RxSwift vs Combine: what’s better?

In a few words, a framework is a set of tools for accelerated development, aimed at solving specific problems. A framework consists of many different libraries that facilitate the development of an app or website. Depending on the framework used, you get a certain set of features for your app.

Combine is a new-brand framework and RxSwift is a pretty old one, but even this “age” difference doesn’t matter in their competition for developers’ hearts. So, what are their main advantages and disadvantages, and what to choose for your app?

What are Combine framework's advantages and disadvantages?

Combine is a new framework that Apple introduced at WWDC 2019. This framework implements a declarative Swift API for handling values over time. Combine bears similarities to such frameworks as RxSwift and ReactiveSwift. Thanks to it, you can create functional reactive code by providing a declarative Swift API.

Pros:

1. It works using asynchronous code. This allows the application to run more efficiently, safer and makes it easier to test the final product.

2. It was created with all the rules for optimizing performance. As a result, you get a higher speed of work without additional actions.

3. It supports back-pressure out of the box. It significantly reduces the time it takes to detect errors in the code.

4. It concentrates on the core elements of reactive programming. This effectively weeds out operators and components that you rarely use.

Cons:

1. It offers quite sophisticated error handling functionality. You must make sure to manage errors on your own.

2. It does not offer backward compatibility. Combine requires iOS 13 / macOS Catalina and its new run time.

What are RxSwift framework's advantages and disadvantages?

RXSwift was created two years after the release of Swift, and immediately took the top positions in the app development niche. One of its main advantages is its multiplatformity, which gives it versatility in use. In addition, RXSwift greatly simplifies and offloads asynchronous code in Swift, which is much appreciated by developers.

Pros:

1. It is multi-platform. That is, it is able to create a common interface for the model level API between iOS and Android. This significantly saves QA specialists time.

2. It allows you to simplify your code through asynchrony and simplified declarative code. This makes the code easier to read and easier to analyze for errors.

3. It includes components. This makes it easier to structure and organize your components with others.

Cons:

1. It is quite difficult to learn and apply. This fact makes it difficult to attract new specialists to the ongoing project, especially at later stages.

2. It has complex debugging data transformation. This means that if a problem arises, you will run into the confusion of methods in your code, and the search for a solution will drag on.

3. It is spreading throughout the entire codebase. Interaction entry and exit points Rx interact with UIKit are awkward and difficult to analyze.

Conclusions

In summary, the Combine and RxSwift have many characteristics in common. In particular, both frameworks enable reactive programming on Apple devices.

Among the main differences is Combine's lack of backward compatibility, which can keep audiences using RxSwift. But it should be borne in mind that over time, users will switch to new versions of iOS, which means that the popularity of Combine can increase dramatically many times over.