React JS
React is a JavaScript library primarily used for building user interfaces in single-page applications. While it's often integrated with tools like Webpack for bundling JavaScript and CSS files, React itself does not directly incorporate Webpack. Despite its nature as a library rather than a full framework or programming language, React remains instrumental in modern web development.
React offers various extensions for entire application architectural support, such as Flux and React Native, beyond mere UI.
Why React?
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Declarative Nature: React's declarative approach allows developers to describe the desired UI state, and React handles the rendering efficiently. This simplifies the development process by abstracting away the manual DOM manipulation.
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Improved Performance: React uses Virtual DOM, a lightweight representation of the actual DOM. By comparing the previous and current states of this Virtual DOM, React determines the minimal set of DOM operations needed to update the UI, resulting in faster rendering and better performance.
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Unidirectional Data Flow: In React, data flows in a unidirectional manner, typically from parent to child components. This ensures that any change in the parent component automatically propagates to its child components, simplifying the understanding of data changes and making it easier to trace errors.
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Reusable Components: React promotes the creation of reusable UI components. Each component encapsulates its own logic and UI, allowing developers to compose complex UIs from simpler components. This modularity not only improves code organization but also accelerates development time.
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Versatility: React's versatility extends beyond web development to mobile app development with React Native. This framework leverages React's component-based architecture to build native mobile apps using JavaScript and React principles.
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Developer Tools: React is supported by dedicated developer tools like the React Developer Tools extension for Chrome. These tools facilitate debugging by providing insights into component hierarchies, state changes, and performance optimizations.
ReactJS History
When compared to other technologies on the market, React is a new technology. React was created by Jordan Walke, a software engineer at Facebook, in 2011.Initially implemented in Facebook's News Feed, its success quickly led to its adoption in Instagram, showcasing its power and versatility in building dynamic user interfaces.
React Features
Currently, ReactJS gaining quick popularity as the best JavaScript framework among web developers. It is playing an essential role in the front-end ecosystem. The important features of ReactJS are as following.
JSX
JSX is a syntax extension for JavaScript that allows developers to write HTML-like code within JavaScript. This makes it easier to create and understand the structure of React components, as it closely resembles the final output in the browser. While not mandatory, using JSX is recommended in React development because it enhances readability and simplifies the creation of user interfaces.
Components
React components enable reusability and encapsulation by breaking down UIs into self-contained pieces with their own structure, style, and behavior. This promotes code reuse, as components can be used across different parts of the application, enhancing maintainability and reducing bugs, while ensuring a clean separation of concerns.
One-way Data Binding
One-way data binding is a pattern where data flows in a single direction, typically from the model to the view. This ensures that the state of an application is predictable and easier to manage. In the context of JavaScript frameworks, Flux and Redux are popular architectures that facilitate one-way data binding and state management.
Flux
Flux is an architecture pattern created by Facebook for building client-side web applications. It emphasizes unidirectional data flow and is composed of four key components:
Action:
- Actions are plain JavaScript objects or functions that contain the type of event and any associated data (payload). Actions are the only source of information for the store.
Dispatcher:
- The dispatcher is a central hub that manages all the data flow in a Flux application. When an action is created, it is dispatched to all stores that have registered with the dispatcher. The dispatcher’s role is to handle these actions and ensure they reach the appropriate store.
Store:
- Stores hold the application state and logic. They listen for actions from the dispatcher and update their state accordingly. Stores then emit a change event to notify the view layer to re-render. Each store manages a specific portion of the application's state.
View:
- The view is the presentation layer, typically composed of React components. Views listen to changes from the stores and re-render themselves accordingly. They can also generate new actions based on user interactions and send them to the dispatcher.
Virtual DOM
A virtual DOM object is a representation of the original DOM object. It works like a one-way data binding. Whenever any modifications happen in the web application, the entire UI is re-rendered in virtual DOM representation. Then it checks the difference between the previous DOM representation and new DOM. Once it has done, the real DOM will update only the things that have actually changed. This makes the application faster, and there is no wastage of memory.
Simplicity
ReactJS uses JSX file which makes the application simple and to code as well as understand. We know that ReactJS is a component-based approach which makes the code reusable as your need. This makes it simple to use and learn.
Performance
ReactJS is known to be a great performer. This feature makes it much better than other frameworks out there today. The reason behind this is that it manages a virtual DOM. The DOM is a cross-platform and programming API which deals with HTML, XML or XHTML. The DOM exists entirely in memory. Due to this, when we create a component, we did not write directly to the DOM. Instead, we are writing virtual components that will turn into the DOM leading to smoother and faster performance.
React Ecosystem
The React ecosystem is vast and diverse, encompassing a wide range of libraries and tools that enhance and extend the capabilities of React. These tools help in state management, routing, form handling, styling, and more, making React a robust framework for building complex and feature-rich applications. Here are some of the most popular libraries and tools commonly used with React:
State Management
Redux
Description: Redux is a state management library that provides a predictable state container for JavaScript apps. It helps manage application state and enables powerful debugging capabilities through tools like the Redux DevTools.
Key Features: Centralized state, immutability, middleware support.
MobX
Description: MobX is a simple, scalable, and battle-tested state management solution. It uses observable data to efficiently react to state changes and update the UI.
Key Features: Observable state, actions, reactions, computed values.
Recoil
Description: Recoil is a state management library for React developed by Facebook. It provides a set of utilities to manage state in a React application with minimal boilerplate.
Key Features: Atoms, selectors, asynchronous state management.
Routing
React Router
Description: React Router is the most widely used routing library for React. It allows for dynamic routing in a web application, enabling navigation between different components and views.
Key Features: Nested routes, dynamic routing, query parameters.
Form Handling
Formik
Description: Formik is a library that simplifies form management in React applications. It helps with form validation, error handling, and form submission.
Key Features: Form state management, validation schema support, easy integration with validation libraries like Yup.
React Hook Form
Description: React Hook Form is a performant, flexible library for managing forms in React. It leverages React hooks for form state and validation, minimizing re-renders and improving performance.
Key Features: Minimal re-renders, easy integration with UI libraries, built-in validation support.
Styling
Styled Components
Description: Styled Components is a library for styling React applications using tagged template literals. It allows for writing actual CSS to style components, keeping styles scoped and maintaining a clean component structure.
Key Features: Scoped styling, theme support, dynamic styling.
Emotion
Description: Emotion is a flexible and powerful library for writing CSS styles with JavaScript. It provides both a styled component API and a CSS-in-JS approach.
Key Features: Performant styles, server-side rendering, powerful theming capabilities.
Testing
Jest
Description: Jest is a JavaScript testing framework developed by Facebook, designed to ensure correctness of any JavaScript codebase. It works seamlessly with React, providing a simple and efficient way to test components and applications.
Key Features: Snapshot testing, coverage reports, mocking capabilities.
React Testing Library
Description: React Testing Library is a testing utility that encourages testing best practices by focusing on user interactions and component behavior rather than implementation details.
Key Features: Lightweight, integrates with Jest, emphasizes testing UI from the user’s perspective.
Build and Tooling
Create React App
Description: Create React App (CRA) is a CLI tool that sets up a new React project with a sensible default configuration. It handles configuration for tools like Webpack, Babel, ESLint, and more.
Key Features: Zero configuration, fast setup, extensibility.
Next.js
Description: Next.js is a React framework that enables server-side rendering and static site generation for React applications. It simplifies the process of building complex React applications with features like API routes, file-based routing, and automatic code splitting.
Key Features: Server-side rendering, static site generation, API routes, fast refresh.
The React ecosystem is continuously evolving, with new tools and libraries emerging to address various needs and challenges in modern web development. These tools help streamline the development process, enhance performance, and ensure maintainability of React applications.
Pros and Cons of ReactJS
Today, ReactJS is the highly used open-source JavaScript Library. It helps in creating impressive web apps that require minimal effort and coding. The main objective of ReactJS is to develop User Interfaces (UI) that improves the speed of the apps. There are important pros and cons of ReactJS given as following:
Advantage of ReactJS
Easy to Learn and Use
ReactJS is much easier to learn and use. It comes with a good supply of documentation, tutorials, and training resources. Any developer who comes from a JavaScript background can easily understand and start creating web apps using React in a few days. It is the V(view part) in the MVC (Model-View-Controller) model, and referred to as ?one of the JavaScript frameworks.? It is not fully featured but has the advantage of open-source JavaScript User Interface(UI) library, which helps to execute the task in a better manner.
Creating Dynamic Web Applications Becomes Easier
JSX for Readability and Maintainability:
- JSX (JavaScript XML) allows developers to write HTML elements in JavaScript. This mixture of HTML and JavaScript makes the code more readable and maintainable. For example, instead of splitting code between HTML and JavaScript files, JSX enables developers to write them together, making it easier to understand and work with the code.
Reusable Components
A ReactJS web application is made up of multiple components, and each component has its own logic and controls. These components are responsible for outputting a small, reusable piece of HTML code which can be reused wherever you need them. The reusable code helps to make your apps easier to develop and maintain. These Components can be nested with other components to allow complex applications to be built of simple building blocks. ReactJS uses virtual DOM based mechanism to fill data in HTML DOM. The virtual DOM works fast as it only changes individual DOM elements instead of reloading complete DOM every time.
Performance Enhancement
Virtual DOM vs. Real DOM:
- React uses a virtual DOM to optimize updates and rendering. When the state of a component changes, React first updates the virtual DOM, a lightweight copy of the real DOM. It then compares this virtual DOM with a snapshot of the real DOM before applying only the necessary changes to the real DOM.Instead of re-rendering the entire DOM tree, React only updates the parts that have changed, which significantly boosts performance, especially in complex applications.
Known to be SEO Friendly
Traditional JavaScript frameworks have an issue in dealing with SEO. The search engines generally having trouble in reading JavaScript-heavy applications. Many web developers have often complained about this problem. ReactJS overcomes this problem that helps developers to be easily navigated on various search engines. It is because React.js applications can run on the server, and the virtual DOM will be rendering and returning to the browser as a regular web page.
The Benefit of Having JavaScript Library
Today, ReactJS is choosing by most of the web developers. It is because it is offering a very rich JavaScript library. The JavaScript library provides more flexibility to the web developers to choose the way they want.
Disadvantage of ReactJS
The high pace of development
Continuous Learning and Updates:
- The React ecosystem evolves rapidly, with frequent updates and new releases. While these updates bring improvements and new features, they also mean developers need to constantly learn and adapt. For example, React Hooks, introduced in version 16.8, brought a significant change in how state and side effects are handled.
Developers had to quickly learn and integrate this new feature, which can be challenging and time-consuming.
Poor Documentation
Rapid Updates Leading to Outdated Information:
- While the official React documentation has improved, the rapid pace of updates can sometimes lead to outdated or incomplete information. For example, when new features like Concurrent Mode or Suspense are introduced, documentation might lag behind, making it difficult for developers to find accurate and up-to-date information.
Developers might need to rely on community forums, blog posts, or other unofficial sources to fill in the gaps, which can be frustrating and time-consuming.
View Part
ReactJS Covers only the UI Layers of the app and nothing else. So you still need to choose some other technologies to get a complete tooling set for development in the project.
JSX as a barrier
ReactJS uses JSX. It's a syntax extension that allows HTML with JavaScript mixed together. This approach has its own benefits, but some members of the development community consider JSX as a barrier, especially for new developers. Developers complain about its complexity in the learning curve.