In order to gain users, localizing our apps is essential since not everyone speaks the same language. Even if our app uses english strings, only a relatively thin slice of the entire global population understands it. We don’t want to lose the larger slice of the users, do we?

There are quite easy and quick ways to localize ours apps using external dependencies such as Applanga or Lokalise. I used both of them in the past, and I can vouch for them if you’re working on a enterprise level. They’re great but they’re a business and as any other: they…

It’s been a while we know it's possible to do snapshot testing on iOS. Recently, my friend Dariusz Rybicki introduced me to SnapshotTesting (from Stephen Celis and Brandon Williams ) and that’s what we’ll talk about today.

First things first

Let’s start by adding the following swift package:

https://github.com/pointfreeco/swift-snapshot-testing

Then, let’s create a simple screen and set view.backgroundColorto red:

In our unit test target, let’s create a test class, import SnapshotTesting and create a test case for this screen:

Right now, if we run the tests we’ll see an error saying that no reference was found on disk. This happens because…

Back in 2017, I watched Eric Cerney at the RWDevCon talking about MVVM and data bindings. What’s cool about it, is that it does the same thing that an observable would do in Rx with much less code.

Boxing

By overriding setters we can simulate observables. Skipping the MVVM refactoring, the most interesting thing here is Boxing. A technique where we wrap an object with generic type T and everytime its value gets updated a closure returns it.

This is great because it leaves our view controller completely isolated from our logic. It does exactly what a view controller should…

In the last couple of days I’ve been working on a QR code scanner feature (as you can probably tell by the topic of my last article) and I’ve stumbled upon a situation where I needed a semi-transparent overlay view which is completely transparent in the middle. In other words: a squared hole into an opaque view (or in this case semi-opaque).

In this pandemic you have probably seen many restaurants using QR codes for their menu in order to avoid using carton-made menu that could possibly be contaminated by other customers. Today I’ll quickly go through how to use QR (quick-response) codes and even regular barcodes in Swift.

How do we create QR codes or barcodes?

To generate QR codes or barcodes we need CoreImage framework which is used to generate images and apply filters but we will be fine by just importing UIKit instead.

A weird thing about using CoreImage filters is that they are initialized with a string from the generator protocol you want to use. …

Today we’ll go over how to use dependency injection with Swift 5.1 property wrappers. This approach is particularly interesting because its clean and very lightweight since it doesn’t require any third-party library.

When using property wrappers, we need to declare the wrappedValue. In the initializer we are resolving the dependency which will bring us the instance that was stored in the container for that type.

The container holds a private static variable which will be used on static functions such as resolve and register and it also holds a private dictionary for the dependencies. …

Today we’ll implement a custom transition, scaling an UIView from half-screen up to fullscreen using UIViewControllerAnimatedTransitioning . What will happen inside this custom transition is just some simple constraint animation but we could do pretty much anything.

In this article, we will cover the basics of Dependency Injection and how to apply it to an iOS project using an open-source framework called Swinject.

What is Dependency Injection?

Dependency Injection (DI) is a technique in which you set the dependencies of an entity from outside of its own scope, turning your system into loosely coupled modules. Imagine a class holding references to every other component of the app saving you from communication patterns between UIViewControllers for example.