Learn what’s in store for you as you build Your Second iOS and SwiftUI App. This course builds on the Your First App, and Programming in Swift courses…

Step 1, we’re going to create that dictionary I mentioned earlier to store our book images. We’re going to be using SwiftUI’s Image type for that. So, in Library.swift, import SwiftUI at the top. import SwiftUI And then add a new images variable - a dictionary that uses…

…talked about earlier. Title and Author? Both constants and strings. let title: String let author: String It’s going to be helpful for our SwiftUI previews to be able to give books default values for those properties, but we don’t necessarily need them hardcoded into the type here. Instead…

Review how to add SF Symbols in SwiftUI, and dynamically add an SF Symbol based on a book’s title…

…review some of what you’ve accomplished along the journey of creating Your Second iOS and SwiftUI App. There’s a new learning path in store for you, next…

SwiftUI List View is the backbone of the app you’re going to be creating the UI for in this course. Before we get into Xcode, let’s take a high-level look at what a List is, and how it works. A List is a special type of view…

Combine makes it easy to take an object, observe changes to its properties, and react to those changes, in SwiftUI…

…able to do with lists already, and get a couple of ideas for what you can start thinking about in order to apply SwiftUI Lists in the future…

…library has any sorted books for it. var body: some View { if let books = library.sortedBooks[section] { } } When there are books, we’ll use SwiftUI’s Section view. Any because we’ve got our own “Section” type, you’ll need to disambiguate using the framework name. if let books = library.sortedBooks[section…

Book] { booksCache } func addNewBook(_ book: Book, image: UIImage?) { And as you’ve seen with Book , when you change a struct to a class, in SwiftUI, you very likely should make it an Observable Object, too. class Library: ObservableObject { The properties that you mutate are again, very likely , going to need…

…this episode, let’s just get some basics hooked up and aim for this: We’ll call this the DetailView , and create a new SwiftUI file for it, at the bottom of the Views group. Whenever I start a new file, I select all with command-A and then…

Book Images currently only display symbols. That’s all we’ve told them to do so far! So, let’s supply them with optional SwiftUI Images. You can call the constant image . struct Image: View { let image: SwiftUI.Image? let title: String We’ve got errors now because the struct…

…book, so we’ll need it to be var , not let . 🟩var🟩 book: Book But as you see, the toggling is still not possible. SwiftUI offers multiple solutions to this problem, such as using State , and Binding , which work with value types, like Book is. But we’re going…

Welcome to the final part of Your Second iOS and SwiftUI App! You’ve got a prettier, more custom-looking app, now. But we have some features left to implement. We still need to be able to add and remove books from our library, reorganize them, and sort them into…

ObjectWillChangePublisher powers ObservedObject and EnvironmentObjects in SwiftUI. Use it to propagate ObservableObject changes to collections…

MENU_TOKEN@*//*@PLACEHOLDER=Code@*/ /*@END_MENU_TOKEN@*/ }) .labelStyle... } You don’t need this “perform” here; you can use trailing closure syntax as usual in SwiftUI. BookRow(book: $0) } .onDelete { indexSet in } } So, what is this indexSet that onDelete gives us? In theory, onDelete could be providing you multiple integers…

…here because I’m using it in more than one place in the project. It doesn’t belong in ContentView anymore. import SwiftUI struct TitleAndAuthorStack: View { let book: Book var body: some View { VStack(alignment: .leading) { Text(book.title) .font(.title2) Text(book.author) .font(.title3) .foregroundColor(.secondary) } .lineLimit(1) } } extension Book…

…environment objects are a really nice SwiftUI feature, for keeping the code that connects views as simple as possible. But the environment is not just a place for model objects! An environment is a storage container for potentially any information that multiple views need to function. One piece of potentially…

…over the auto-generated code in the new file. I also needed to move the PHPicker import. /// THE SOFTWARE. import class PhotosUI.PHPickerViewController import SwiftUI And to get a preview going, I used a default book and nil image binding. ReviewAndImageStack(book: .init(), image: .constant(nil) That looked better with some…