Fetching and manipulating our data using model context

Developers familiar with Core Data are also familiar with the idea of context. Context is our data sandbox. This is the place where we can manipulate and fetch data, and it’s the link between our models and the persistent store.

To gain access to our context from our SwiftUI view, we can use an environment variable named modelContext:

struct ContentView: View {
    @Environment(\.modelContext) private var modelContext
}

The modelContext environment variable is available whenever we set up our scene using the modelContainer modifier.

In non-SwiftUI instances, we can access the context using our model container mainContext property:

let modelContext = modelContainer.mainContext

To understand how to work with a model context, we’ll start with the most basic operation, saving new objects for our store.

Saving new objects

At the beginning of this chapter, in the Defining a SwiftData...