How can you improve React code reusability with declarative programming?

In my experience, functional components in React offer a concise and straightforward approach to building UI elements. Operating as pure functions, they reduce boilerplate code and enhance readability. Their modular nature facilitates collaboration and code maintenance. Avoiding state, lifecycle methods, and the this keyword simplifies the codebase, making it accessible for developers new to React. The introduction of hooks adds flexibility without sacrificing the declarative nature of functional components, streamlining development and improving code organization. Overall, functional components have transformed my development experience, providing cleaner, more maintainable code for modern React applications.

Ever since React 16.8.0 was introduced, functional components brought absolute wonders to the React ecosystem as previously the class-based components had a lot of boilerplate code and lifecycle methods to follow and there were no Hooks previously that could make stateless FC stateful. So combining FC with React hooks, it all became simplified, concise, clear, and managing state and side effects became much easier than before. 'useEffect' replaces 3 component lifecycle methods: i. componentDidMount ii. componentDidUpdate iii. componentWillUnmount Isn't it amazing? FC are easier to reuse and also test. They perform better as there is no need for instances, no binding of 'this', offer easier code splitting, etc.

After React 16.8 launched in February 2019, React Hooks was introduced & now functional components can also have states (using useState) & manage life cycle options (using useEffect) and that's why the ReactJs library developer recommends using functional components. It's very lightweight & makes the code more readable & efficient.

I preferred functional components in React. They're just cleaner and more straightforward – you get props, return JSX, and that's it. No dealing with 'this' keyword or lifecycle methods. They're super easy to reuse and test, especially with less boilerplate to worry about. Plus, with hooks, you can still do everything you need without losing that neat, declarative feel. For me, it's all about keeping things simple and functional components do just that.

Improve React code reusability: Functional components: Prefer functional over class components. Custom hooks: Abstract shared logic into reusable custom hooks. Higher-order components: Create reusable HOCs for shared logic. Render props: Pass functions as props for dynamic behavior. JSX expressions: Enhance reusability with concise JSX expressions. Context API: Centralize state management for easy sharing. Consider: Component composition, separation of concerns, thoughtful props API design, and comprehensive documentation for effective code reuse.

The general rules of React Hooks also apply to custom Hooks; these include: 1)Only call Hooks at the top level. Don’t call Hooks inside loops, conditions, or nested functions. 2)Only call Hooks from React function components. 3)Don’t call Hooks from regular JavaScript functions. In a scenario where we would want to implement the logic for both the useState and useEffect Hooks across different components, using custom Hooks is an efficient solution. Custom Hooks produce a clean and structured codebase that reduces complexity and redundancy in your React project.

Custom hooks have so many use case, some of them which are very common are, - Authentication & Authorization: Like, we can set the user data & check if user has permission to check particular screen or components are not. - LocalStorage Sync: To make available offline data. - Media Queries: Using window.matchMedia, we can make the very useful Media Query custom hook. - Scroll Position: For listening scroll events & scroll position, we can use it. - Dark Mode Toggle: Check which mode is currently active & to toggle it. - WebSocket/Socket.IO Communication: We can listen the socket events & we can emit the events. - Form State Management: Managing form state is every easy with custom hooks. there are many other use of custom hooks.

Custom hooks are a true reflection of reusability in React. They empower devs to create their own highly efficient, reusable (a custom hook does not need to be rendered over and over again), more readable, and easier to test custom hooks that can be re-used across the whole app for performing the same/similar set of actions. For e.g. fetching data (useFetch), debouncing (useDebounce), setting and clearing a timeout (useTimeout), etc. Isn't it amazing that you a custom hook efficiently once and simply reuse it all across your app without having to re-write the similar set of functions again? Note: Did you know you can replace HOC's with custom hooks? As they are more readable, concise, and don't have the wrapper hell which HOC's offer.

Custom hooks in React are functions that enhance reusability by streamlining code across components. They abstract common patterns like data fetching and state management, promoting cleaner and more efficient React development. This game-changer significantly improves modularity, making it easier to reuse logic in various parts of your application.

So, imagine you're building a cool app, and you keep doing the same tasks over and over again, like fetching data or handling user input. Custom hooks are like shortcuts that let you reuse these tasks in different parts of your app without writing the same code every time. They're super handy because they save you time and make your code cleaner and more organized. Basically, custom hooks help you build awesome apps faster and with less hassle!

Not just for loading, but Higher order components have many use cases like, - Listening to Socket events. - Preventing UnAuthorized users from accessing/viewing pages or components. - Make the template files, like we can keep the header & footer inside the Higher order components & using it in every page's root component makes it easy to include the header & footer on every page. - Making the global state management libraries. currently widely used libraries like Redux, React Recoil, and Zustand are using higher-order components to manage the global state & make the global state accessible at any nested component. there are many other use cases of Higher Order Components.

We cab create higher order components and add shared logic inside it,Then we can wrap it with components and we can reuse it across our application

At Inner Matrix Systems, leveraging higher-order components in React significantly improved our code reusability. By implementing HOCs, we were able to augment existing components with additional features like advanced data handling, all without altering the original component structure. This approach not only streamlined our development process but also highlighted the effectiveness of HOCs in creating more modular, maintainable React applications.

HOCs are useful for reusing code that enhances component behavior, such as error handling, data fetching, or styling. By wrapping components with HOCs, you can extend their functionality without modifying their implementation, promoting code reuse and abstraction.

A very common use case of render props is making Tab bars (all kinds of including the bottom tab bar, for example). on selecting a specific tab the data inside a particular tab will display the component passed for the selected tab. (it known as Conditional rendering) Another very useful example is the Accordion Component. We can also make the slider components using it. Very famous libraries like React Router use it very in-depth, we just need to pass the path & page components to show the page based on the current URL.

This approach allows you to create components that are highly reusable and customizable, as the rendering logic can be passed around and shared among various components. It's particularly useful when you need to share UI logic without creating a tight coupling between components.

In the beginning of ReactJS, we was required to use React.createClass function which requires propTypes, getDefaultProps() & render() as argument. After ES6, JSX syntax was introduced. Using the JSX syntax, our code looks more readable & gives HTML feeling. ReactJs library developer also recommends now to use JSX syntax instead of using pure functions.

By utilizing JSX, you can create and reuse UI fragments across your application, enhancing readability and maintainability. JSX promotes the declarative approach by letting you describe your UI structure in a way that resembles the output, making it easier to develop and reuse complex UIs.

1. Selecting State Management Approach: In a majority of projects, the Context API suffices for managing the state instead of using state management libraries like Redux or MobX. 2. Structured Provider Strategy: Organize providers by features for clarity and maintainability. 3. Discernment in Global State Usage: Be selective with global context to ensure app architecture is flexible. 4. Data Fetching and Contextual Rendering: Divide data fetching (context) and rendering responsibility (components). 5. Handling Ubiquitous UI Components: For UI components that are pervasive throughout your application, such as input fields or tables, prop drilling can sometimes be more straightforward

By using Context, you can avoid prop drilling and make your components more reusable, as they can consume context values directly without relying on prop chains. This is particularly useful for themes, user settings, or any global data that needs to be accessible by many components.

Understanding Common Terms Associated to React JS: - Virtual Dom: It is a programming concept where an ideal, or “virtual”, representation of a UI is kept in memory and synced with the “real” DOM by a library such as ReactDOM. - JSX: JavaScript extension, or more often JSX, is an extension of React that helps us to write HTML-like JavaScript. - Elements: Describes what you want to see on the screen. - Components: They are independent and reusable bits of code. They return HTML with a render function. - Props: Stands for properties and is used to transfer data from one component to another. - States: An object that represents the parts of the app that can change. - Transpiler: A compiler that transforms one type of syntax into another.