| # `react-is` | |
| This package allows you to test arbitrary values and see if they're a particular React element type. | |
| ## Installation | |
| ```sh | |
| # Yarn | |
| yarn add react-is | |
| # NPM | |
| npm install react-is | |
| ``` | |
| ## Usage | |
| ### Determining if a Component is Valid | |
| ```js | |
| import React from "react"; | |
| import * as ReactIs from "react-is"; | |
| class ClassComponent extends React.Component { | |
| render() { | |
| return React.createElement("div"); | |
| } | |
| } | |
| const FunctionComponent = () => React.createElement("div"); | |
| const ForwardRefComponent = React.forwardRef((props, ref) => | |
| React.createElement(Component, { forwardedRef: ref, ...props }) | |
| ); | |
| const Context = React.createContext(false); | |
| ReactIs.isValidElementType("div"); // true | |
| ReactIs.isValidElementType(ClassComponent); // true | |
| ReactIs.isValidElementType(FunctionComponent); // true | |
| ReactIs.isValidElementType(ForwardRefComponent); // true | |
| ReactIs.isValidElementType(Context.Provider); // true | |
| ReactIs.isValidElementType(Context.Consumer); // true | |
| ReactIs.isValidElementType(React.createFactory("div")); // true | |
| ``` | |
| ### Determining an Element's Type | |
| #### Context | |
| ```js | |
| import React from "react"; | |
| import * as ReactIs from 'react-is'; | |
| const ThemeContext = React.createContext("blue"); | |
| ReactIs.isContextConsumer(<ThemeContext.Consumer />); // true | |
| ReactIs.isContextProvider(<ThemeContext.Provider />); // true | |
| ReactIs.typeOf(<ThemeContext.Provider />) === ReactIs.ContextProvider; // true | |
| ReactIs.typeOf(<ThemeContext.Consumer />) === ReactIs.ContextConsumer; // true | |
| ``` | |
| #### Element | |
| ```js | |
| import React from "react"; | |
| import * as ReactIs from 'react-is'; | |
| ReactIs.isElement(<div />); // true | |
| ReactIs.typeOf(<div />) === ReactIs.Element; // true | |
| ``` | |
| #### Fragment | |
| ```js | |
| import React from "react"; | |
| import * as ReactIs from 'react-is'; | |
| ReactIs.isFragment(<></>); // true | |
| ReactIs.typeOf(<></>) === ReactIs.Fragment; // true | |
| ``` | |
| #### Portal | |
| ```js | |
| import React from "react"; | |
| import ReactDOM from "react-dom"; | |
| import * as ReactIs from 'react-is'; | |
| const div = document.createElement("div"); | |
| const portal = ReactDOM.createPortal(<div />, div); | |
| ReactIs.isPortal(portal); // true | |
| ReactIs.typeOf(portal) === ReactIs.Portal; // true | |
| ``` | |
| #### StrictMode | |
| ```js | |
| import React from "react"; | |
| import * as ReactIs from 'react-is'; | |
| ReactIs.isStrictMode(<React.StrictMode />); // true | |
| ReactIs.typeOf(<React.StrictMode />) === ReactIs.StrictMode; // true | |
| ``` | |