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{{For|the open-source mobile application framework|React Native}}
{{Short description|JavaScript library for building user interfaces}}
{{Multiple issues|
{{More citations needed|date=May 2024}}
{{Self-published|date=May 2024}}
}}
{{Infobox software
| name
| logo = React Logo
| logo size = 130px
| author = Jordan Walke
| developer = [[Meta Platforms|Meta]] and community
| released = {{Start date and age|2013|5|29}}<ref name="Occhino-2013">{{cite web|access-date=22 Oct 2018|first1=Tom|first2=Jordan|last1=Occhino|last2=Walke|title=JS Apps at Facebook|url=https://www.youtube.com/watch?v=GW0rj4sNH2w|website=YouTube|date=5 August 2013 |archive-date=31 May 2022|archive-url=https://web.archive.org/web/20220531133559/https://www.youtube.com/watch?v=GW0rj4sNH2w|url-status=live}}</ref><ref>{{Cite web |date=2021-04-12 |title=Is React a Library or a Framework? Here's Why it Matters |url=https://www.freecodecamp.org/news/is-react-a-library-or-a-framework/ |access-date=2024-10-12 |website=freeCodeCamp.org |language=en}}</ref>
| ver layout = stacked
| latest release version = {{wikidata|property|reference|edit|P348}}
| latest release date
{{wikidata|qualifier|P348|P577}} }} | latest preview version = 19.0.0-rc.1
| latest preview date = {{Start date and age|2024|11|14}}<ref name="customelements">{{cite web|url=https://react.dev/blog/2024/04/25/react-19#whats-new-in-react-19|title=What's new in React 19|access-date=2024-05-12|archive-date=2024-05-12|archive-url=https://web.archive.org/web/20240512195006/https://react.dev/blog/2024/04/25/react-19#whats-new-in-react-19|url-status=live}}</ref>
| programming language
| platform
| genre
| license
| website = https://react.dev/
}}
'''React''' (also known as '''React.js''' or '''ReactJS''') is
React can be used to develop [[single-page application|single-page]], mobile, or [[server-side rendering|server-rendered]] applications with frameworks like [[Next.js]] and [[Remix (web framework)|Remix]]{{Efn|Merged into [[React Router]] since React Router v7<ref>{{Cite web |last=Lybrand |first=Brooks |date=2024-05-15 |title=Merging Remix and React Router |url=https://remix.run/blog/merging-remix-and-react-router |access-date=2024-12-25 |website=remix.run |language=en}}</ref>}}. Because React is only concerned with the user interface and rendering components to the [[Document Object Model|DOM]], React applications often rely on [[JavaScript libraries|libraries]] for routing and other client-side functionality.{{sfn|Dere|2017}}{{sfn|Panchal|2022}} A key advantage of React is that it only re-renders those parts of the page that have changed, avoiding unnecessary re-rendering of unchanged DOM elements.
== Notable features ==
=== Declarative ===
React adheres to the [[declarative programming]] [[Programming paradigm|paradigm]].<ref>{{Cite web |date=2017-09-27 |title=React Introduction |url=https://www.geeksforgeeks.org/reactjs-introduction/ |access-date=2024-10-12 |website=GeeksforGeeks |language=en-US}}</ref>{{sfn|Wieruch|2020}}{{rp|76}} Developers design views for each state of an application, and React updates and renders components when data changes. This is in contrast with [[imperative programming]].{{sfn|Schwarzmüller|2018}}
=== Components ===
React code is made of entities called [[Component-based software engineering|components]].{{sfn|Wieruch|2020}}{{rp|10-12}} These components are modular and can be reused.{{sfn|Wieruch|2020}}{{rp|70}} React applications typically consist of many layers of components. The components are rendered to a root element in the [[Document Object Model|DOM]] using the React DOM library. When rendering a component, values are passed between components through ''props'' (short for "properties")''.'' Values internal to a component are called its ''state.''<ref>{{cite web |title=Components and Props |url=https://reactjs.org/docs/components-and-props.html#props-are-read-only |url-status=live |access-date=7 April 2018 |website=React |publisher=Facebook |archive-date=7 April 2018 |archive-url=https://web.archive.org/web/20180407120115/https://reactjs.org/docs/components-and-props.html}}</ref>
The two primary ways of declaring components in React are through function components and class components.{{sfn|Wieruch|2020}}{{rp|118}}{{sfn|Larsen|2021}}{{rp|10}} Since React v16.8, using function components is the recommended way.
=== Function components ===
Function components, announced at React Conf 2018, and available since React v16.8, are declared with a function that accepts a single "props" argument and returns JSX. Function components can use internal state with the <code>useState</code> Hook.
<ref name="introducing_hooks"/>
=== React Hooks ===
On February 16, 2019, React 16.8 was released to the public, introducing React Hooks.<ref name="introducing_hooks">{{cite web
|url=https://reactjs.org/docs/hooks-intro.html
|title=Introducing Hooks
|publisher=react.js
|access-date=2019-05-20
|archive-date=2018-10-25
|archive-url=https://web.archive.org/web/20181025163202/https://reactjs.org/docs/hooks-intro.html
|url-status=live
}}</ref> Hooks are functions that let developers "hook into" React state and lifecycle features from function components.<ref>{{Cite web|url=https://reactjs.org/docs/hooks-overview.html|title=Hooks at a Glance – React|website=reactjs.org|language=en|access-date=2019-08-08|archive-date=2023-03-15|archive-url=https://web.archive.org/web/20230315054047/https://reactjs.org/docs/hooks-overview.html|url-status=live}}</ref> Notably, Hooks do not work inside classes — they let developers use more features of React without classes.<ref>{{Cite web |date=2020-01-16 |title=What the Heck is React Hooks? |url=https://soshace.com/2020/01/16/what-the-heck-is-react-hooks/ |url-status=live |archive-url=https://web.archive.org/web/20220531133601/https://blog.soshace.com/what-the-heck-is-react-hooks/ |archive-date=2022-05-31 |access-date=2020-01-24 |website=Soshace |language=en}}</ref>
React provides several built-in hooks such as <code>useState</code>,<ref>{{Cite web|url=https://reactjs.org/docs/hooks-state.html|title=Using the State Hook – React|website=reactjs.org|language=en|access-date=2020-01-24|archive-date=2022-07-30|archive-url=https://web.archive.org/web/20220730180312/https://reactjs.org/docs/hooks-state.html|url-status=live}}</ref>{{sfn|Larsen|2021}}{{rp|37}} <code>useContext</code>,{{sfn|Wieruch|2020}}{{rp|11}}<ref name="reactjs.org-2">{{Cite web|url=https://reactjs.org/docs/hooks-state.html|title=Using the State Hook – React|website=reactjs.org|language=en|access-date=2020-01-24|archive-date=2022-07-30|archive-url=https://web.archive.org/web/20220730180312/https://reactjs.org/docs/hooks-state.html|url-status=live}}</ref>{{sfn|Larsen|2021}}{{rp|12}} <code>useReducer</code>,{{sfn|Wieruch|2020}}{{rp|92}}<ref name="reactjs.org-2" />{{sfn|Larsen|2021}}{{rp|65-66}} <code>useMemo</code>{{sfn|Wieruch|2020}}{{rp|154}}<ref name="reactjs.org-2" />{{sfn|Larsen|2021}}{{rp|162}} and <code>useEffect</code>.<ref>{{Cite web|url=https://reactjs.org/docs/hooks-effect.html|title=Using the Effect Hook – React|website=reactjs.org|language=en|access-date=2020-01-24|archive-date=2022-08-01|archive-url=https://web.archive.org/web/20220801212858/https://reactjs.org/docs/hooks-effect.html|url-status=live}}</ref>{{sfn|Larsen|2021}}{{rp|93-95}} Others are documented in the Hooks API Reference.<ref>{{Cite web|url=https://reactjs.org/docs/hooks-reference.html|title=Hooks API Reference – React|website=reactjs.org|language=en|access-date=2020-01-24|archive-date=2022-08-05|archive-url=https://web.archive.org/web/20220805061010/https://reactjs.org/docs/hooks-reference.html|url-status=live}}</ref>{{sfn|Wieruch|2020}}{{rp|62}} <code>useState</code> and <code>useEffect</code>, which are the most commonly used, are for controlling [[State (computer science)|state]]{{sfn|Wieruch|2020}}{{rp|37}} and [[Side effect (computer science)|side effects]],{{sfn|Wieruch|2020}}{{rp|61}} respectively.
==== Rules of hooks ====
There are two rules of hooks<ref>{{Cite web|url=https://reactjs.org/docs/hooks-rules.html|title=Rules of Hooks – React|website=reactjs.org|language=en|access-date=2020-01-24|archive-date=2021-06-06|archive-url=https://web.archive.org/web/20210606174151/https://reactjs.org/docs/hooks-rules.html|url-status=live}}</ref> which describe the characteristic code patterns that hooks rely on:
# "Only call hooks at the top level" — do not call hooks from inside loops, conditions, or nested statements so that the hooks are called in the same order each render.
# "Only call hooks from React functions" — do not call hooks from plain JavaScript functions so that stateful logic stays with the component.
Although these rules cannot be enforced at runtime, code analysis tools such as [[Lint (software)|linters]] can be configured to detect many mistakes during development. The rules apply to both usage of Hooks and the implementation of custom Hooks,<ref>{{Cite web|url=https://reactjs.org/docs/hooks-custom.html|title=Building Your Own Hooks – React|website=reactjs.org|language=en|access-date=2020-01-24|archive-date=2022-07-17|archive-url=https://web.archive.org/web/20220717175155/https://reactjs.org/docs/hooks-custom.html|url-status=live}}</ref> which may call other Hooks.
=== Server components ===
React server components (RSC) <ref>{{Cite web|url=https://react.dev/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023#react-server-components|title=React Labs: What We've Been Working On – March 2023|website=react.dev|language=en|access-date=2023-07-23|archive-date=2023-07-26|archive-url=https://web.archive.org/web/20230726201006/https://react.dev/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023#react-server-components|url-status=live}}</ref> are function components that run exclusively on the server. The concept was first introduced in the talk "Data Fetching with Server Components".<ref>{{Cite web |last1=Abramov |first1=Dan |last2=Tan |first2=Lauren |last3=Savona |first3=Joseph |last4=Markbåge |first4=Sebastian |date=2020-12-21 |title=Introducing Zero-Bundle-Size React Server Components |url=https://react.dev/blog/2020/12/21/data-fetching-with-react-server-components |access-date=2024-09-28 |website=react.dev |language=en}}</ref> Though a similar concept to Server Side Rendering, RSCs do not send corresponding JavaScript to the client as no hydration occurs. As a result, they have no access to hooks. However, they may be [[Async/await|asynchronous function]], allowing them to directly perform asynchronous operations:
<syntaxhighlight lang="jsx" line="1">
async function MyComponent() {
const message = await fetchMessageFromDb();
return (
<div>Message: {message}</div>
);
}
</syntaxhighlight>
Currently, server components are most readily usable with [[Next.js]]. With Next.js, it's possible to write components for both the server and the client (browser). When a server rendered component is received by the browser, React in the browser takes over and creates the virtual DOM and attach event handlers. This is called hydration.
<ref>{{Cite web |title= hydrate |url=https://18.react.dev/reference/react-dom/hydrate#hydrating-server-rendered-html |access-date=2025-06-19 |language=en |archive-url=https://web.archive.org/web/20240716002720/https://18.react.dev/reference/react-dom/hydrate#hydrating-server-rendered-html |archive-date=2024-07-16 |url-status=live }}</ref>
=== Class components ===
Class components are declared using [[ECMAScript|ES6]] classes. They behave the same way that function components do, but instead of using Hooks to manage state and lifecycle events, they use the lifecycle methods on the <code>React.Component</code> [[Inheritance (object-oriented programming)|base class]].
<syntaxhighlight lang="jsx" line="1">
class ParentComponent extends React.Component {
state = { color: 'green' };
Line 71 ⟶ 92:
}
}
</syntaxhighlight>The introduction of React Hooks with React 16.8 in February 2019 allowed developers to manage state and lifecycle behaviors within functional components, reducing the reliance on class components.
This trend aligns with the broader industry movement towards functional programming and modular design. As React continues to evolve, it is essential for developers to consider the benefits of functional components and React Hooks when building new applications or refactoring existing ones.<ref>{{Cite web |last=Chourasia |first=Rawnak |date=2023-03-08 |title=Convert Class Component to Function(Arrow) Component – React |url=https://codeparttime.com/convert-class-to-function-arrow-react/ |access-date=2023-08-15 |website=Code Part Time |archive-date=2023-08-15 |archive-url=https://web.archive.org/web/20230815131020/https://codeparttime.com/convert-class-to-function-arrow-react/ |url-status=live }}</ref>
===
React itself does not come with built-in support for [[routing]]. React is primarily a library for building user interfaces, and it does not include a full-fledged routing solution out of the box. Third-party libraries can be used to handle routing in React applications.<ref>{{Cite web |date=2023-07-12 |title=Mastering React Router – The Ultimate Guide |url=https://www.devban.com/react-router-ultimate-guide/ |access-date=2023-07-26 |language=en-US |archive-date=2023-07-26 |archive-url=https://web.archive.org/web/20230726063450/https://www.devban.com/react-router-ultimate-guide/ |url-status=live }}</ref> It allows the developer to define routes, manage navigation, and handle URL changes in a React-friendly way.
[[File:VirtualDOM with respect to realDOM.png|thumb|There is a Virtual DOM that is used to implement the real DOM]]
===
Another notable feature is the use of a virtual [[Document Object Model]], or [[Virtual DOM]]. React creates an [[In-memory processing|in-memory]] data-structure, similar to the browser DOM. Every time components are rendered, the result is compared with the virtual DOM. It then updates the browser's displayed DOM efficiently with only the computed differences.<ref name="React Blog">{{cite web |title=Refs and the DOM |url=https://reactjs.org/docs/refs-and-the-dom.html |access-date=2021-07-19 |website=React Blog |archive-date=2022-08-07 |archive-url=https://web.archive.org/web/20220807171328/https://reactjs.org/docs/refs-and-the-dom.html |url-status=live }}</ref> This process is called '''reconciliation'''. This allows the programmer to write code as if the entire page is rendered on each change, while React only renders the components that actually change. This selective rendering provides a major performance boost.<ref name="Codecademy">{{Cite web |title=React: The Virtual DOM |url=https://www.codecademy.com/articles/react-virtual-dom |access-date=2021-10-14 |website=Codecademy |language=en |archive-date=2021-10-28 |archive-url=https://web.archive.org/web/20211028172953/https://www.codecademy.com/articles/react-virtual-dom |url-status=live }}</ref><ref name="Aggarwal">{{cite web |last1=Aggarwal |first1=Sanchit |title=Modern Web-Development using ReactJS |url=https://ijrra.net/Vol5issue1/IJRRA-05-01-27.pdf |website=International Journal of Recent Research Aspects |access-date=11 December 2024 |archive-url=https://web.archive.org/web/20240417143754/https://ijrra.net/Vol5issue1/IJRRA-05-01-27.pdf |archive-date=17 April 2024 |pages=133–137 |date=March 2018 |url-status=live}}</ref>
==== Updates ====
When <code>ReactDOM.render</code><ref>{{Cite web |title=ReactDOM – React |url=https://reactjs.org/docs/react-dom.html |access-date=2023-01-08 |website=reactjs.org |language=en |archive-date=2023-01-08 |archive-url=https://web.archive.org/web/20230108104936/https://reactjs.org/docs/react-dom.html |url-status=live }}</ref> is called again for the same component and target, React represents the new UI state in the Virtual DOM and determines which parts (if any) of the living DOM needs to change.<ref>{{Cite web |title=Reconciliation – React |url=https://reactjs.org/docs/reconciliation.html |access-date=2023-01-08 |website=reactjs.org |language=en |archive-date=2023-01-08 |archive-url=https://web.archive.org/web/20230108105122/https://reactjs.org/docs/reconciliation.html |url-status=live }}</ref>
[[File:React-example-virtual-dom-diff.svg|alt=Updates to realDOM are subject to virtualDOM|thumb|The virtualDOM will update the realDOM in real-time effortlessly]]
=== Lifecycle methods ===
Lifecycle methods for class-based components use a form of [[hooking]] that allows the execution of code at set points during a component's lifetime.
* <code>ShouldComponentUpdate</code> allows the developer to prevent unnecessary re-rendering of a component by returning false if a render is not required.
* <code>componentDidMount</code> is called once the component has "mounted" (the component has been created in the user interface, often by associating it with a [[Document Object Model|DOM]] node). This is commonly used to trigger data loading from a remote source via an [[API]].
* <code>componentDidUpdate</code> is invoked immediately after updating occurs.<ref>{{Cite web |title=React.Component – React |url=https://legacy.reactjs.org/docs/react-component.html |access-date=2024-04-09 |website=legacy.reactjs.org |language=en |archive-date=2024-04-09 |archive-url=https://web.archive.org/web/20240409075058/https://legacy.reactjs.org/docs/react-component.html |url-status=live }}</ref>
* <code>componentWillUnmount</code> is called immediately before the component is torn down or "unmounted". This is commonly used to clear resource-demanding dependencies to the component that will not simply be removed with the unmounting of the component (e.g., removing any <code>setInterval()</code> instances that are related to the component, or an "[[Event (computing)|eventListener]]" set on the "document" because of the presence of the component)
* <code>render</code> is the most important lifecycle method and the only required one in any component. It is usually called every time the component's state is updated, which should be reflected in the user interface.
=== JSX ===
{{Main|JSX (JavaScript)|l1=JSX}}
[[JSX (JavaScript)|JSX]], or JavaScript XML, is an extension to the JavaScript language syntax.<ref>{{cite web |date=2022-03-08 |title=Draft: JSX Specification |url=https://facebook.github.io/jsx/ |access-date=7 April 2018 |website=JSX |publisher=Facebook |language=en-US |archive-date=2022-04-02 |archive-url=https://web.archive.org/web/20220402072504/https://facebook.github.io/jsx/ |url-status=live }}</ref> Similar in appearance to HTML,{{sfn|Wieruch|2020}}{{rp|11}} JSX provides a way to structure component rendering using syntax familiar{{sfn|Wieruch|2020}}{{rp|15}} to many developers. React components are typically written using JSX, although they do not have to be (components may also be written in pure JavaScript). During compilation, JSX is converted to JavaScript code. JSX is similar to another extension syntax created by Facebook for [[PHP]] called [[XHP]].
<syntaxhighlight lang="
function Example() {
// Declare a new state variable, which we'll call "count"
const [count, setCount] = useState(0);
return (
<div>
<p>You clicked {count} times</p>
<button onClick={() => setCount(count + 1)}>
Click me
</button>
);
}
</syntaxhighlight>
=== Architecture beyond HTML ===
The basic [[Software architecture|architecture]] of React applies beyond rendering HTML in the browser. For example, Facebook has dynamic charts that render to <code><nowiki><canvas></nowiki></code> tags,<ref>{{cite web |last=Hunt |first=Pete |date=2013-06-05 |title=Why did we build React? – React Blog |url=https://facebook.github.io/react/blog/2013/06/05/why-react.html |access-date=2022-02-17 |website=reactjs.org |language=en-US |archive-date=2015-04-06 |archive-url=https://web.archive.org/web/20150406072833/http://facebook.github.io/react/blog/2013/06/05/why-react.html |url-status=dead }}</ref> and Netflix and [[PayPal]] use universal loading to render identical HTML on both the server and client.<ref name="medium.com-2015">{{cite web |date=2015-04-27 |title=PayPal Isomorphic React |url=https://medium.com/paypal-engineering/isomorphic-react-apps-with-react-engine-17dae662379c |url-status=live |archive-url=https://web.archive.org/web/20190208124143/https://www.paypal-engineering.com/2015/04/27/isomorphic-react-apps-with-react-engine/ |archive-date=2019-02-08 |access-date=2019-02-08 |website=medium.com}}</ref><ref name="netflixtechblog.com-2015">{{cite web |date=2015-01-28 |title=Netflix Isomorphic React |url=http://techblog.netflix.com/2015/01/netflix-likes-react.html |access-date=2022-02-14 |website=netflixtechblog.com |language=en-US |archive-date=2016-12-17 |archive-url=https://web.archive.org/web/20161217043150/http://techblog.netflix.com/2015/01/netflix-likes-react.html |url-status=live }}</ref> React can also be used to develop native apps for Android and iOS using [[React Native]].
=== Server-side rendering ===
[[Server-side scripting|Server-side rendering]] (SSR) refers to the process of rendering a client-side JavaScript application on the server, rather than in the browser.<ref name="MDNSSR">
{{cite web
|title=Server-side rendering (SSR) - MDN Web Docs Glossary
|url=https://developer.mozilla.org/en-US/docs/Glossary/SSR
|website=MDN Web Docs
|publisher=Mozilla
|access-date=7 March 2025
}}
</ref> This can improve the performance of the application, especially for users on slower connections or devices.<ref name="GoogleRendering">
{{cite web
|title=Rendering on the Web
|url=https://web.dev/rendering-on-the-web/
|website=web.dev
|publisher=Google
|date=6 February 2019
|access-date=7 March 2025
}}
</ref>
With SSR, the initial HTML that is sent to the client includes the fully rendered UI of the application.<ref name="CSS-Tricks-SSR">
{{cite web
|last=Jain
|first=Atishay
|title=Render Caching for React
|url=https://css-tricks.com/render-caching-for-react/
|website=CSS-Tricks
|date=10 November 2018
|access-date=7 March 2025
}}
</ref> This allows the client's browser to display the UI immediately, rather than having to wait for the JavaScript to download and execute before rendering the UI.<ref name="CSS-Tricks-SSR" />
React supports SSR, which allows developers to render React components on the server and send the resulting HTML to the client.<ref name="ReactDoc">
{{cite web
|title=Server React DOM APIs
|url=https://react.dev/reference/react-dom/server
|website=React Documentation
|publisher=Meta Platforms
|access-date=7 March 2025
}}
</ref> This can be useful for improving the performance of the application, as well as for [[search engine optimization]] purposes.<ref name="NextDocs">
{{cite web
|title=Rendering (Next.js Documentation)
|url=https://nextjs.org/docs/pages/building-your-application/rendering
|website=Next.js Documentation
|publisher=Vercel
|access-date=7 March 2025
}}
</ref>
== Common idioms ==
React does not attempt to provide a complete application library. It is designed specifically for building user interfaces<ref name="reactjs.org-3" /> and therefore does not include many of the tools some developers might consider necessary to build an application. This allows the choice of whichever libraries the developer prefers to accomplish tasks such as performing network access or local data storage. Common patterns of usage have emerged as the library matures.
=== Unidirectional data flow ===
{{Main|Unidirectional data flow}}
To support React's concept of unidirectional data flow (which might be contrasted with [[AngularJS]]'s bidirectional flow), the ''Flux'' architecture was developed as an alternative to the popular [[model–view–controller]] architecture. Flux features ''actions'' which are sent through a central ''dispatcher'' to a ''store'', and changes to the store are propagated back to the view.<ref name="Flux">{{cite web|url=https://facebook.github.io/flux/docs/in-depth-overview|title=In Depth OverView|publisher=Facebook|access-date=7 April 2018|website=Flux|archive-date=7 August 2022|archive-url=https://web.archive.org/web/20220807201252/https://facebook.github.io/flux/docs/in-depth-overview/|url-status=dead}}</ref> When used with React, this propagation is accomplished through component properties. Since its conception, Flux has been superseded by libraries such as [[Redux (JavaScript library)|Redux]] and MobX.<ref>{{cite web|title=Flux Release 4.0|url=https://github.com/facebook/flux/releases/tag/4.0.0|website=Github|access-date=26 February 2021|archive-date=31 May 2022|archive-url=https://web.archive.org/web/20220531133558/https://github.com/facebook/flux/releases/tag/4.0.0|url-status=live}}</ref>
Flux can be considered a variant of the [[observer pattern]].<ref>{{cite web|last1=Johnson|first1=Nicholas|title=Introduction to Flux – React Exercise|url=http://nicholasjohnson.com/react/course/exercises/flux/|website=Nicholas Johnson|access-date=7 April 2018|archive-date=31 May 2022|archive-url=https://web.archive.org/web/20220531133600/http://nicholasjohnson.com/react/course/exercises/flux/|url-status=live}}</ref>
A React component under the Flux architecture should not directly modify any props passed to it, but should be passed [[callback function]]s that create ''actions'' which are sent by the dispatcher to modify the store. The action is an object whose responsibility is to describe what has taken place: for example, an action describing one user "following" another might contain a user id, a target user id, and the type <code>USER_FOLLOWED_ANOTHER_USER</code>.<ref>{{cite web|last1=Abramov|first1=Dan|title=The History of React and Flux with Dan Abramov|url=http://threedevsandamaybe.com/the-history-of-react-and-flux-with-dan-abramov/|website=Three Devs and a Maybe|access-date=7 April 2018|archive-date=19 April 2018|archive-url=https://web.archive.org/web/20180419075905/http://threedevsandamaybe.com/the-history-of-react-and-flux-with-dan-abramov/|url-status=live}}</ref> The stores, which can be thought of as models, can alter themselves in response to actions received from the dispatcher.
This pattern is sometimes expressed as "properties flow down, actions flow up". Many implementations of Flux have been created since its inception, perhaps the most well-known being [[Redux (JavaScript library)|Redux]], which features a single store, often called a [[single source of truth]].<ref>{{cite web|title=State Management Tools – Results|url=http://2016.stateofjs.com/2016/statemanagement/|website=The State of JavaScript|access-date=29 October 2021|archive-date=31 May 2022|archive-url=https://web.archive.org/web/20220531133609/http://2016.stateofjs.com/2016/statemanagement/|url-status=live}}</ref>
In February 2019, <code>useReducer</code> was introduced as a [[#React Hooks|React hook]] in the 16.8 release. It provides an API that is consistent with Redux, enabling developers to create Redux-like stores that are local to component states.<ref>{{Cite web |url=https://reactjs.org/blog/2019/02/06/react-v16.8.0.html#react-1 |title=React v16.8: The One with Hooks |access-date=2023-01-08 |archive-date=2023-01-08 |archive-url=https://web.archive.org/web/20230108090021/https://reactjs.org/blog/2019/02/06/react-v16.8.0.html#react-1 |url-status=live }}</ref>
==
React was created by Jordan Walke, a software engineer at [[Meta Platforms|Meta]], who initially developed a prototype called "F-Bolt"<ref name="Youtube-2023">{{cite web |title=React.js: The Documentary |url=https://youtube.com/watch?v=8pDqJVdNa44%3Fsi%3DFMJqegC4dPtwKP__&t=528 |website=Youtube | date=10 February 2023 |publisher=Honeypot |access-date=2024-05-27 |archive-date=2024-01-19 |archive-url=https://web.archive.org/web/20240119211307/https://www.youtube.com/watch?v=8pDqJVdNa44%3Fsi%3DFMJqegC4dPtwKP__&t=528 |url-status=live }}</ref> before later renaming it to "FaxJS". This early version is documented in Jordan Walke's GitHub repository.{{ref|Walke, Jordan. "FaxJS." GitHub. https://github.com/jordwalke/FaxJs. Accessed 11 July 2019.}} Influences for the project included [[XHP]], an [[HTML]] component library for [[PHP]].
React was first deployed on Facebook's [[News Feed]] in 2011 and subsequently integrated into [[Instagram]] in 2012.<ref name="Lopez">{{cite web |last1=Lopez |first1=Marny |title=Why React is so widely adopted by web developers? |url=https://www.devlane.com/blog/why-react-is-so-widely-adopted-by-web-developers |website=Devlane |access-date=11 December 2024 |archive-url=https://web.archive.org/web/20240620092857/https://www.devlane.com/blog/why-react-is-so-widely-adopted-by-web-developers |archive-date=20 June 2024 |date=13 May 2024 |url-status=live}}</ref> In May 2013, at JSConf US, the project was officially open-sourced, marking a significant turning point in its adoption and growth.{{ref|Hámori, Emergent. "React – The Pragmatic Guide." 2022.}}
[[React Native]], which enables native [[Android (operating system)|Android]], [[iOS]], and [[Universal Windows Platform|UWP]] development with React, was announced at Facebook's React Conf in February 2015 and open-sourced in March 2015.
On April 18, 2017, Facebook announced React Fiber, a new set of internal algorithms for rendering, as opposed to React's old rendering algorithm, Stack.{{sfn|Lardinois|2017}} React Fiber was to become the foundation of any future improvements and feature development of the React library.<ref>{{cite web|title = React Fiber Architecture|url = https://github.com/acdlite/react-fiber-architecture|website = Github|access-date = 19 April 2017|archive-date = 10 May 2018|archive-url = https://web.archive.org/web/20180510140634/https://github.com/acdlite/react-fiber-architecture|url-status = live}}</ref>{{Update inline|reason=Last commit was in 2016. Is this statement still true?|date=June 2018}} The actual syntax for programming with React does not change; only the way that the syntax is executed has changed.<ref name="TechCrunch-2017">{{cite web|url=https://techcrunch.com/2017/04/18/facebook-announces-react-fiber-a-rewrite-of-its-react-framework/|title=Facebook announces React Fiber, a rewrite of its React framework|website=TechCrunch|date=18 April 2017 |accessdate=2018-10-19|archive-date=2018-06-14|archive-url=https://web.archive.org/web/20180614172053/https://techcrunch.com/2017/04/18/facebook-announces-react-fiber-a-rewrite-of-its-react-framework/|url-status=live}}</ref> React's old rendering system, Stack, was developed at a time when the focus of the system on dynamic change was not understood. Stack was slow to draw complex animation, for example, trying to accomplish all of it in one chunk. Fiber breaks down animation into segments that can be spread out over multiple frames. Likewise, the structure of a page can be broken into segments that may be maintained and updated separately. JavaScript functions and virtual [[Document Object Model|DOM]] objects are called "fibers", and each can be operated and updated separately, allowing for smoother on-screen rendering.<ref name="github.com">{{cite web|url=https://github.com/acdlite/react-fiber-architecture|title=GitHub – acdlite/react-fiber-architecture: A description of React's new core algorithm, React Fiber|website=github.com|accessdate=2018-10-19|archive-date=2018-05-10|archive-url=https://web.archive.org/web/20180510140634/https://github.com/acdlite/react-fiber-architecture|url-status=live}}</ref>
On September 26, 2017, React 16.0 was released to the public.<ref>{{cite web
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|date=2017-09-26
|access-date=2019-05-20
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|archive-url=https://web.archive.org/web/20171003031315/https://reactjs.org/blog/2017/09/26/react-v16.0.html
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On October 20, 2020, the React team released React v17.0, notable as the first major release without major changes to the React developer-facing API.<ref>url=https://reactjs.org/blog/2020/08/10/react-v17-rc.html {{Webarchive|url=https://web.archive.org/web/20200810215037/https://reactjs.org/blog/2020/08/10/react-v17-rc.html |date=2020-08-10 }}</ref>
On
On December 5, 2024, React 19 was released. This release introduced Actions, which simplify the process of making state updates using asynchronous functions rather than having to manually handle pending states, errors and optimistic updates. React 19 also included support for server components and improved static site generation.<ref>{{cite web |title=React 19 |url=https://react.dev/blog/2024/12/05/react-19#whats-new-in-react-19 |website=React |access-date=7 December 2024}}</ref>
{| class="wikitable mw-collapsible mw-collapsed"
|+ class="nowrap" | Version history of react
|-
!Version
! width="150px" | Release Date
!Changes
|-
Line 241 ⟶ 245:
|0.4.0
|20 July 2013
|Support for comment nodes
|-
|0.5.0
Line 249 ⟶ 253:
|0.8.0
|20 December 2013
|Added support for rows & cols, defer & async, loop for
|-
|0.9.0
|20 February 2014
|Added support for crossOrigin, download and hrefLang, mediaGroup and muted, sandbox, seamless, and srcDoc, scope attributes, Added any, arrayOf, component, oneOfType, renderable, shape to React.PropTypes, Added support for onMouseOver and onMouseOut event, Added support for onLoad and onError on
|-
|0.10.0
|21 March 2014
|Added support for srcSet and textAnchor attributes, add update function for immutable data, Ensure all void elements
|-
|0.11.0
Line 270 ⟶ 274:
|10 March 2015
|Deprecated patterns that warned in 0.12 no longer work, ref resolution order has changed, Removed properties this._pendingState and this._rootNodeID, Support ES6 classes, Added API React.findDOMNode(component), Support for iterators and immutable-js sequences, Added new features React.addons.createFragment, deprecated React.addons.classSet.
|-
|15.0.0
|7 April 2016
|Initial render now uses document.createElement instead of generating HTML, No more extra
|-
|15.1.0
Line 285:
|15.2.0
|1 July 2016
|Include component stack information, Stop validating props at mount time, Add React.PropTypes.symbol, Add onLoad handling to
|-
|15.3.0
|30 July 2016
|Add React.PureComponent, Fix issue with nested server rendering, Add xmlns, xmlnsXlink to support SVG attributes and referrerPolicy to HTML attributes, updates React Perf Add-on, Fixed issue with ref.
|-
|15.4.0
|16 November 2016
|React package and browser build no longer includes React DOM, Improved development performance, Fixed occasional test failures, update batchedUpdates API, React Perf, and {{code|ReactTestRenderer.create()}}.
|-
|15.5.0
|7 April 2017
|Added react-dom/test-utils, Removed peerDependencies, Fixed issue with Closure Compiler, Added a deprecation warning for React.createClass and React.PropTypes, Fixed Chrome bug.
|-
|15.6.0
Line 330 ⟶ 314:
|29 March 2018
|Add a new officially supported context API, Add new packagePrevent an infinite loop when attempting to render portals with SSR, Fix an issue with this.state, Fix an IE/Edge issue.
|-
|16.4.0
|24 May 2018
|Add support for Pointer Events specification, Add the ability to specify propTypes, Fix reading context, Fix the {{code|getDerivedStateFromProps()}} support, Fix a testInstance.parent crash, Add React.unstable_Profiler component for measuring performance, Change internal event names.
|-
|16.5.0
Line 349 ⟶ 325:
|16.6.0
|23 October 2018
|Add support for contextType, Support priority levels, continuations, and wrapped callbacks, Improve the fallback mechanism, Fix gray overlay on iOS Safari, Add {{code|React.lazy()}} for code splitting components.
|-
|16.7.0
Line 357 ⟶ 333:
|16.8.0
|6 February 2019
|Add Hooks, Add {{code|ReactTestRenderer.act()}} and {{code|ReactTestUtils.act()}} for batching updates, Support synchronous thenables passed to React.lazy(), Improve useReducer Hook lazy initialization API.
|-
|16.9.0
|9 August 2019
|Add
|-
|16.10.0
|27 September 2019
|Fix edge case where a hook update
|-
|16.11.0
|22 October 2019
|Fix mouseenter handlers from firing twice inside nested React containers. Remove unstable_createRoot and unstable_createSyncRoot experimental APIs. (These are available in the Experimental channel as createRoot and createSyncRoot.)
|-
|16.12.0
|14 November 2019
|React DOM
|-
|16.13.0
|26 February 2020
|Features added in React Concurrent mode. Fix regressions in React core library and React Dom.
|-
|16.14.0
Line 405 ⟶ 361:
|17.0.0
|20 October 2020
|"No New Features" enables gradual React updates from older versions. Add new JSX Transform, Changes to Event Delegation
|-
|
|29 March 2022
|Concurrent React, Automatic batching, New Suspense Features, Transitions, Client and Server Rendering APIs, New Strict Mode Behaviors, New Hooks <ref name="reactjs.org">{{cite web|title=React v18.0|url=https://reactjs.org/blog/2022/03/29/react-v18.html|website=reactjs.org|language=en|access-date=2022-04-12|archive-date=2022-03-29|archive-url=https://web.archive.org/web/20220329160934/https://reactjs.org/blog/2022/03/29/react-v18.html|url-status=live}}</ref>
|-
|18.1.0
|26 April 2022
|Many fixes and performance improvements
|-
|18.2.0
|14 June 2022
|Many more fixes and performance improvements
|-
|18.3.0
|25 April 2024
|Adds deprecation warnings for features in React 19.
|-
|19.0.0
|5 December 2024
|Actions, new hooks (useActionState, useFormStatus, useOptimistic), use API, Server Components, Server Actions, passing ref as a normal prop, improved hydration diffs, improved Context API, cleanup functions for refs, improved useDeferredValue API, support for document metadata, support for stylesheets, support for async scripts, support for preloading resources, improved error reporting, and support for custom elements.
|}
== Licensing ==
The initial public release of React in May 2013 used the [[Apache License 2.0]]. In October 2014, React 0.12.
Based on community feedback, Facebook updated the patent grant in April 2015 to be less ambiguous and more permissive:<ref>{{cite web|title=Updating Our Open Source Patent Grant|url=https://code.facebook.com/posts/1639473982937255/updating-our-open-source-patent-grant/|access-date=2015-12-09|archive-date=2020-11-08|archive-url=https://web.archive.org/web/20201108114832/https://code.facebook.com/posts/1639473982937255/updating-our-open-source-patent-grant/|url-status=live}}</ref>
<blockquote>The license granted hereunder will terminate, automatically and without notice, if you (or any of your subsidiaries, corporate affiliates or agents) initiate directly or indirectly, or take a direct financial interest in, any Patent Assertion: (i) against Facebook or any of its subsidiaries or corporate affiliates, (ii) against any party if such Patent Assertion arises in whole or in part from any software, technology, product or service of Facebook or any of its subsidiaries or corporate affiliates, or (iii) against any party relating to the Software. [...] A "Patent Assertion" is any lawsuit or other action alleging direct, indirect, or contributory infringement or inducement to infringe any patent, including a cross-claim or counterclaim.<ref>{{cite web|title=Additional Grant of Patent Rights Version 2|url=https://github.com/facebook/react/blob/b8ba8c83f318b84e42933f6928f231dc0918f864/PATENTS|website=GitHub|access-date=2015-12-09|archive-date=2022-05-31|archive-url=https://web.archive.org/web/20220531133320/https://github.com/facebook/react/blob/b8ba8c83f318b84e42933f6928f231dc0918f864/PATENTS|url-status=live}}</ref></blockquote>
The [[Apache Software Foundation]] considered this licensing arrangement to be incompatible with its licensing policies, as it "passes along risk to downstream consumers of our software imbalanced in favor of the licensor, not the licensee, thereby violating our Apache legal policy of being a universal donor", and "are not a subset of those found in the [Apache License 2.0], and they cannot be sublicensed as [Apache License 2.0]".<ref>{{Cite web|url=https://www.apache.org/legal/resolved.html|title=ASF Legal Previously Asked Questions|publisher=Apache Software Foundation|language=en|access-date=2017-07-16|archive-date=2018-02-06|archive-url=https://web.archive.org/web/20180206232339/http://www.apache.org/legal/resolved.html|url-status=live}}</ref> In August 2017, Facebook dismissed the Apache Foundation's downstream concerns and refused to reconsider their license.<ref>{{Cite web|url=https://code.facebook.com/posts/112130496157735/explaining-react-s-license/|title=Explaining React's License|website=Facebook|access-date=2017-08-18|language=en|archive-date=2021-05-06|archive-url=https://web.archive.org/web/20210506164245/https://code.facebook.com/posts/112130496157735/explaining-react-s-license|url-status=live}}</ref><ref>{{Cite web|url=https://github.com/facebook/react/issues/10191#issuecomment-323486580|title=Consider re-licensing to AL v2.0, as RocksDB has just done|website=Github|language=en|access-date=2017-08-18|archive-date=2022-07-27|archive-url=https://web.archive.org/web/20220727100939/https://github.com/facebook/react/issues/10191#issuecomment-323486580|url-status=live}}</ref> The following month, [[WordPress]] decided to switch its Gutenberg and Calypso projects away from React.<ref>{{Cite web|url=
On September 23, 2017, Facebook announced that the following week, it would re-license Flow,
On September 26, 2017, React 16.0.0 was released with the MIT license.<ref>{{cite web |url=https://reactjs.org/blog/2017/09/26/react-v16.0.html#mit-licensed |title=
== Comparison with other frameworks ==
JavaScript-based web application frameworks, such as React, provide extensive capabilities but come with associated trade-offs. These frameworks often extend or enhance features available through native web technologies, such as routing, component-based development, and state management. While native web standards, including Web Components, modern JavaScript APIs like Fetch and ES Modules, and browser capabilities like Shadow DOM, have advanced significantly, frameworks remain widely used for their ability to enhance developer productivity, offer structured patterns for large-scale applications, simplify handling edge cases, and provide tools for performance optimization. <ref name=":02">{{Cite book |title=JavaScript Frameworks for Modern Web Development: The Essential Frameworks, Libraries, and Tools to Learn Right Now |isbn=978-1484249949 |last1=Uzayr |first1=Sufyan bin |last2=Cloud |first2=Nicholas |last3=Ambler |first3=Tim |date=November 2019 |publisher=Apress }}</ref><ref name=":12">{{Cite book |title=Building Native Web Components: Front-End Development with Polymer and Vue.js |isbn=978-1484259047}}</ref><ref name=":22">{{Cite book |title=Hands-On JavaScript High Performance: Build faster web apps using Node.js, Svelte.js, and WebAssembly |isbn=978-1838821098}}</ref>
Frameworks can introduce abstraction layers that may contribute to performance overhead, larger bundle sizes, and increased complexity. Modern frameworks, such as React 18, address these challenges with features like concurrent rendering, tree-shaking, and selective hydration. While these advancements improve rendering efficiency and resource management, their benefits depend on the specific application and implementation context. Lightweight frameworks, such as Svelte and Preact, take different architectural approaches, with Svelte eliminating the virtual DOM entirely in favor of compiling components to efficient JavaScript code, and Preact offering a minimal, compatible alternative to React. Framework choice depends on an application’s requirements, including the team’s expertise, performance goals, and development priorities. <ref name=":02" /><ref name=":12" /><ref name=":22" />
A newer category of web frameworks, including enhance.dev, Astro, and Fresh, leverages native web standards while minimizing abstractions and development tooling. <ref>{{Cite web |title=Enhance |website=[[GitHub]] |url=https://github.com/enhance-dev }}</ref><ref>{{Cite web |title=Astro framework |website=[[GitHub]] |url=https://github.com/withastro/astro }}</ref><ref>{{Cite web |title=Fresh |website=[[GitHub]] |url=https://github.com/denoland/fresh }}</ref> These solutions emphasize [[progressive enhancement]], [[server-side rendering]], and optimizing performance. Astro renders static HTML by default while hydrating only interactive parts. Fresh focuses on server-side rendering with zero runtime overhead. Enhance.dev prioritizes progressive enhancement patterns using Web Components. While these tools reduce reliance on client-side JavaScript by shifting logic to build-time or server-side execution, they still use JavaScript where necessary for interactivity. This approach makes them particularly suitable for performance-critical and content-focused applications. <ref name=":02" /><ref name=":12" /><ref name=":22" />
== See also ==
{{Portal|Free and open-source software}}
* [[
* [[
* [[Ember.js]]
* [[Gatsby (JavaScript framework)]]
* [[
* [[
* [[
* [[Vue.js]]
* [[Comparison of JavaScript-based web frameworks]]
* [[Web Components]]
==
{{Notelist}}
== References ==
{{Reflist|2}}
== Bibliography ==
{{Refbegin}}
* {{cite book |last=Larsen |first=John |title=React Hooks in Action With Suspense and Concurrent Mode |year=2021 |publisher=Manning |isbn=978-1-72004-399-7}}
* {{cite book |last1=Schwarzmüller |first1=Max |date=2018-05-01 |title=React – The Complete Guide (incl. Hooks, React Router and Redux) |publisher=[[Packt Publishing]] |language=en-US}}
* {{cite book |last=Wieruch |first=Robin |title=The Road to React |publisher=Leanpub |isbn=978-1-72004-399-7 |year=2020}}
* {{cite news |last=Dere |first=Mohan |date=2017-12-21 |title=How to integrate create-react-app with all the libraries you need to make a great app |language=en-US |work=freeCodeCamp |url=https://www.freecodecamp.org/news/how-to-make-create-react-app-work-with-a-node-backend-api-7c5c48acb1b0 |access-date=2018-06-14 }}
* {{cite news |last=Panchal |first=Krunal |date=2022-04-26 |title=Angular vs React Detailed Comparison |language=en-US |work=SitePoint |url=https://www.sitepoint.com/angular-vs-react/ |access-date=2023-06-05 |archive-date=2023-03-30 |archive-url=https://web.archive.org/web/20230330160838/https://www.sitepoint.com/angular-vs-react/ |url-status=live }}
* {{cite news |last1=Hámori |first1=Fenerec |title=The History of React.js on a Timeline |url=https://blog.risingstack.com/the-history-of-react-js-on-a-timeline/ |access-date=2023-06-05 |work=RisingStack |date=2022-05-31 |archive-date=2022-05-31 |archive-url=https://web.archive.org/web/20220531133616/https://blog.risingstack.com/the-history-of-react-js-on-a-timeline/ |url-status=live }}
* {{cite news |last=Lardinois |first=Frederic |title=Facebook announces React Fiber, a rewrite of its React framework |date=2017-04-18 |url=https://techcrunch.com/2017/04/18/facebook-announces-react-fiber-a-rewrite-of-its-react-framework/ |access-date=2024-12-31 |website=[[TechCrunch]] }}
{{Refend}}
== External links ==
* {{Official website}}
* [https://github.com/facebook/react Github]
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