Go to file
Brian Vaughn 51947a14bb
Refactored how React/DevTools log Timeline performance data (#23102)
Until now, DEV and PROFILING builds of React recorded Timeline profiling data using the User Timing API. This commit changes things so that React records this data by calling methods on the DevTools hook. (For now, DevTools still records that data using the User Timing API, to match previous behavior.)

This commit is large but most of it is just moving things around:

* New methods have been added to the DevTools hook (in "backend/profilingHooks") for recording the Timeline performance events.
* Reconciler's "ReactFiberDevToolsHook" has been updated to call these new methods (when they're present).
* User Timing method calls in "SchedulingProfiler" have been moved to DevTools "backend/profilingHooks" (to match previous behavior, for now).
* The old reconciler tests, "SchedulingProfiler-test" and "SchedulingProfilerLabels-test", have been moved into DevTools "TimelineProfiler-test" to ensure behavior didn't change unexpectedly.
* Two new methods have been added to the injected renderer interface: injectProfilingHooks() and getLaneLabelMap().

Relates to #22529.
2022-01-13 14:55:54 -05:00
.circleci Run DevTools e2e tests on Circle CI (#23019) 2022-01-04 10:28:03 -05:00
.codesandbox Update Node.js to latest v14.17.6 LTS (#22401) 2021-09-24 00:30:12 +01:00
.github Update PULL_REQUEST_TEMPLATE.md 2021-09-07 07:54:34 +01:00
fixtures Remove hydrate option from createRoot (#22878) 2021-12-07 16:10:00 -05:00
packages Refactored how React/DevTools log Timeline performance data (#23102) 2022-01-13 14:55:54 -05:00
scripts Refactored how React/DevTools log Timeline performance data (#23102) 2022-01-13 14:55:54 -05:00
.editorconfig https link to editorconfig.org (#18421) 2020-03-29 15:18:52 +01:00
.eslintignore Renamed packages/react-devtools-scheduling-profiler to packages/react-devtools-timeline (#22691) 2021-11-04 10:02:06 -04:00
.eslintrc.js Update deprecated features in ESLint configuration files. (#22767) 2021-11-23 22:53:26 +00:00
.gitattributes .gitattributes to ensure LF line endings when we should 2014-01-17 16:25:53 -08:00
.gitignore Renamed packages/react-devtools-scheduling-profiler to packages/react-devtools-timeline (#22691) 2021-11-04 10:02:06 -04:00
.mailmap updates mailmap entries (#19824) 2020-09-12 13:05:52 -04:00
.nvmrc Update Node.js to latest v14.17.6 LTS (#22401) 2021-09-24 00:30:12 +01:00
.prettierignore Renamed packages/react-devtools-scheduling-profiler to packages/react-devtools-timeline (#22691) 2021-11-04 10:02:06 -04:00
.prettierrc.js Bump Prettier (#17811) 2020-01-09 13:54:11 +00:00
.watchmanconfig .watchmanconfig must be valid json (#16118) 2019-07-11 19:01:02 -07:00
AUTHORS Remove my deadname from AUTHORS (#21152) 2021-03-31 23:13:13 +01:00
CHANGELOG.md Updated scripts and config to replace "master" with "main" branch (#21768) 2021-06-29 14:26:24 -04:00
CODE_OF_CONDUCT.md Update code of conduct (#21251) 2021-04-13 19:33:31 -04:00
CONTRIBUTING.md [Gatsby] "https://facebook.github.io/react/" -> "https://reactjs.org/" (#10970) 2017-09-29 18:43:22 -07:00
LICENSE Drop the year from Facebook copyright headers and the LICENSE file. (#13593) 2018-09-07 15:11:23 -07:00
README.md Fixed Link on Documentation (#22465) 2021-09-30 09:58:01 -04:00
ReactVersions.js Use `next` as prerelease label 2021-12-08 10:57:25 -05:00
SECURITY.md Create SECURITY.md (#15784) 2020-01-09 14:07:41 -08:00
appveyor.yml Updated scripts and config to replace "master" with "main" branch (#21768) 2021-06-29 14:26:24 -04:00
babel.config.js Babel 7 (#16297) 2019-08-08 17:46:35 -07:00
dangerfile.js Improve DEV errors if string coercion throws (Temporal.*, Symbol, etc.) (#22064) 2021-09-27 10:05:07 -07:00
netlify.toml add netlify toml file (#12350) 2018-05-20 21:03:51 +01:00
package.json Add CI job to check npm dependencies (#22881) 2021-12-07 23:09:00 -08:00
yarn.lock Ensure react-is version used for resolution for playwright is installed (#22813) 2021-11-23 13:29:47 -05:00

README.md

React · GitHub license npm version CircleCI Status PRs Welcome

React is a JavaScript library for building user interfaces.

  • Declarative: React makes it painless to create interactive UIs. Design simple views for each state in your application, and React will efficiently update and render just the right components when your data changes. Declarative views make your code more predictable, simpler to understand, and easier to debug.
  • Component-Based: Build encapsulated components that manage their own state, then compose them to make complex UIs. Since component logic is written in JavaScript instead of templates, you can easily pass rich data through your app and keep state out of the DOM.
  • Learn Once, Write Anywhere: We don't make assumptions about the rest of your technology stack, so you can develop new features in React without rewriting existing code. React can also render on the server using Node and power mobile apps using React Native.

Learn how to use React in your own project.

Installation

React has been designed for gradual adoption from the start, and you can use as little or as much React as you need:

You can use React as a <script> tag from a CDN, or as a react package on npm.

Documentation

You can find the React documentation on the website.

Check out the Getting Started page for a quick overview.

The documentation is divided into several sections:

You can improve it by sending pull requests to this repository.

Examples

We have several examples on the website. Here is the first one to get you started:

function HelloMessage({ name }) {
  return <div>Hello {name}</div>;
}

ReactDOM.render(
  <HelloMessage name="Taylor" />,
  document.getElementById('container')
);

This example will render "Hello Taylor" into a container on the page.

You'll notice that we used an HTML-like syntax; we call it JSX. JSX is not required to use React, but it makes code more readable, and writing it feels like writing HTML. If you're using React as a <script> tag, read this section on integrating JSX; otherwise, the recommended JavaScript toolchains handle it automatically.

Contributing

The main purpose of this repository is to continue evolving React core, making it faster and easier to use. Development of React happens in the open on GitHub, and we are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving React.

Code of Conduct

Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.

Contributing Guide

Read our contributing guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React.

Good First Issues

To help you get your feet wet and get you familiar with our contribution process, we have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started.

License

React is MIT licensed.