
        case .None: return String(self)

jeksys

extension NSData {
    
    func hexadecimal() -> String {
        var string = ""
        var byte: UInt8 = 0
        
        for i in 0 ..< length {
            getBytes(&byte, range: NSMakeRange(i, 1))
            string += String(format: "%02x", byte)
        }

jeksys

private protocol _Optional {
    func unwrappedString() -> String
}

extension Optional: _Optional {
    fileprivate func unwrappedString() -> String {
        switch self {
        case .some(let wrapped as _Optional): return wrapped.unwrappedString()
        case .some(let wrapped): return String(describing: wrapped)
        case .none: return String(describing: self)