swiftui-environment

What problem does it solve?

SwiftUI data flow often requires prop drilling or boilerplate to share values across views. Environment provides downward data propagation, while Preferences allow child-to-ancestor communication of measurements and state for responsive UI behavior.

Core Features & Use Cases

• Define EnvironmentKey and extend EnvironmentValues to introduce shared values (e.g., theme, services) accessible across the view tree.
• Read values with @Environment and inject them via .environment() to enable dependency injection without explicit initializers.
• Use PreferenceKey and related modifiers such as .onPreferenceChange and .overlayPreferenceValue to propagate measurements and state upward through the hierarchy.

Quick Start

Define a custom EnvironmentKey, extend EnvironmentValues, inject it via .environment, and read it with @Environment in a sample view.