Content deleted Content added
m add website |
Thunder491 (talk | contribs) mNo edit summary |
||
| (23 intermediate revisions by 13 users not shown) | |||
Line 9:
| name = React
| logo = React Logo SVG.svg
| logo size =
| author = Jordan Walke
| developer = [[Meta Platforms|Meta]] and community
Line 29:
'''React''' (also known as '''React.js''' or '''ReactJS''') is a [[free and open-source software|free and open-source]] [[frontend and backend|front-end]] [[JavaScript library]]<ref name="reactjs.org-3">{{Cite web |title=React – A JavaScript library for building user interfaces. |url=https://reactjs.org |url-status=live |access-date=7 April 2018 |website=reactjs.org |language=en-US |archive-date=April 8, 2018 |archive-url=https://web.archive.org/web/20180408084010/https://reactjs.org/ }}</ref><ref>{{Cite web |title=Chapter 1. What Is React? - What React Is and Why It Matters [Book] |url=https://www.oreilly.com/library/view/what-react-is/9781491996744/ch01.html |url-status=live |access-date=2023-05-06 |website=www.oreilly.com |language=en |archive-date=May 6, 2023 |archive-url=https://web.archive.org/web/20230506100446/https://www.oreilly.com/library/view/what-react-is/9781491996744/ch01.html }}</ref> that aims to make building [[user interface]]s based on [[component-based software engineering|components]] more "seamless".<ref name="reactjs.org-3" /> It is maintained by [[Meta Platforms|Meta]] (formerly Facebook) and a community of individual developers and companies.<ref>{{cite web |last=Krill |first=Paul |date=May 15, 2014 |title=React: Making faster, smoother UIs for data-driven Web apps |url=https://www.infoworld.com/article/2608181/javascript/react--making-faster--smoother-uis-for-data-driven-web-apps.html |access-date=2021-02-23 |website=[[InfoWorld]] |archive-date=2018-06-12 |archive-url=https://web.archive.org/web/20180612141516/https://www.infoworld.com/article/2608181/javascript/react--making-faster--smoother-uis-for-data-driven-web-apps.html |url-status=live }}</ref><ref>{{cite web |last=Hemel |first=Zef |date=June 3, 2013 |title=Facebook's React JavaScript User Interfaces Library Receives Mixed Reviews |url=https://www.infoq.com/news/2013/06/facebook-react |url-status=live |access-date=2022-01-11 |website=infoq.com |language=en-US |archive-url=https://web.archive.org/web/20220526082114/https://www.infoq.com/news/2013/06/facebook-react/ |archive-date=May 26, 2022}}</ref><ref>{{cite web |last=Dawson |first=Chris |date=July 25, 2014 |title=JavaScript's History and How it Led To ReactJS |url=https://thenewstack.io/javascripts-history-and-how-it-led-to-reactjs/ |url-status=live |access-date=2020-07-19 |website=The New Stack |language=en-US |archive-url=https://web.archive.org/web/20200806190027/https://thenewstack.io/javascripts-history-and-how-it-led-to-reactjs/ |archive-date=Aug 6, 2020 }}</ref>
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>
=== 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,
<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
Line 54 ⟶ 55:
}}</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 ====
Line 77 ⟶ 78:
</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 ===
Line 100 ⟶ 102:
=== Virtual 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
==== 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>
Line 117 ⟶ 119:
=== 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]].
An example of JSX code:
<syntaxhighlight lang="jsx">
function Example() {
// Declare a new state variable, which we'll call "count"
const [count, setCount] = useState(0);
return (▼
<div>▼
<button onClick={() => setCount(count + 1)}>
</div>▼
}▼
}
</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 ===
Line 191 ⟶ 195:
=== 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>
Line 199 ⟶ 204:
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 [[
== History ==
| |||