https://github.com/jamiebuilds/create-react-context

Polyfill for the proposed React context API
https://github.com/jamiebuilds/create-react-context

context contexttypes polyfill react

Last synced: about 2 months ago
JSON representation

Polyfill for the proposed React context API

• Host: GitHub
• URL: https://github.com/jamiebuilds/create-react-context
• Owner: jamiebuilds
• License: mit
• Created: 2017-12-08T03:45:12.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2021-06-07T04:07:59.000Z (over 3 years ago)
• Last Synced: 2024-05-18T20:06:36.903Z (4 months ago)
• Topics: context, contexttypes, polyfill, react
• Language: JavaScript
• Size: 329 KB
• Stars: 693
• Watchers: 11
• Forks: 74
• Open Issues: 9
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-react-state-management - react-create-context - Polyfill for the proposed React context API. (List)
• awesome-react-context - **react-create-context** - Polyfill for the proposed React context API. (Libraries)

README

        
# create-react-context

> Polyfill for the [proposed React context API](https://github.com/reactjs/rfcs/pull/2)

## Install

```sh

yarn add create-react-context

```

You'll need to also have `react` and `prop-types` installed.

## API

```js

const Context = createReactContext(defaultValue);

// {children}

// ...

// {value => children}

```

## Example

```js

// @flow

import React, { type Node } from 'react';

import createReactContext, { type Context } from 'create-react-context';

type Theme = 'light' | 'dark';

// Pass a default theme to ensure type correctness

const ThemeContext: Context = 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)

      

         {

            this.setState(state => ({

              theme: state.theme === 'light' ? 'dark' : 'light'

            }));

          }}

        >

          Toggle theme

        

        {this.props.children}

      

    );

  }

}

class Title extends React.Component<{ children: Node }> {

  render() {

    return (

      // The Consumer uses a render prop API. Avoids conflicts in the

      // props namespace.

      

        {theme => (

          


            {this.props.children}

          

        )}

      

    );

  }

}

```


## 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

  


  


```

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 `` can only receive a single child element. To fix the error just wrap everyting in a single `
`:


```js

  


    


    


  


```