Why ReactiveReSwift?

Model-View-Controller (MVC) is not a holistic application architecture. Typical Cocoa apps defer a lot of complexity to controllers since MVC doesn’t offer other solutions for state management, one of the most complex issues in app development.

Apps built upon MVC often end up with a lot of complexity around state management and propagation. We need to use callbacks, delegations, Key-Value-Observation and notifications to pass information around in our apps and to ensure that all the relevant views have the latest state.

This approach involves a lot of manual steps and is thus error prone and doesn’t scale well in complex code bases.

It also leads to code that is difficult to understand at a glance, since dependencies can be hidden deep inside of view controllers. Lastly, you mostly end up with inconsistent code, where each developer uses the state propagation procedure they personally prefer. You can circumvent this issue by style guides and code reviews but you cannot automatically verify the adherence to these guidelines.

ReactiveReSwift attempts to solve these problem by placing strong constraints on the way applications can be written. This reduces the room for programmer error and leads to applications that can be easily understood - by inspecting the application state data structure, the actions and the reducers.

Why Reactive?

A common design pattern with Redux and its derivates is to observe your store using functional reactive programming (FRP), which the user takes care of using very similar looking boilerplate, regardless of the FRP library they’ve chosen.

Instead of pushing that onto the user, and to encourage people to use FRP, ReactiveReSwift provides protocols to conform to so that the underlying Store can directly use the observables from your preferred library without subclassing.

ReactiveReSwift also comes with an extremely simple implementation of a functional reactive observable. This ObservableProperty type allows you to use ReactiveReSwift without any other FRP libraries and not lose any of the functionality provided by ReSwift. That said, we do still highly encourage you to use a functional reactive library with ReactiveReSwift.