Replacing Completion Handlers with Futures

Building Reactive Applications With Combine

In the previous episode, you learned about futures and promises. In this episode, I show you how to use them in a project.

in Programming

Futures and Promises

Building Reactive Applications With Combine

Earlier in this series, you learned how a subject can bridge the gap between imperative programming and reactive programming. While subjects are convenient in many ways, they are not always the best option. The Combine framework provides another option. In this episode, we zoom in on futures and promises to bridge the gap between imperative programming and reactive programming.

in Programming

Five Signs of Code Smell in Swift

The first application I published on the App Store was littered with code smells, bad practices, and anti-patterns. The application worked, but it was a challenge to maintain. Adding features to a large, complex project becomes increasingly difficult if it lacks direction and structure.

in Patterns

Avoiding Infinite Loops

Building Reactive Applications With Combine

Infinite loops are every developer's nightmare, especially if they have disastrous consequences. You need to be mindful of infinite loops when working with Combine or any other reactive framework. The difficulty is that it isn't always obvious that you created an infinite loop. As a matter of fact, we introduced an infinite loop earlier in this series. You receive a bonus point if you can spot it.

in Programming

Seven Xcode Tricks Every Developer Should Know

To be productive and efficient, you need to know your tools. For a Swift developer, that means mastering Xcode. While Xcode is a complex piece of software with a fairly steep learning curve, the tricks I show you in this episode should significantly boost your productivity.

in Xcode

Image Caching with Kingfisher

Image Caching in Swift

In the previous episodes, we implemented a service to fetch and cache remote images. Even though the service we built is pretty flexible, some applications require a more powerful solution and more options to fit their needs. This episode focuses on Kingfisher, a popular, open source library to fetch and cache remote images. You learn how to integrate Kingfisher in a project using CocoaPods. I show you how Kingfisher differs from the service we created earlier in this series and we take a peek under the hood to learn how Kingfisher does its magic.

in Networking

Limiting the Cache on Disk

Image Caching in Swift

Earlier in this series, you learned that a cache on disk has a number of benefits. It persists the cache across launches and it can be used to seed a cache in memory. Even though modern devices have plenty of disk space, we need to be mindful of the space the cache on disk takes up on the user's device. Applications like Twitter and Instagram fetch hundreds if not thousands of images. Even if those images are optimized and small in size, the cache on disk can grow quickly, taking up a non-trivial amount of space on the user's device. In this episode, we add the ability to limit the size of the cache on disk, similar to how the image service limits the size of the cache in memory.

in Networking

Asynchronously Reading Data from Disk

Image Caching in Swift

The previous episodes have illustrated that caching images can result in significant performance improvements. In the previous episode, I stressed the importance of writing cached images to disk on a background thread to prevent the image service from blocking the main thread.

in Networking

Caching Images on Disk

Image Caching in Swift

In this episode, we continue to improve the solution we implemented in this series by caching images on disk. Caching images on disk has a number of benefits. It reduces the number of requests the application makes and it improves the performance of the application. The user experiences the application as fast and snappy.

in Networking

Caching Images in Memory

Image Caching in Swift

We added the ability to cancel image requests in the previous episode. This and the next episode focus on caching images. We start simple by caching images in memory.

in Networking

Cancelling Image Requests

Image Caching in Swift

Most applications display images in some way, shape, or form. Those images are often fetched from a remote server, introducing a number of interesting challenges. Performing a request to a remote server takes time and it requires resources. It is therefore important to consider solutions to minimize the number of requests an application makes.

in Networking

Failable Initializers

Swift Patterns

If you are new to Swift, then you may be wondering what a failable initializer is and why you would ever use one. In this episode, I show you how to create a failable initializer and I hope I can convince you of their benefits. I use failable initializers in every project I work on and you may be surprised when I say that you do too.

in Patterns