Understanding React - Part 0. IntroductionMay 25# Tech# Front-End# React
Introduction to React
React is one of the most popular libraries for building fast and efficient front-end applications. It has revolutionized the way we develop web pages, enhancing both our development mindset and productivity.
The Development Experience Before React
Before React, developers followed a process-driven approach, using libraries like jQuery to build web applications. This approach required explicit, step-by-step instructions to achieve a specific outcome, often resulting in complex, imperative code that was hard to maintain and scale. Each UI change demanded direct DOM manipulation, which could lead to performance issues and bugs.
The Development Experience with React
In contrast, React introduces a behavior-driven development paradigm. By defining the desired UI state and letting React handle the rendering, developers can focus on the application's behavior rather than its implementation details. This declarative approach, enabled by React's component-based architecture, promotes reusability, better code organization, and improved performance. With React, developers can describe what they want to achieve, and the framework takes care of the rest.
Exploring Key Questions
If you have used React, you are likely familiar with terms like function components, hooks, and fiber. If not, I recommend creating a simple React demo to get a feel for it.
Now, consider this: what does React actually do, and how is the UI updated when setState is called? You might think, "Oh, the re-render is performed!" But what exactly is a re-render? How does React manage re-rendering for thousands of elements in your application?
Additionally, you may have encountered some peculiar issues during development. For example, why doesn't calling setState twice in a row result in two state updates? Why does updating the state in a parent component trigger a re-render of its child components?
To uncover the magic behind React and become a more proficient React developer, I delved into the source code and decided to write a series of posts to explain the underlying mechanisms.
Roadmap of the Series
To address these questions and gain a deeper understanding of React, I rewrote React using TypeScript, implementing its core functions to ensure it behaves like the official React. This series of posts aims to document my insights and assist other developers in exploring React's inner workings. The series includes:
- Understanding React Elements and JSX
- Exploring React Fiber
- The React Reconciler: How It Works
- The Diff Algorithm in React
- Implementing Function Components and Hooks
- Building React DOM
Conclusion and What's Next
By learning about React's mechanisms and rebuilding it line by line, you will gain a profound understanding of how React operates. This knowledge will empower you to write more efficient, scalable, and maintainable code.
Stay tuned for the upcoming posts in this series, where we will dive deep into each of these topics, unraveling the intricacies of React and enhancing our development skills together.
