What is react-primer-draft?

This repository is a written guide, or primer, for developers learning to build single-page web applications using React. React is a JavaScript library made by Facebook for building user interfaces in the browser. Rather than being a library you install, this repo is a document you read, with explanations and code examples organized by topic. The guide is structured as a series of parts. Part 1 covers the core React concepts: what a component is, how JSX works (the syntax that mixes HTML-like tags into JavaScript), how data flows through props, how a component manages its own internal state, and the lifecycle hooks that let you run code at specific moments like when a component first appears on the page or when it receives new data. Part 2 covers newer JavaScript syntax features from ES6 (also called ES2015 or Harmony), such as arrow functions, classes, and module imports. Later parts introduce tools and libraries that commonly appear in React projects: Webpack for bundling files, React Router for handling navigation between pages, Flux (via a library called Alt) for managing shared application state, and Mocha for testing. A bonus chapter covers using React inside a Ruby on Rails application. The author notes at the top that the guide was written for React 0.12.x, which is a very old version, and that it was a work in progress with Part 2 still incomplete at the time of writing. The core React concepts in Part 1 still apply to how React works, though some of the specific APIs and patterns described have changed in newer versions. This is a learning resource rather than an active project. It is best treated as a historical introduction that covers the mental model behind React, with the understanding that current documentation and courses will reflect the modern API more accurately. The full README is longer than what was shown.