react / Component

Class: Component<P, S, SS>#

Extends#

• ComponentLifecycle<P, S, SS>

Extended by#

• PureComponent

Type Parameters#

Constructors#

new Component()#

new Component<P, S, SS>(props: P): Component<P, S, SS>

Parameters#

Returns#

Component<P, S, SS>

Inherited from#

ComponentLifecycle<P, S, SS>.constructor

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1009

new Component()#

new Component<P, S, SS>(props: P, context: any): Component<P, S, SS>

Parameters#

Returns#

Component<P, S, SS>

Deprecated#

See#

React Docs

Inherited from#

ComponentLifecycle<P, S, SS>.constructor

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1014

Properties#

context#

context: unknown;

If using the new style context, re-declare this in your class to be the React.ContextType of your static contextType. Should be used with type annotation or static contextType.

Example#

static contextType = MyContext
// For TS pre-3.7:
context!: React.ContextType<typeof MyContext>
// For TS 3.7 and above:
declare context: React.ContextType<typeof MyContext>

See#

React Docs

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1007

props#

readonly props: Readonly<P>;

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1027

refs#

refs: object;

Index Signature#

[key: string]: ReactInstance

Deprecated#

See#

Legacy React Docs

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1034

state#

state: Readonly<S>;

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1028

contextType?#

static optional contextType: Context<any>;

If set, this.context will be set at runtime to the current value of the given Context.

Example#

type MyContext = number
const Ctx = React.createContext<MyContext>(0)

class Foo extends React.Component {
  static contextType = Ctx
  context!: React.ContextType<typeof Ctx>
  render () {
    return <>My context's value: {this.context}</>;
  }
}

See#

https://react.dev/reference/react/Component#static-contexttype

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:989

Methods#

componentDidCatch()?#

optional componentDidCatch(error: Error, errorInfo: ErrorInfo): void

Catches exceptions generated in descendant components. Unhandled exceptions will cause the entire component tree to unmount.

Parameters#

Returns#

void

Inherited from#

ComponentLifecycle.componentDidCatch

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1391

componentDidMount()?#

optional componentDidMount(): void

Called immediately after a component is mounted. Setting state here will trigger re-rendering.

Returns#

void

Inherited from#

ComponentLifecycle.componentDidMount

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1370

componentDidUpdate()?#

optional componentDidUpdate(
   prevProps: Readonly<P>,
   prevState: Readonly<S>,
   snapshot?: SS): void

Called immediately after updating occurs. Not called for the initial render.

The snapshot is only present if getSnapshotBeforeUpdate is present and returns non-null.

Parameters#

Returns#

void

Inherited from#

ComponentLifecycle.componentDidUpdate

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1433

componentWillMount()?#

optional componentWillMount(): void

Called immediately before mounting occurs, and before Component.render. Avoid introducing any side-effects or subscriptions in this method.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

Returns#

void

Deprecated#

16.3, use ComponentLifecycle.componentDidMount componentDidMount or the constructor instead; will stop working in React 17

See#

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#initializing-state
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

Inherited from#

ComponentLifecycle.componentWillMount

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1449

componentWillReceiveProps()?#

optional componentWillReceiveProps(nextProps: Readonly<P>, nextContext: any): void

Called when the component may be receiving new props. React may call this even if props have not changed, so be sure to compare new and existing props if you only want to handle changes.

Calling Component.setState generally does not trigger this method.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

Parameters#

Returns#

void

Deprecated#

16.3, use static StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps instead; will stop working in React 17

See#

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#updating-state-based-on-props
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

Inherited from#

ComponentLifecycle.componentWillReceiveProps

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1480

componentWillUnmount()?#

optional componentWillUnmount(): void

Called immediately before a component is destroyed. Perform any necessary cleanup in this method, such as cancelled network requests, or cleaning up any elements created in componentDidMount.

Returns#

void

Inherited from#

ComponentLifecycle.componentWillUnmount

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1386

componentWillUpdate()?#

optional componentWillUpdate(
   nextProps: Readonly<P>,
   nextState: Readonly<S>,
   nextContext: any): void

Called immediately before rendering when new props or state is received. Not called for the initial render.

Note: You cannot call Component.setState here.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

Parameters#

Returns#

void

Deprecated#

16.3, use getSnapshotBeforeUpdate instead; will stop working in React 17

See#

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#reading-dom-properties-before-an-update
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

Inherited from#

ComponentLifecycle.componentWillUpdate

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1512

forceUpdate()#

forceUpdate(callback?: () => void): void

Parameters#

Returns#

void

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1024

getSnapshotBeforeUpdate()?#

optional getSnapshotBeforeUpdate(prevProps: Readonly<P>, prevState: Readonly<S>): null | SS

Runs before React applies the result of render to the document, and returns an object to be given to componentDidUpdate. Useful for saving things such as scroll position before render causes changes to it.

Note: the presence of this method prevents any of the deprecated lifecycle events from running.

Parameters#

Returns#

null | SS

Inherited from#

ComponentLifecycle.getSnapshotBeforeUpdate

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1427

render()#

render(): ReactNode

Returns#

ReactNode

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1025

setState()#

setState<K>(state: null | S | (prevState: Readonly<S>, props: Readonly<P>) => null | S | Pick<S, K> | Pick<S, K>, callback?: () => void): void

Type Parameters#

Parameters#

Returns#

void

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1019

shouldComponentUpdate()?#

optional shouldComponentUpdate(
   nextProps: Readonly<P>,
   nextState: Readonly<S>,
   nextContext: any): boolean

Called to determine whether the change in props and state should trigger a re-render.

Component always returns true. PureComponent implements a shallow comparison on props and state and returns true if any props or states have changed.

If false is returned, Component.render, componentWillUpdate and componentDidUpdate will not be called.

Parameters#

Returns#

boolean

Inherited from#

ComponentLifecycle.shouldComponentUpdate

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1381

UNSAFE_componentWillMount()?#

optional UNSAFE_componentWillMount(): void

Called immediately before mounting occurs, and before Component.render. Avoid introducing any side-effects or subscriptions in this method.

This method will not stop working in React 17.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

Returns#

void

Deprecated#

16.3, use ComponentLifecycle.componentDidMount componentDidMount or the constructor instead

See#

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#initializing-state
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

Inherited from#

ComponentLifecycle.UNSAFE_componentWillMount

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1464

UNSAFE_componentWillReceiveProps()?#

optional UNSAFE_componentWillReceiveProps(nextProps: Readonly<P>, nextContext: any): void

Called when the component may be receiving new props. React may call this even if props have not changed, so be sure to compare new and existing props if you only want to handle changes.

Calling Component.setState generally does not trigger this method.

This method will not stop working in React 17.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

Parameters#

Returns#

void

Deprecated#

16.3, use static StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps instead

See#

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#updating-state-based-on-props
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

Inherited from#

ComponentLifecycle.UNSAFE_componentWillReceiveProps

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1498

UNSAFE_componentWillUpdate()?#

optional UNSAFE_componentWillUpdate(
   nextProps: Readonly<P>,
   nextState: Readonly<S>,
   nextContext: any): void

Called immediately before rendering when new props or state is received. Not called for the initial render.

Note: You cannot call Component.setState here.

This method will not stop working in React 17.

Note: the presence of NewLifecycle.getSnapshotBeforeUpdate getSnapshotBeforeUpdate or StaticLifecycle.getDerivedStateFromProps getDerivedStateFromProps prevents this from being invoked.

Parameters#

Returns#

void

Deprecated#

16.3, use getSnapshotBeforeUpdate instead

See#

• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#reading-dom-properties-before-an-update
• https://legacy.reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path

Inherited from#

ComponentLifecycle.UNSAFE_componentWillUpdate

Defined in#

.pnpm/@types+react@18.3.11/node_modules/@types/react/ts5.0/index.d.ts:1528