What is delegate design pattern in iOS?

What is delegate design pattern in iOS?

According to Apple: Delegation is a simple and powerful pattern in which one object in a program acts on behalf of, or in coordination with, another object. The delegating object keeps a reference to the other object–the delegate–and at the appropriate time sends a message to it.

What is delegate in iOS with example?

Example for Delegate Let’s assume an object A calls an object B to perform an action. Once the action is complete, object A should know that B has completed the task and take necessary action. This is achieved with the help of delegates. A will implement the delegate methods of B.

What is the delegate pattern Swift?

The core purpose of the delegate pattern is to allow an object to communicate back to its owner in a decoupled way. By not requiring an object to know the concrete type of its owner, we can write code that is much easier to reuse and maintain.

What is iOS delegate?

Delegate is simply just a means of communication between objects of iOS applications. You can think delegation as a simple way of connecting objects and communicate with each other. In other words we can say that delegate allows one object to send message to other object when any event occurs.

What is difference between delegate and datasource in iOS?

A data source is almost identical to a delegate. The difference is in the relationship with the delegating object. Instead of being delegated control of the user interface, a data source is delegated control of data.

What is the difference between AppDelegate and SceneDelegate?

The AppDelegate will be responsible for the application lifecycle and setup. The SceneDelegate will be responsible for what is shown on the screen (Windows or Scenes) handle and manage the way your app is shown.

How does delegate work in iOS?

A delegate allows one object to send messages to another object when an event happens. The delegate may respond to the message by updating the appearance or state of itself or other objects in the application, and in some cases, it can return a value that affects how an impending event is handled.

What is difference between protocol and delegate in Swift?

We can say Protocol as a set of rules. That rules can be optional or required like we have to use in protocol. Delegates is a message passing technique in objective C and swift. An object has to take care of that message.

What are the methods of delegation?

Delegation Techniques: 5 Steps for Putting Your Delegation Plan into Action

• Understand what you want to delegate and why.
• Prepare a delegation plan and strategy.
• Choose the right person for the task.
• Set expectations, both for outcomes and the process.
• Provide feedback, support and resources.

What are delegates and how are they different from data source?

Delegate relates to the UI and User actions against the cells and table. Data Source deals with the editing, population and displaying of data on the tableview.

Which method of AppDelegate is called first in iOS?

AppDelegate. UIViewController is allocated as the window’s initial view controller. To make the window visible, makeKeyAndVisible method is called.

What is the use of SceneDelegate in iOS?

Use your UISceneDelegate object to manage life-cycle events in one instance of your app’s user interface. This interface defines methods for responding to state transitions that affect the scene, including when the scene enters the foreground and becomes active, and when it enters the background.

How is the delegate pattern used in iOS?

It refers to the delegate design pattern that enables a class or structure to hand off some of its responsibilities to an instance of another type. This enables the delegate to customize the base class. Delegation is frequently used in practical iOS development. The iOS delegate pattern has a significant impact on the platforms of Apple.

What are the parts of a delegation pattern?

This pattern has three parts: An object needing a delegate, also known as the delegating object. It’s the object that has a delegate. The delegate is usually held as a weak property to avoid a retain cycle where the delegating object retains the delegate, which retains the delegating object.

When do you use delegation pattern in Swift?

Written by LearnAppMaking on August 5 2020 in App Development, iOS, Swift Delegation, also known as the Delegate pattern, is frequently used in practical iOS development. It’s a must-have in your iOS developer’s toolbox, and today we’re going to figure out how delegation works.

What does delegation mean in the Apple documentation?

The official Apple documentation defines delegation as: Delegation is a design pattern that enables a class to hand off (or “delegate”) some of its responsibilities to an instance of another class. That’s quite complex, so let’s break it down… Think about delegation in the real world.