A state management library for JavaScript applications.
Can be used with React, Angular, Vue, or vanilla JavaScript.
Centralizes application state in a single JavaScript object called the store.
Why Use Redux?
Synchronize various parts of a complex UI application.
Prevent issues like infinite loops due to unpredictable data changes.
Inspired by Facebook's Flux architecture for making data flow predictable and transparent.
Popular alternative: MobX.
Stores application state centrally, solving synchronization issues across UI components.
Benefits of Redux
Predictability: Makes state changes predictable and transparent.
Debugging: Easier debugging with tools like Redux Dev Tools (e.g., time-travel debugging).
Optimization: Cache or persist state; efficient data synchronization across UI components.
Compatibility: Works with any library or framework (React, Angular, Ember, Vue, etc.).
Large Ecosystem: Rich and growing ecosystem of add-ons and tools.
Downsides of Redux
Complexity: Introduces additional complexity and boilerplate code.
Verbosity: Traditional Redux code is often verbose.
Not suitable for small to medium-sized apps with simple UIs.
Course Structure
Functional Programming in JavaScript: Higher-order functions, composition, currying, immutability.
Fundamentals of Redux: Reducers, actions, action creators.
Building Redux from Scratch: Understand internal workings by coding out a Redux-like framework.
Debugging Redux Applications: Tools and techniques for effective debugging.
Modern Redux: Writing clean, concise Redux code with less boilerplate.
Designing a Redux Store: Patterns and techniques for complex applications.
Middleware: Simplifying complex operations within Redux (API calls, side effects).
API Calls: Efficient techniques for managing API calls, loading indicators, and caching.
Testing: Best practices for writing effective tests for Redux code.
Integrating with React: Traditional and modern methods for connecting Redux with React components.
Functional Programming
Definition: Decomposing problems into small, reusable functions.
Benefits: Functions are more concise, easier to debug/test, and scalable.
Higher-Order Functions: Functions that take/return other functions (e.g., map, filter, setTimeout).
Function Composition: Combining simpler functions to build complex ones.
Currying: Transforming a function with multiple arguments into a sequence of functions with a single argument each.
Pure Functions: Functions that return the same result given the same inputs and have no side effects.
Immutability: Once data is created, it cannot be modified. Use methods like spread operator or libraries like Immutable.js and Immer to make data immutable.
Immutable.js
Facebook's library for immutable data structures.
Benefits: Provides immutable data structures like Map, List.
Downsides: Learning new API, integration issues with other libraries.
Immer
Developed by the creator of MobX.
Works with plain JavaScript objects; uses produce function to apply mutations without affecting original objects.
Redux Basics
Store: Central repository for the state; singleton pattern.
Actions: Describes what happened; plain JavaScript objects with a type field.
Reducers: Pure functions that take the current state and an action, return the new state.
Dispatch: Method to send actions to the store, triggering state changes via reducers.
Subscribe: Method to listen for state updates and react accordingly.
Setting Up the Store
Create a Reducer: Function to handle state transitions based on actions.
Initial State: Define initial state within the reducer.
Create Store: Use createStore from Redux, passing the reducer.
Dispatching Actions: Use store.dispatch to send actions.
Subscribing to Store: Use store.subscribe to update UI on state changes.
Enhancing Code with Action Creators and Action Types
Action Types: Constants representing action types to avoid typos and improve maintainability.
Action Creators: Functions that return action objects, simplifying action dispatching.
Practical Example: Bug Tracking Application
Actions: Adding, removing, and resolving bugs.
Reducer: Handle the state transformations based on actions.
Dispatch Actions: Add, remove, and resolve bugs through dispatched actions.
Subscribe to Store: Log state changes or update UI components.
Conclusion
Understanding of how Redux centralizes state and makes data flow predictable.
Awareness of actions, reducers, store, and middleware.
Key techniques in functional programming relevant to Redux.
Practical insights by building a bug tracking application.
For more in-depth learning, enroll in the complete course available at codewithmosh.com.