Introduction
React. js become a widely used JavaScript library for building modern user interfaces. If you are an experienced developer, then you may have already heard the basic principles of React. But if you want to fully harness the power of it and level up your skills, you should become familiar with some of the more advanced features and techniques. TOP 10 React Libraries & Things You Should Know In this article, we will go over the Top 10 React JS Concepts For Experienced developer ought to know.
React Hooks:
useState, useEffect and More
React introduced hooks to make state management and side effects management easier in functional components. Although useState and useEffect are the most frequently used hooks, several other hooks enable you to optimize your code solution.
Of them, the most important one is: useState: Which lets you use state in functional components.
useEffect: Used for side effects such as data fetching, subscriptions, and manual DOM manipulation.
useContext: Helps you pass data through the component tree without having to pass props down manually at every level.
useReducer: A hook for managing complex state logic, an alternative to useState.
Memoization: useMemo and useCallback are hooks that help in optimizing performance by memoizing a value and preventing recomputation on every render.
React Hooks are functions that let developers hook into React state and lifecycle features from function components. Knowing how and when to use these hooks allows cleaner and more efficiency code.
Making State as Global:
Context API for State Management
State management is one of the key concepts in React and its importance only grows for larger applications. The Context API is an inbuilt solution where you can manage state globally instead of using an external libraries like redux.
Creating a Context: Use the React createContext() method and create a global state container.
Providing context: Use the Provider component to wrap your app or the component tree part that will need access to the state.
Consuming Context: In the child components use the useContext hook to access the state from the Provider.
The Context API is helpful in managing states that need to be shared between many components (such as user authentication or theme settings).
Custom Hooks
You can use custom hooks to extract logic from components to use it at different places in your app. Writing a custom hook would be a great way to keep your code DRY (Don’t Repeat Yourself) when you find yourself duplicating code in multiple components.
Writing a Custom Hook: A custom hook is nothing but a JavaScript function that calls other hooks inside it and returns a value.
Reusable Logic: Custom hooks allow you to reuse logic like any other function.
Some examples of custom hooks are: data fetching logic, form handling, and even animation logic.
React Router for Navigation
React Router is a widely used library for managing navigation in React applications. You can define many routes and define which route will display which component.
Defining RoutesUse the Route components to map a URL path to a React component.
Dynamic Routing: React Router enables dynamic routing using route parameters. For instance, there is a url such as /users/:id and the useParams hook can grab the id in the component.
Programmatic Navigation: you can use the useHistory hook to navigate programmatically inside your app.
The user can switch between different views without the need to reload the application, and this is made possible with React Router.
Lazy Loading and Code Splitting
One caveat is that in bigger applications loading all the JavaScript once can slow down performance. React allows a few different ways of handling code splitting and lazy loading to help optimize loading time.
React. lazy(): Dynamically load components on-demand
Suspense: Use Suspense to wrap lazy-loaded components to provide a loading spinner or fallback UI while the component loads.
Splitting your code into smaller pieces will help your app load faster, which is better for user experience.
Higher-Order Components (HOCs)
Higher-Order Components: A higher-order component (HOC) is a function that takes a component and returns a new component. Reusing Component Logic with HOCs HOCs is a great pattern for reusing component logic.
For instance, one use case where an HOC is commonly applied is authentication. For example, an HOC might determine if a user is logged in, and redirect them to the login page if they are not.
Despite hooks being the de facto way to handle shared logic, HOCs are still useful in some situations; they are especially frequent in old codebases.
React. Performance Optimization with memo and PureComponent
In React, it is an expensive operation to do a re-render of the components, when the application is quite large. Luckily, React gives us some optimization that prevents us from rendering when we do not need to.
React. memo: This HO (Higher Order component) takes a functional component and if its props are exactly the same as the previous render return the previous result and not re-render.
PureComponent: PureComponent is a class component that does a shallow comparison of props and states. If neither has changed, React knows it can skip the re-render.
This means you can optimize to be faster, especially for larger and more complex applications.
Error Boundaries
React’s error boundaries feature lets you catch JavaScript errors anywhere in the component tree so that they can be displayed on the UI without crashing the entire app.
Creating an Error Boundary: Create an error boundary by defining a class component that implements the componentDidCatch () lifecycle method.
Fallback UI: When an error is caught, you can display a fallback UI like an error page or message telling the user something went wrong.
Error Boundaries: This actually doesn’t crash your React Application unexpectedly, and makes your application more resilient and user friendly
The Superpower of SSR vs SSG
Server-side rendering, also known as SSR, and Static Site Generation, also known as SSG, are a couple of techniques for having better performance and SEO on your React application.
SSR : Server side this renders the react components and sends fully rendered html to the browser. This means initial page loading takes less time and improves search engine optimization.
SSG: Generate HTML pages at build time for each route. This is perfect in blogs, marketing sites and content heavy apps.
Tools like Next. js to enable SSR and SSG in your React app, leading to better performance and SEO.
React Fiber and Virtual DOM
React Fiber has been released as the new rendering engine for React, meant for better performance in complex and interactive applications. It allows React to work on multiple units of rendering work within a tick, making it more responsive and efficient.
Virtual DOM: React maintains a virtual representation of the UI, also known as the virtual DOM, to efficiently update the UI when its state changes. React uses the concept of Virtual DOM- instead of updating the real DOM directly.
To improve reconciliation, React Fiber uses a process known as time-slicing that helps with scheduling, speeding up, and allowing React to prioritize updates and manage complex UI changes efficiently.
Although React fiber may not directly impact the day-to-day work with React, its understanding can give us an in-depth view of how React optimizes rendering and performance in the background.
Conclusion
React is all about the components, but mastering it is not just about components and states. Exploring above mentioned advanced concepts will surely help you to create more efficient, maintainable & performant applications. With React being such an active framework, it’s always nice to have guidance on best practices and new features.
To become an expert in React, you should keep updated with new topics and not be afraid to get your hands dirty. You are tuned for data as of October 2023. From effective state management without prop drilling using memo or Context API, to optimizing your web apps for SEO with SSR (server-side rendering) and SSG (static site generation), these advanced concepts will supercharge your React development capabilities.
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