Separating presentation from content with ViewBuilder

ViewBuilder is a custom parameter attribute that constructs views from closures. ViewBuilder can be used to create custom views that can be used across the application with minimal or no code duplication. We will create a SwiftUI view, BlueCircle.swift, for declaring the ViewBuilder and implement the custom ViewBuilder. The ContentView.swift file will be used to implement the custom view.

Getting ready

Create a new SwiftUI project named ViewBuildersApp.

How to do it…

1. Open the ViewBuildersApp and add a new SwiftUI view to the project from the menu: File | New | File.
2. Select the SwiftUI view from the menu.
3. Click Next.
4. Name the file BlueCircle and click Create.
5. Delete the BlueCircle_Previews: struct from the file (delete all five lines of code).
6. Add BlueCircle ViewModifier to the file:

   struct BlueCircle<Content: View>: View {
       let content: Content
     ...