Swift 3: Protocol Part 1



Introduction:


Protocol main and widely used concept in objective c and swift both. So here we will be discussing in swift. We have two parts for a protocol. Part -1, will have basic terminology and concept to understand it and Part 2 and Part 3 will have some more drills in detail about it.

The protocol you can think of “Contract” between two bodies. If anyone has acquired it then, that has to follow certain rules to incorporate the action of the contract. Same way Protocol in objective will act in the same way.

Protocols define the set of methods, properties, and required pieces of functionality. Any type whoever going to conform it will have to conform first and then implement the requirement. The protocol can be adopted by a class, struct, enum. Any type that fulfilling the requirement of that protocol is said to conform to that protocol.


If you conform to the protocol then we need to implement the requirement. We can extend the protocol as well to extend the functionality of any type mentioned above.

We will learn the following things:
  • Syntax
  • How to adopt or conform a protocol?
  • How to create delegate property of protocol?
  • How to call the method using delegate property?
  • Implement the protocol method in the conforming class.


Syntax:


protocol myProtocol {

    // protocol definition

}


Adopting or conforming Protocol(s):

1) conforming one protocol at a time 


class Car: myProtocol {

    func customMethod()

}


2) conforming multiple protocols 

You can adopt a protocol after placing protocol’s name after the custom type and after the: (semicolon).


class Car: Protocol1,Protocol2,Protocol3 {

    

}


NOTE:
If a Certain type has the super class then after: super class must come and then after that protocols name separated by the comma. The compiler will error if you try to place the super class name after the protocol name, “SuperClass” must appear first in the inheritance clause.


class Car: CarBaseClass, Protocol1,Protocol2,Protocol3 {

    

}


As CarBaseClass is the super class of Car class.

Delegate Property:




class Car: myProtocol {


    var delegate:myProtocol?

}



Calling Method using delegate:

For this method, you need to call from another source.
delegate?.customMethod() // ? will make sure if delegate is then next thing will not be executed.

Implement Protocol method:




class Car: myProtocol  {


    func customMethod() {

    }

}



That’s all from the basics of Protocol. I will come with some more drill-down details of Protocol in Part - 2. Warm welcome for your suggestions to make this blog clearer.

Wrapping Up: 

As you have learned about the basics of the protocol.  We will continue with the next part of it stay tuned for next. blog.

Happy Coding 😊




Location: Bangalore Metropolitan Area, Karnataka

Comments

Post a Comment

Popular posts from this blog

Copy Vs Mutable Copy in iOS

It's found very confusing for most of the folks, who is not having much experience in Objective-C. Before starting I just to say: Just remember below lines- 1 - copy always creates an immutable copy means you can not modify the object. 2 - mutableCopy always creates a mutable copy  means you can modify the object Here onwards I try to explain copy and mutable copy with some examples: copy: NSArray *obj = [ NSArray arrayWithObjects : @"1" , @"2" , nil ]; NSArray *copyObj = [obj copy ]; NSArray *mutableObj = [obj mutableCopy ]; When you try to see the details of copyObj its clearly shows  __NSArrayI which tells that you can not modify this object Printing description of copyObjy: <__nsarrayi 0x6080000238a0="">( 1, 2 ) Same way  When you try to see the details of mutableObj its clearly shows  __NSArrayM which tells that you can modify this object Printing description of mutableObjy: <__nsarr
Read more

How to Disable iOS/iPad App availability on Mac Store, Silicon?

Image
As we all know that iPhone and iPad apps will be available on Mac App Store on Apple silicon. So if you are willing not to serve on Mac App Store we need to do some changes to  our deployed builds. As we know this is going to happen automatically on Apple Silicon Mac for all your iOS/iPad App. Though there will be no modification on the App.  Thank God !! There is no extra work for porting to the Mac App.   Do not worry about the framework and all they will work just fine as they were working on the iPhone and iPad, the framework will be intact as it is. So Happy 😊 How we can identify the app on the Mac App Store, Users will be able to find iPhone and iPad apps right on the Mac App Store. These apps will be distinguished by the “ Designed for iPhone ” and “ Designed for iPad ” badge next to the app icon. You should not worry about the rating and review as well those will be independently mapped. Managing Mac App Store availability.   By default, your apps will be pub
Read more

Closures in Swift - Part 1

Closures: Closures in Swift are similar to blocks in C and Objective-C and to lambdas in other programming languages.  Closures can capture and store references to any constants and variables from the context in which they are defined .  Swift handles all of the memory management of capturing for you. Declaration: You can declare as below: { ( parameters ) -> return type in statements } The  parameters  in closure expression syntax can be in-out parameters, but they can’t have a default value.  A simple closure can be declared as below as well let  newClosures = {      print ( "This is new basic closure which very simple to create and call" ) } we can call using like this  newClosures (). Closure With Parameter:  we passed the parameter in the closure and can pass the string as below. The basic different closure and function is closure do not use "Argument Label" while defining and
Read more