Technical requirements

The code in this chapter is based on Xcode 15.0 and iOS 17.0. You can download and install the latest version of Xcode from the App Store. You'll also need to be running macOS Ventura 13.5 or newer. Simply search for Xcode in the App Store and select and download the latest version. Launch Xcode and follow any additional installation instructions that your system may prompt you with. Once Xcode has fully launched, you're ready to go.All the code examples for this chapter can be found in the Chapter06 folder of this book's GitHub repository: https://github.com/PacktPublishing/SwiftUI-Cookbook-3rd-Edition/tree/main/Chapter06-Presenting-Views-Modally.

Presenting alerts

A common way of showing important information to the users is by using alerts with a message and some buttons. In this recipe, we will create a simple alert that gets displayed when a button is pressed.The way alerts are presented in iOS 13 and 14 has been deprecated. iOS 15 introduced a new way of presenting alerts. For the sake of being able to handle devices on earlier iOS versions, we'll go over both ways of presenting alerts, starting with iOS 15. The code for iOS 13 and 14 alerts is found in the OldAlerts.swift file while the newer iOS 15 version is in ContentView.swift.

Getting ready

Create a new SwiftUI project called PresentingAlerts.Make sure that the project's iOS Deployment Target is at least iOS 15.0.

How to do it…

We will add a Button or Text to the scene that can be used to display an alert containing a single button. The iOS 15 steps are as follows:

1. Create a @State variable that will be used to trigger the presentation of our Alert...

Adding actions to alert buttons

We may want to display alerts with more than just an OK button to confirm the alert has been read. In some cases, we may wish to present a Yes or No choice to the user. For example, if the user wants to delete an item in a list, we may wish to present an alert that provides the option of whether to proceed with the deletion or cancel the action.In this recipe, we will look at how to add multiple buttons to our alert. We will provide the descriptions for iOS 15 alerts. You can find the code for iOS 13 and 14 alerts in the OlderAlertsWithActions.swift file.

Getting ready

Create a new SwiftUI app called AlertsWithActions.

How to do it…

We will implement an alert with two buttons and an action. The alert will get triggered by a tap gesture on a button. When triggered, the alert displays a message asking the user if they want to change the text currently being displayed. A tap on OK changes the button title, while a tap on Cancel leaves the text unchanged...

Presenting confirmation dialogs

SwiftUI confirmation dialogs and alerts are both used to request additional information from the user by interrupting the normal flow of the app to display a message. Confirmation dialogs give the user some additional choices related to an action that they are currently taking, whereas the Alerts view informs the user if something unexpected happens or they are about to perform an irreversible action.Confirmation dialogs were introduced in iOS 15. The similar but deprecated functionality in iOS 13 and 14 is called ActionSheet. The implementation for ActionSheet is located in the oldActionSheets.swift file.In this recipe, we will create a confirmation dialog that gets displayed when the user taps some text in the view.

Getting ready

Create a new SwiftUI project called PresentingConfirmationDialogs.

How to do it…

We will implement a confirmation dialog by adding the .confirmationDialog(_:isPresented:titleVisibility:actions:) view modifier to a...

Presenting new views using sheets and full-screen covers

Sheets and full-screen covers are another way to present modals in our apps. Sheets are used to present views modally over existing ones while allowing the user to dismiss the sheet by dragging it down. A full-screen cover, or cover for short, is another modal view that takes as much of the screen as possible.In this recipe, we will learn how to present several sheets to the user, how to control the height of a sheet, how to add a navigation bar with a Dismiss button to a sheet, and how to present a full-screen cover.

Getting ready

Create a new SwiftUI project named PresentingSheets.

How to do it…

We will create two SwiftUI views named SheetView and SheetWithNavBar that will be displayed modally when a button is clicked. The steps are as follows:

1. In ContentView.swift, between the struct declaration and the body variable, add three state variables of type Bool. The state variables will be used to trigger the presentation...

Displaying popovers

A popover is a view that can be displayed on screen to provide more information about a particular item. It includes an arrow pointing to the location where it originates from. You can tap on any other screen area to dismiss the popover. Popovers are typically used on larger screens such as on the iPad.In this recipe, we will create and display a popover on an iPad.

Getting ready

Create a new SwiftUI project named DisplayingPopovers.

How to do it…

Following the pattern we've used so far in this chapter, we will first create a @State variable whose value triggers the displaying or hiding of a popover. Then we will add a .popover() modifier that displays the popover when the @State variable is true. The steps are as follows:

1. Just above the body variable in the ContentView.swift file, add a state variable that will be used to trigger the display of the popover:

@State private var showPopover = false

1. Within the body variable, replace the contents with...

Creating context menus

A context menu is a pop-up menu used to display actions that the developer anticipates the user might want to take. SwiftUI context menus are triggered using the touch-and-hold gesture in iOS and iPadOS and a control click on macOS. Context menus consist of a collection of buttons displayed horizontally in an implicit VStack.In this recipe, we will create a context menu to change the color of an SF symbol.

Getting ready

Create a new SwiftUI project named DisplayingContextMenus.

How to do it…

We will display a light bulb in our view and change its color using a context menu. To achieve this, we'll need to create a @State variable to hold the current color of the bulb and change its value within the context menu. The steps are as follows:

1. Just above the body variable in ContentView.swift, add a @State variable to hold the color of the bulb. Initialize it to red:

@State private var bulbColor = Color.red

1. Within the body variable, change the Text...

Programmatically switching tabs on a TabView

In the preceding recipe, we learned how to switch between tabs by tapping on tab items at the bottom of the screen. However, we may also want to programmatically trigger tab switching. In this recipe, we will use a tap gesture to trigger the transition from one tab to another.

Getting ready

Create a new SwiftUI app named TabViewWithGestures.

How to do it…

We will create a TabView with two items, each containing some text that triggers a tab switch on click. The steps are given here:

1. Open the ContentView.swift file, and add a @State variable to hold the value of the currently selected tab:

   struct ContentView: View {
       @State private var selectedTab = 0
   ...
   }
   

2. Replace the Text view in the body variable with a TabView, with two tab items:

       var body: some View {
           TabView(selection: $selectedTab) {
               Text("Left Tab. Tap to switch to right")
        ...