What are Segues And Their Use In iOS Swift

Segues: In iOS development segues use to define transition from one view controller to other view controller in storyboard file.Any clickable or gesture recognisable element can be source of segue and a view controller that we want to display will be the source of segue. so basically segue present a view controller but we can also use a segue to dismiss in case of unwind segue.

Creating a Segue : For creating a segue click on source (i.e from button , gesture recogniser or view controller) and right click + drag  to destination view controller. There can be multiple segues from one view controller and similarly there can be multiple segues to a single view controllers. To handle multiple segues we can assign unique segue identifiers to segues.

Types of Segues : There are five types of pre-defined segues we can use , although we can define our own custom segues too. 

a) Show (or Push) :  This type of segue present the view controller over the source view controller. e.g.. In case of navigation controllers It pushes the view controller in navigation stack.

b) Show Details :  It is used with UISplitViewController , It replaces a view controller with other view controller i.e like showing the details of selected content.

c) Present Modally : Displays the new view controller modally.

d) Present as Popover : It present a view controller as a popover, In case of iPhones it behave as Persent Modally segues , but in case of iPads the content displayed as popover.

Passing Data : We can pass data between view controllers on transitions. To fire a segue programatically we have to call a method 

 self.performSegue(withIdentifier: “segueIdentifier”, sender: self)

before transition we can override prepare method and an instance of view controller can be used to set values

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
 if segue.identifier == "segueIdentifier" 
 var vc = segue.destinationViewController as! DestinationViewController
 vc.data = "Data to pass"
 }
}

Custom Segues: We can implement custom segues as well and define our own transitions and behaviour too. All we need to do is to create a UIStoryboardSegue subclass and implement own perform  method where we define the behaviour.

Thanks,