Where do I put common utility functions in iOS 8 + Swift

Question

I have the following method (for instance) that I'd like to be able to use from any ViewController in an iOS + Swift project:

func initializeBlurEffectOnGivenUIView(UIViewToBeBlurred: UIView) {

    let UIViewToBeBlurredHeight = UIViewToBeBlurred.frame.size.height
    let UIViewToBeBlurredWidth = UIViewToBeBlurred.frame.size.width
    let UIViewToBeBlurredX = UIViewToBeBlurred.frame.origin.x
    let UIViewToBeBlurredY = UIViewToBeBlurred.frame.origin.y

    let blurEffect:UIBlurEffect = UIBlurEffect(style: UIBlurEffectStyle.Light)
    let vibrancyEffect = UIVibrancyEffect(forBlurEffect: blurEffect)

    let vibrancyEffectView = UIVisualEffectView(effect: vibrancyEffect)
    let blurEffectView:UIVisualEffectView = UIVisualEffectView(effect: blurEffect)
    blurEffectView.frame = CGRectMake(UIViewToBeBlurredX, UIViewToBeBlurredY, UIViewToBeBlurredWidth, UIViewToBeBlurredHeight)
    blurEffectView.contentView.addSubview(vibrancyEffectView)

    UIViewToBeBlurred.addSubview(blurEffectView)
}

I have more common helpers such as there that I'd like to make available as well. How do I structure the application to achieve this?

score 18 · Answer 1 · edited May 23 '17 at 12:16

18

If the function is to be a free global, put the function at the top level of any file. (Just don't accidentally repeat yourself and put the same function at the top level of all files.) That, for example, is what I do with the delay utility function I describe here: dispatch_after - GCD in swift?

In the particular case of the example you gave, however, I'd probably put it in an extension on UIView. I'd rewrite it as an instance method, so that instead of blurring another view, we'd start with an existing view and blur self.

edited May 23 '17 at 12:16

Community

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answered Dec 13 '14 at 18:20

matt

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Thanks for the helpful answer. I'm marking Mike's answer because of the example code. – John Doe Dec 13 '14 at 23:48
3

This should be the correct answer. The question itself mentions common utility functions. – ChrisH Jul 16 '15 at 15:51

score 7 · Accepted Answer · answered Dec 13 '14 at 19:04

Use an extension, like this:

extension UIView {
    func initializeBlurEffect() {

        let height = self.frame.size.height
        let width = self.frame.size.width
        let x = self.frame.origin.x
        let y = self.frame.origin.y

        let blurEffect:UIBlurEffect = UIBlurEffect(style: UIBlurEffectStyle.Light)
        let vibrancyEffect = UIVibrancyEffect(forBlurEffect: blurEffect)

        let vibrancyEffectView = UIVisualEffectView(effect: vibrancyEffect)
        let blurEffectView:UIVisualEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = CGRectMake(x, y, width, height)
        blurEffectView.contentView.addSubview(vibrancyEffectView)

        self.addSubview(blurEffectView)
    }
}

Then call it like this:

myview.initializeBlurEffect()

I like the idea of an extension. And, what location would you put this extension? — John Doe, Dec 13 '14 at 23:03

score 2 · Answer 3 · answered May 31 '16 at 12:35

If you want to access this functions globally then you can put it on top of any file or to be systematic create a normal swift file and add it there.

OR If you want to access it in UIViews or viewcontroller, you can create extension of uiview(as suggested by @Mike)

Dhaval H. Nena · Answer 4 · 2017-06-01T10:01:38.820

You can create common class for that as below:

class Utils {

//MARK:- STRING FROM DICT
func getStringFromDictionary(dict:Any) -> String{
    var strJson = ""
    do {
        let data = try JSONSerialization.data(withJSONObject: dict, options: JSONSerialization.WritingOptions.prettyPrinted)
        strJson = String(data: data, encoding: String.Encoding.utf8)!
    } catch let error as NSError {
        print("json error: \(error.localizedDescription)")
    }

    return strJson
}



//MARK:- ALERT
func showAlertWithTitleFromVC(vc:UIViewController, title:String, andMessage message:String, buttons:[String], completion:((_ index:Int) -> Void)!) -> Void {

    let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
    for index in 0..<buttons.count  {

        //      alertController.setValue(NSAttributedString(string: title, attributes: [NSFontAttributeName : UIFont.appFont_OpenSans_Regular(fontSize: 15),NSForegroundColorAttributeName : BLACK_COLOR]), forKey: "attributedTitle")
        //
        //      alertController.setValue(NSAttributedString(string: message, attributes: [NSFontAttributeName : UIFont.appFont_OpenSans_Regular(fontSize: 13),NSForegroundColorAttributeName : APP_COLOR_BLUE_1]), forKey: "attributedMessage")


        let action = UIAlertAction(title: buttons[index], style: .default, handler: {
            (alert: UIAlertAction!) in
            if(completion != nil){
                completion(index)
            }
        })

        //      action.setValue(APP_COLOR_BLUE_2, forKey: "titleTextColor")
        alertController.addAction(action)
    }
    vc.present(alertController, animated: true, completion: nil)
}


//MARK:- ACTION SHEET
func showActionSheetWithTitleFromVC(vc:UIViewController, title:String, andMessage message:String, buttons:[String],canCancel:Bool, completion:((_ index:Int) -> Void)!) -> Void {

    let alertController = UIAlertController(title: title, message: message, preferredStyle: .actionSheet)

    alertController.setValue(NSAttributedString(string: title, attributes: [NSFontAttributeName : UIFont.appFont_OpenSans_Regular(fontSize: 15),NSForegroundColorAttributeName : BLACK_COLOR]), forKey: "attributedTitle")
    alertController.setValue(NSAttributedString(string: message, attributes: [NSFontAttributeName : UIFont.appFont_OpenSans_Regular(fontSize: 13),NSForegroundColorAttributeName : APP_COLOR_BLUE_1]), forKey: "attributedMessage")


    for index in 0..<buttons.count  {

        let action = UIAlertAction(title: buttons[index], style: .default, handler: {
            (alert: UIAlertAction!) in
            if(completion != nil){
                completion(index)
            }
        })

        action.setValue(APP_COLOR_BLUE_2, forKey: "titleTextColor")
        alertController.addAction(action)
    }

    if(canCancel){
        let action = UIAlertAction(title: "Cancel", style: .cancel, handler: {
            (alert: UIAlertAction!) in
            if(completion != nil){
                completion(buttons.count)
            }
        })
        action.setValue(APP_COLOR_BLUE_2, forKey: "titleTextColor")
        alertController.addAction(action)
    }

    vc.present(alertController, animated: true, completion: nil)
}

//MARK:- INTERNET CHECK
func IS_INTERNET_AVAILABLE() -> Bool{

    return AIReachabilityManager.shared.isInternetAvailableForAllNetworks()
}


let INTERNET_MESSAGE:String = "Oops! It seems that you're not connected to the Internet, connect and try again"//"No internet connection, Please try later"
func SHOW_INTERNET_ALERT(){
    showAlertWithTitleFromVC(vc: (appDelegate.window?.rootViewController)!, title: APP_NAME, andMessage: INTERNET_MESSAGE, buttons: ["Dismiss"]) { (index) in
    }
}



//MARK:- CUSTOM LOADER

func SHOW_CUSTOM_LOADER(){
    SHOW_CUSTOM_LOADER_WITH_TEXT(text: "")
}

func SHOW_CUSTOM_LOADER_WITH_TEXT(text:String){

    SVProgressHUD.setDefaultStyle(.custom)
    SVProgressHUD.setDefaultMaskType(.custom)
    SVProgressHUD.setDefaultAnimationType(.flat)

    SVProgressHUD.setBackgroundColor(UIColor.clear)
    SVProgressHUD.setRingRadius(30)
    SVProgressHUD.setRingThickness(5)
    SVProgressHUD.setForegroundColor(WHITE_COLOR)

    if(text.characters.count > 0){
        SVProgressHUD.show(withStatus: text)
    }else{
        SVProgressHUD.show()
    }
}

func HIDE_CUSTOM_LOADER(){
    SVProgressHUD.dismiss()
}

//MARK:- USER DEFAULTS

func setUserDefaultsFor(object:AnyObject, with key:String) {
    UserDefaults.standard.set(object, forKey: key)
    UserDefaults.standard.synchronize()
}

func getUserDefaultsForKey(key:String) -> AnyObject? {
    return UserDefaults.standard.object(forKey: key) as AnyObject?
}

func removeUserDefaultsFor(key:String) {
    UserDefaults.standard.removeObject(forKey: key)
    UserDefaults.standard.synchronize()
}



//MARK:- PROPORTIONAL SIZE
let SCREEN_HEIGHT = UIScreen.main.bounds.size.height
let SCREEN_WIDTH = UIScreen.main.bounds.size.width

func GET_PROPORTIONAL_WIDTH (width:CGFloat) -> CGFloat {
    return ((SCREEN_WIDTH * width)/750)
}
func GET_PROPORTIONAL_HEIGHT (height:CGFloat) -> CGFloat {
    return ((SCREEN_HEIGHT * height)/1334)
}



//MARK:- NETWORK ACTIVITY INDICATOR

func SHOW_NETWORK_ACTIVITY_INDICATOR(){
    UIApplication.shared.isNetworkActivityIndicatorVisible =  true
}

func HIDE_NETWORK_ACTIVITY_INDICATOR(){
    UIApplication.shared.isNetworkActivityIndicatorVisible =  false
}


//Check IsiPhone Device
func IS_IPHONE_DEVICE()->Bool{
    let deviceType = UIDevice.current.userInterfaceIdiom == .phone
    return deviceType
}

//Check IsiPad Device
func IS_IPAD_DEVICE()->Bool{
    let deviceType = UIDevice.current.userInterfaceIdiom == .pad
    return deviceType
}

//iPhone 4 OR 4S
func IS_IPHONE_4_OR_4S()->Bool{
    let SCREEN_HEIGHT_TO_CHECK_AGAINST:CGFloat = 480
    var device:Bool = false

    if(SCREEN_HEIGHT_TO_CHECK_AGAINST == SCREEN_HEIGHT) {
        device = true
    }
    return device
}

func proportionalFontSize() -> CGFloat {

    var sizeToCheckAgainst = self

    if(IS_IPAD_DEVICE())    {
        sizeToCheckAgainst += 12
    }
    else {
        if(IS_IPHONE_6P_OR_6SP()) {
            sizeToCheckAgainst += 1
        }
        else if(IS_IPHONE_6_OR_6S()) {
            sizeToCheckAgainst += 0
        }
        else if(IS_IPHONE_5_OR_5S()) {
            sizeToCheckAgainst -= 1
        }
        else if(IS_IPHONE_4_OR_4S()) {
            sizeToCheckAgainst -= 2
        }
    }
    return sizeToCheckAgainst
}

//iPhone 5 OR OR 5C OR 4S
func IS_IPHONE_5_OR_5S()->Bool{
    let SCREEN_HEIGHT_TO_CHECK_AGAINST:CGFloat = 568
    var device:Bool = false
    if(SCREEN_HEIGHT_TO_CHECK_AGAINST == SCREEN_HEIGHT) {
        device = true
    }
    return device
}

//iPhone 6 OR 6S
func IS_IPHONE_6_OR_6S()->Bool{
    let SCREEN_HEIGHT_TO_CHECK_AGAINST:CGFloat = 667
    var device:Bool = false

    if(SCREEN_HEIGHT_TO_CHECK_AGAINST == SCREEN_HEIGHT) {
        device = true
    }
    return device
}

//iPhone 6Plus OR 6SPlus
func IS_IPHONE_6P_OR_6SP()->Bool{
    let SCREEN_HEIGHT_TO_CHECK_AGAINST:CGFloat = 736
    var device:Bool = false

    if(SCREEN_HEIGHT_TO_CHECK_AGAINST == SCREEN_HEIGHT) {
        device = true
    }
    return device
}

//MARK:- DEVICE ORIENTATION CHECK
func IS_DEVICE_PORTRAIT() -> Bool {
    return UIDevice.current.orientation.isPortrait
}

func IS_DEVICE_LANDSCAPE() -> Bool {
    return UIDevice.current.orientation.isLandscape
}


//MARK:- SYSTEM VERSION CHECK
func SYSTEM_VERSION_EQUAL_TO(version: String) -> Bool {
    return UIDevice.current.systemVersion.compare(version,
                                                  options: NSString.CompareOptions.numeric) == ComparisonResult.orderedSame
}

func SYSTEM_VERSION_GREATER_THAN(version: String) -> Bool {
    return UIDevice.current.systemVersion.compare(version,
                                                  options: NSString.CompareOptions.numeric) == ComparisonResult.orderedDescending
}

func SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(version: String) -> Bool {
    return UIDevice.current.systemVersion.compare(version,
                                                  options: NSString.CompareOptions.numeric) != ComparisonResult.orderedAscending
}

func SYSTEM_VERSION_LESS_THAN(version: String) -> Bool {
    return UIDevice.current.systemVersion.compare(version,
                                                  options: NSString.CompareOptions.numeric) == ComparisonResult.orderedAscending
}

func SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(version: String) -> Bool {
    return UIDevice.current.systemVersion.compare(version,
                                                  options: NSString.CompareOptions.numeric) != ComparisonResult.orderedDescending
}

}

Where do I put common utility functions in iOS 8 + Swift

4 Answers4