Combine Framework

Reactive programming with Apple's Combine framework.

See also: Combine is the legacy reactive stack. For new SwiftUI state, prefer the Observation framework (@Observable) — see the swiftui-observation skill. Reach for Combine for existing ObservableObject/@Published code, custom publisher pipelines, and event streams.

Core Concepts

Publisher & Subscriber

// ✅ Basic subscription
let publisher = Just("Hello")
let cancellable = publisher.sink { value in
    print(value)  // "Hello"
}  // sink returns AnyCancellable, not a Subscriber

Creating Publishers