ใช้โมเดลร่วมกันผ่าน @Environment

Passing a model through every view in between gets tedious. The environment lets deep child views reach it directly.

The environment is a shared bag of values flowing down the view tree, so any descendant can read what an ancestor placed there.

Place an observable model into the tree with the .environment modifier on a parent view.

A child reads the shared model by declaring a property with the @Environment wrapper and the model type.

The environment finds the model by its type, so the type you inject must match the type a child asks for.

Children no longer need the model handed through every initializer. They simply pull it from the environment when needed.

Once read, the environment model behaves like any other: read its values and call its methods.

Everyone reads the same injected instance, so changes made in one screen show up everywhere that reads it.

Inject the model near the top of the tree, often at the app root, so every screen below can share it.

One view still owns the model with @State and injects it. The environment only shares that single instance downward.

If a child reads a model the environment never received, the app crashes, so always inject before any reader appears.

You shared one model across the view tree using @Environment: inject it high up, then read it by type in any descendant. 🌍