Question: What Is Lazy Loading In IOS Swift?

What are property wrappers in Swift?

What is a property wrapper in Swift.

A property wrapper is a generic structure that encapsulates read and write access to the property and adds additional behavior to it..

What is SDWebImage in IOS?

SDWebImage – Asynchronous image downloader with cache support as a UIImageView category.

What is weak in Swift?

A weak reference is just a pointer to an object that doesn’t protect the object from being deallocated by ARC. In Swift, all weak references are non-constant Optionals (think var vs. … let ) because the reference can and will be mutated to nil when there is no longer anything holding a strong reference to it.

How do I use SDWebImage?

If you use cocoapods, add pod ‘SDWebImage/GIF’ to your podfile. To use it, simply make sure you use FLAnimatedImageView instead of UIImageView . Note: there is a backwards compatible feature, so if you are still trying to load a GIF into a UIImageView , it will only show the 1st frame as a static image.

What is singleton in Swift?

Singleton is a creational design pattern, which ensures that only one object of its kind exists and provides a single point of access to it for any other code. Singleton has almost the same pros and cons as global variables. Although they’re super-handy, they break the modularity of your code.

What is lazy loading in Swift?

Lazy loading is initializing your properties only if / when they are called. This way, memory is not allocated for that property until absolutely necessary, and if the property is actually never used, the memory doesn’t get allocated at all. … The lazy keyword makes sure the property is only set if / when it’s called.

What is lazy loading example?

Examples of Lazy Loading As the name suggests, Infinite Scroll continuously loads content as the user scrolls down the page. … As the user scrolls down the page, placeholder images are replaced with thumbnails. After a certain number of images are displayed, a button allows the user to load additional images.

Why we use lazy VAR in Swift?

Swift has a mechanism built right into the language that enables just-in-time calculation of expensive work, and it is called a lazy variable. These variables are created using a function you specify only when that variable is first requested. … The lazy property is marked as lazy var .

What is enum in Swift?

An enumeration defines a common type for a group of related values and enables you to work with those values in a type-safe way within your code. Enumerations in Swift are first-class types in their own right. …

How do I know if lazy loading is working?

You can check to see that a module is indeed being lazy loaded with the Chrome developer tools. In Chrome, open the dev tools by pressing Cmd+Option+i on a Mac or Ctrl+Alt+i on a PC and go to the Network Tab. NOTE: Another important check is to make sure that a module loaded lazily is not loaded again.

What is lazy loading in IOS?

What is lazy loading : In layman language , lazy loading is used to download images.So that application does not freeze up while images are being downloaded. But from technical view point, it is the ability to specify the default routines that are compiled and loaded into memory during program launch.

What is lazy property in Swift?

Lazy Stored Properties. A lazy stored property is a property whose initial value isn’t calculated until the first time it’s used. … You must always declare a lazy property as a variable (with the var keyword), because its initial value might not be retrieved until after instance initialization completes.

Will set did set Swift?

It will only get called whenever you set the property by assigning a new value to it. It will always get called even if you assign the same value to it multiple times. willSet and didSet both have a default parameters newValue and oldValue. … These parameters are constants, hence you cannot mutate their values.

How can I get lazy loading?

Next, to lazy load a simple img element, all you need to do in your markup is: Question: What Is Lazy Loading In IOS Swift?

What is unowned self in Swift?

The most common place you’ll see unowned variables is with closures that declare [unowned self] – this means “I want to reference self inside this closure but I don’t want to own it.” Why unowned rather than weak ? Both would work, but let’s face it: if self is nil inside a closure, something has gone wrong!

How do I download asynchronous images in Swift?

Architecting Asynchronous Image Download and Caching in SwiftGiven the image URL, download the image from that URL.Download should happen in the background, and thus should not block the main thread.It may simultaneously be used by different parts of app.It should be thread safe.Should be configurable from outside.It should cache images.Apr 26, 2020

How do I cache an image in Swift?

Cache Images in a UICollectionView Using NSCache in Swift 5Understanding what an NSCache is and how to use it.Creating a centered UICollectionView layout.Executing image-loading tasks on a background thread.Understanding why it is better to use an NSCache instead of a plain Dictionary when we want to cache heavy objects.Sep 10, 2020

What is the use of lazy loading?

The benefits of lazy loading include: Reduces initial load time – Lazy loading a webpage reduces page weight, allowing for a quicker page load time. Bandwidth conservation – Lazy loading conserves bandwidth by delivering content to users only if it’s requested.