What is Redux?
- Redux is a State management pattern that helps manage application state in a predictable, centralised, and immutable way.
- It’s commonly used in front-end frameworks like React, but it can also be applied in Swift applications using Combine.
Think of Redux like a central control system:
- There is one source of truth (a single state store).
- The only way to change state is through actions (controlled updates).
- The state updates predictably based on dispatched actions.
Redux helps manage global state changes in a predictable way by enforcing a unidirectional data flow.
🔗 Further Reading: Redux Docs
How is Combine Used with Redux in Swift?
- Combine enhances Redux in Swift by making state updates reactive
- Instead of manually updating UI when state changes, Combine automatically propagates changes to subscribers, ensuring that views stay in sync with the state
How Redux and Combine Work Together
1️⃣ State is stored in a single @Published property** inside a Store.
2️⃣ Reducers update the state in response to dispatched actions.
3️⃣ Views subscribe to state changes** using @ObservedObject or @StateObject, ensuring automatic UI updates.
Key Principles of Redux
✔ Single Source of Truth → The entire state of the app is stored in one object.
✔ State is Read-Only → The only way to change state is by dispatching actions.
✔ Pure Functions (Reducers) → State updates are handled by pure functions called reducers.
✔ Unidirectional Data Flow → State flows in one direction, making it predictable.
Reference Diagram (Redux Flow)
1️⃣ View Dispatches an Action 2️⃣ Action Describes What Happened 3️⃣ Reducer Updates the State Based on Action 4️⃣ New State is stored and Used by the View
Key Takeaways
- Redux centralises state management, ensuring a single source of truth.
- Reducers handle state updates predictably through pure functions.
- State is immutable, and the only way to update it is by dispatching actions.
- Swift’s Combine framework works well with Redux for reactive state management.
- Useful for large applications where state needs to be shared across multiple views.