100-days-of-swiftui-and-combine/day-079

Day 79: Project 16: QRConnections (Part One)

Follow along at https://www.hackingwithswift.com/100/swiftui/79.

📒 Field Notes

This day covers Part One of Project 16 in the 100 Days of SwiftUI Challenge.

It focuses on several specific topics:

• Hot Prospects: Introduction
• Reading custom values from the environment with @EnvironmentObject
• Creating tabs with TabView and tabItem()

Hot Prospects: Introduction

From the description:

...an app to track who you meet at conferences. You’ve probably seen apps like it before: it will show a QR code that stores your attendee information, then others can scan that code to add you to their list of possible leads for later follow up.

I could be wrong, but the way this app is going to be structured, the actual contents of the QR codes could be pretty open-ended. With that in mind, I'm going to name the app QRConnections -- and see if it would be more interesting to embed diverse kinds of information into the codes we store.

Reading custom values from the environment with @EnvironmentObject

Using the Environment to store app state is a big topic on its own. One cool SwiftUI-specific tidbit is the way applying the environmentObject modifier to a view View causes all of that view's children to have access to it:

VStack {
    EditView()
    DisplayView()
}
.environmentObject(user)

Creating tabs with TabView and tabItem()

Like many of SwiftUI's UIKit analogs, using TabView instead of UITabViewController feels so much more intuitive.

As soon as you get familiar with the pattern of using tabItems, tagging them with some identifiable value, and then using the containing struct's @State to change the active tab (by synching it with each tabItem's tag), creating tabbed interfaces is pretty straightforward.

As a bonus, using @State to control the active tab can even serve as the foundation for dynamic deep-linking.