Composable Navigation: Alerts & Dialogs

Brandon: So, we are seeing that if you want integrated features in vanilla SwiftUI in order to reap all the benefits that brings, you still have a number of steps to take to get it right, but in some sense there is even less help from the compiler and runtime to make sure you did everything correctly.

We think everything we have accomplished so far is pretty cool and even impressive, but its real purpose is to dip our toes into composing features together and communicating between features, because that concept is central to the Composable Architecture, and even more so with navigation.

By composing many features together, including all the destinations one can navigate to, we can have a very simple representation of something that is actually quite complex. No matter how many different places you can navigate to from a screen, and no matter how many layers deep you are in a navigation stack, you will have the ability to inspect what is happening in every layer and introduce new logic to integrate everything together. It’s honestly amazing to see.

Stephen: But building those tools takes time, and to get the first hint at what those tools will look like eventually we will turn to one of the simplest forms of navigation: alerts. Alerts have the notion of presenting and dismissing, but they don’t manage logic and behavior on the inside. They simply show some buttons, and the user taps one of them to dismiss and optionally kick off an action.

Let’s start by showing how we can add an alert to this application using the tools that the Composable Architecture already comes with, and in fact these tools have been in the library since basically the beginning. And then we will see how we can greatly improve the tools, and that will set the stage for more complicated forms of navigation, such as sheets, popovers ,and even drill-downs.