OrchardNest

The API the image service exposes no longer accepts a completion handler. It returns a publisher instead. This is an improvement, but the image service still uses completion handlers under the hood. In this episode, we replace the...

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

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...

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...

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...

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...

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...

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...

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.

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...

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...

Cloudy shows the user an error if it isn't able to fetch weather data from the weather API. We map any errors that are thrown to `WeatherDataError` in the `RootViewModel` class. This solution works fine and it is a fitting implementation...

Even though we successfully used the **Combine** framework to fetch data from the weather API, the implementation is incomplete. We ignored error handling up until now and it is time to take a closer look at errors and how to handle them.

Earlier in this series, you learned that reactive programming can be defined as working with asynchronous streams of data. A network request is an asynchronous operation and that makes reactive programming an excellent match for networking.

The builder pattern isn't a common pattern in Swift and Cocoa development and you don't find it in any of Apple's frameworks. It is one of the [Gang of Four](https://en.wikipedia.org/wiki/Design_Patterns) design patterns and widely used in...

In this episode, we fix the settings view using the **Combine** framework. We no longer rely on the delegation pattern to propagate settings changes. In the [previous...

Earlier in this series, we broke the settings view. The root view controller acts as the delegate of the settings view controller, but nothing happens when the user updates a setting in the settings view. In this and the next episode, we...

In the [previous episode](https://cocoacasts.com/initializer-injection-with-view-controllers-and-storyboards), you learned that it is possible to use initializer injection in combination with storyboards as of iOS 13 and tvOS 13. We didn't...

Storyboards have many benefits, but they also have a number of significant downsides. Not being able to control the initialization of a view controller is one of them, especially if you want to use initializer injection. As of iOS 13 and...

The title of this episode is a bit misleading because the Swift programming language has no support for abstract classes. There are a few workarounds, though. In this episode, we take a look at two alternatives to the abstract class...

Types need to have a unique name. In Objective-C, naming collisions with other libraries and frameworks are avoided by adding a prefix to a type. That is why we use `UIView` instead of `View` and `CGRect` instead of `Rect`.

In 2019, Apple introduced another powerful API alongside the Combine framework, diffable data sources. Diffable data sources make it almost trivial to build performant table and collection views. In this episode, I show you why diffable...

In this and the next episode, we shift focus to the week view controller. Populating the week view requires a different approach. It contains a table view and the week view model manages an array of `WeahterDayData` objects. Even though...

The Combine framework defines a range of operators to combine publishers. Combining publishers is a common pattern in reactive programming. In this episode, we improve the efficiency of the `RootViewModel` class by combining multiple...

We ran into several issues in the [previous episode](https://cocoacasts.com/building-reactive-applications-with-combine-reducing-complexity-and-code-duplication). The `assign(to:on)` and `sink(receiveValue:)` methods are convenient, but...

In this episode, we optimize the implementation of the day view controller and the day view model. There are a few details we need to take care of. First, the day view controller should display an error message when its view model emits an...

There are a few user interface issues we need to address in this episode. The day view controller no longer shows its activity indicator view while it is waiting for weather data and the user interface elements that show the weather data...

There are a few user interface issues we need to address in this episode. The day view controller no longer shows its activity indicator view while it is waiting for weather data and the user interface elements that show the weather data...

In the [previous episode](https://cocoacasts.com/building-reacting-applications-with-combine-hiding-implementation-details-with-type-erasure), we put the foundation in place to reactify the `DayViewController` class. In this episode, you...

In the [previous episode](https://cocoacasts.com/building-reactive-applications-with-combine-hiding-implementation-details-with-type-erasure), we put the foundation in place to reactify the `DayViewController` class. In this episode, you...

The root view controller displays the weather data the publisher emits. Every time the publisher emits weather data, the child view controllers of the root view controller receive the weather data and display it to the user. This works...

The root view controller displays the weather data the publisher emits. Every time the publisher emits weather data, the child view controllers of the root view controller receive the weather data and display it to the user. This works...