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infrastructure-components

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Infrastructure-Components configure the infrastructure of your React-App as part of your React-Components.

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# mini-create-react-context <p align="center"> <a href="https://packagephobia.now.sh/result?p=mini-create-react-context"> <img alt="npm install size" src="https://packagephobia.now.sh/badge?p=mini-create-react-context"> </a> <a href="https://bundlephobia.com/result?p=mini-create-react-context"> <img alt="npm bundle size" src="https://img.shields.io/bundlephobia/min/mini-create-react-context.svg?style=flat-square"> </a> <a href="https://www.npmjs.com/package/mini-create-react-context"> <img alt="npm" src="https://img.shields.io/npm/v/mini-create-react-context.svg?style=flat-square"> </a> </p> > (A smaller) Polyfill for the [proposed React context API](https://github.com/reactjs/rfcs/pull/2) ## Install ```sh npm install mini-create-react-context ``` You'll need to also have `react` and `prop-types` installed. ## API ```js const Context = createReactContext(defaultValue); /* <Context.Provider value={providedValue}> {children} </Context.Provider> ... <Context.Consumer> {value => children} </Context.Consumer> */ ``` ## Example ```js // @flow import React, { type Node } from 'react'; import createReactContext, { type Context } from 'mini-create-react-context'; type Theme = 'light' | 'dark'; // Pass a default theme to ensure type correctness const ThemeContext: Context<Theme> = createReactContext('light'); class ThemeToggler extends React.Component< { children: Node }, { theme: Theme } > { state = { theme: 'light' }; render() { return ( // Pass the current context value to the Provider's `value` prop. // Changes are detected using strict comparison (Object.is) <ThemeContext.Provider value={this.state.theme}> <button onClick={() => { this.setState(state => ({ theme: state.theme === 'light' ? 'dark' : 'light' })); }} > Toggle theme </button> {this.props.children} </ThemeContext.Provider> ); } } class Title extends React.Component<{ children: Node }> { render() { return ( // The Consumer uses a render prop API. Avoids conflicts in the // props namespace. <ThemeContext.Consumer> {theme => ( <h1 style={{ color: theme === 'light' ? '#000' : '#fff' }}> {this.props.children} </h1> )} </ThemeContext.Consumer> ); } } ``` ## Compatibility This package only "ponyfills" the `React.createContext` API, not other unrelated React 16+ APIs. If you are using a version of React <16, keep in mind that you can only use features available in that version. For example, you cannot pass children types aren't valid pre React 16: ```js <Context.Provider> <div/> <div/> </Context.Provider> ``` It will throw `A valid React element (or null) must be returned. You may have returned undefined, an array or some other invalid object.` because `<Context.Provider>` can only receive a single child element. To fix the error just wrap everyting in a single `<div>`: ```js <Context.Provider> <div> <div/> <div/> </div> </Context.Provider> ```