Working with the brand new NavigationStack in SwiftUI

In iOS growth, navigation view is unquestionably one of the vital generally used parts. When SwiftUI was first launched, it got here with a view referred to as NavigationView for builders to construct navigation-based person interfaces. With the discharge of iOS 16, Apple has deprecated the previous navigation view and launched a brand new view generally known as NavigationStack to current a stack of views. Most significantly, builders could make use of this new view to construct knowledge pushed navigation.

The Previous Method of Navigation Views

Previous to iOS 16, you create a navigation interface utilizing NavigationView and NavigationLink like this:

This creates a fundamental navigation based mostly interface with a Faucet me button. When tapped, the app navigates one degree all the way down to show the vacation spot view.

Working with NavigationStack

Ranging from iOS 16, you change NavigationView with the brand new NavigationStack. You’ll be able to preserve the NavigationLink intact and obtain the identical consequence.

The identical piece of the code can be written like this:

We often use navigation views to construct a master-detail movement for an inventory of knowledge objects. Right here is an instance:

This creates a navigation view to show an inventory of coloration objects. When an merchandise is chosen, the app navigates to the element view and exhibits the colour view.

Worth-based Navigation Hyperlinks

NavigationStack introduces a brand new modifier referred to as navigationDestination that associates a vacation spot view with a offered knowledge kind. The identical piece of code within the earlier part may be rewritten like this:

You continue to use NavigationLinks to current the listing of knowledge and implement the navigation characteristic. What’s distinction is that every NavigationLink associates with a price. On prime of that, we added the brand new navigationDestination modifier to seize the worth change. When a person selects a specific hyperlink, the navigationDestination modifier presents the corresponding vacation spot view for navigation hyperlinks that current knowledge of kind Colour.

In case you take a look at the app within the preview, it really works precisely the identical as earlier than. Nevertheless, the interior implementation already makes use of the brand new navigationDestination modifier.

A number of Navigation Vacation spot Modifiers

You’re allowed to outline multiple navigationDestination modifier for dealing with several types of the navigation hyperlinks. Within the earlier instance, we had a single navigationDestination modifier for the Colour kind. Let’s say, we’ve one other set of navigation hyperlinks for the String kind like this:

The systemImages variable shops an array of the system picture names.

On this case, we’ve two varieties of navigation hyperlinks. One is for the Colour kind, the opposite is the String kind. To deal with the navigation of the String kind, we will embed one other navigationDestination modifier to the stack like this:

Now if the person faucets one of many system picture names, it navigates to a different view that shows the system picture.

Working with Navigation States

In contrast to the previous NavigationView, the brand new NavigationStack means that you can simply preserve observe of the navigation state. The NavigationStack view has one other initialization technique that takes in a path parameter, which is a binding to the navigation state for the stack:

If you wish to retailer or handle the navigation state, you’ll be able to create a state variable. Here’s a code pattern:

The code is just like the earlier instance. We added a state variable named path, which is an array of Colour, to retailer the navigation state. In the course of the initialization of NavigationStack, we cross its binding for managing the stack. The worth of the path variable can be robotically up to date when the navigation stack’s state modifications.

I made a minor change for the navigation vacation spot. It shows the person’s chosen colours and exhibits one other listing of colours for additional choice.

Within the code above, we’ve this line of code to show the trail content material:

The rely property offers you the variety of ranges of the stack, whereas the outline presents the present coloration. Say, for instance, you first choose the colour indigo after which additional selects yellow. The worth of rely is 2, which suggests the navigation stack has two ranges.

With this path variable, you’ll be able to programmatically management the navigation of the stack. Let’s say, we will add a button for customers to leap on to the foundation degree of the stack. Right here is the pattern code:

By resetting the worth of the path variable, we will instruct the navigation stack to return to the foundation degree.

As you might already conscious, we will manipulate the worth of the path variable to regulate the state of the navigation stack. For instance, when the ContentView seems, the app can robotically navigate down three ranges by including three colours to the path variable like this:

If you launch the app, it robotically navigates down three ranges. That is how one can management the navigation state programmatically and an effective way to deal with deep linking.

Abstract

The brand new NavigationStack, launched in iOS 16, permits builders to simply construct data-driven navigation UI. In case your app doesn’t must help older variations of iOS, you’ll be able to reap the benefits of this new part to deal with deep linking and sophisticated person flows.