[TOC] # Service Workers PWA中的关键技术之一是 Service Workers。 服务工作者本质上是浏览器内部的可编程网络代理，它使您可以在浏览器需要发出网络请求并分派请求，或从缓存或本地存储中检索请求的信息时“捕获”。 这意味着Service Worker通过能够检测和响应应用程序中的离线或高延迟条件，使开发人员能够提供具有离线功能的体验。 有关服务人员的深入介绍，请查看Google的Matt Gaunt的这篇文章。 服务人员在Chrome和Firefox，Safari和Edge中提供支持，但在Internet Explorer中不提供支持。 有了Safari / iOS，Safari，Edge和Chrome以及适用于Android的Firefox都最近获得了支持。 # CSS-in-JS CSS-in-JS sounds just like what it is - instead of creating separate files for styling, the CSS is placed inside the JS files of the component. Writing CSS inside of your JS files may feel wrong and against your usual clean code standards, but some think this is beneficial as it helps keep everything you need for a component in one place. Actual CSS is generated when you use CSS-in-JS libraries and some even add support for non-native CSS features like nesting. Using this approach lets you stay in the context of your components, add isolation, scoped selectors, vendor prefixing, unit tests and more. Here are some of the most popular CSS-in-JS libraries: Styled Components, JSS-React, glamourous, Aphrodite and Styletron. > https://www.telerik.com/blogs/all-things-react#what-is-react # PropTypes # Pure Components # Preventing XSS vulnerabilities in React # 参考 [React 的历史](https://www.telerik.com/blogs/all-things-react#what-is-react)