A production-focused playground for live editing React components

Oct 16, 2018
A production-focused playground for live editing React components

React Live

A production-focused playground for live editing React code.

React Live brings you the ability to render React components and present the user with editable source code and live preview. It supports server-side rendering and comes in a tiny bundle, thanks to Bublé and a Prism.js-based editor.

The library is structured modularly and lets you style its components as you wish and put them where you want.

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Install it with npm install react-live and try out this piece of JSX:

import { LiveProvider, LiveEditor, LiveError, LivePreview } from 'react-live' <LiveProvider code="<strong>Hello World!</strong>"> <LiveEditor /> <LiveError /> <LivePreview /> </LiveProvider>


How does it work?

It takes your code and transpiles it through Bublé, while the code is displayed using Prism.js.
The transpiled code is then rendered in the preview component, which does a fake mount, if the code
is a component.

Easy peasy!

What code can I use?

The code can be one of the following things:

  • React elements, e.g. <strong>Hello World!</strong>
  • React pure functional components, e.g. () => <strong>Hello World!</strong>
  • React component classes

If you enable the noInline prop on your LiveProvider, you’ll be able to write imperative code,
and render one of the above things by calling render.

How does the scope work?

The scope prop on the LiveProvider accepts additional globals. By default it injects React only, which
means that the user can use it in their code like this:

// ↓↓↓↓↓ class Example extends React.Component { render() { return <strong>Hello World!</strong> } }

But you can of course pass more things to this scope, that will be available as variables in the code. Here's an example using styled components:

import styled from 'styled-components'; const headerProps = { text: 'I\'m styled!' }; const scope = {styled, headerProps}; const code = ` const Header = styled.div\` color: palevioletred; font-size: 18px; \` render(<Header>{headerProps.text}</Header>) ` <LiveProvider code={code} scope={scope} noInline={true}> <LiveEditor /> <LiveError /> <LivePreview /> </LiveProvider>


This component provides the context for all the other ones. It also transpiles the user’s code!
It supports these props, while passing all others through to a <div />:

codePropTypes.stringThe code that should be rendered, apart from the user’s edits
scopePropTypes.objectAccepts custom globals that the code can use
mountStylesheetPropTypes.boolMounts the stylesheet for the prism editor (Default: true)
noInlinePropTypes.boolDoesn’t evaluate and mount the inline code (Default: false)
transformCodePropTypes.funcAccepts and returns the code to be transpiled, affording an opportunity to first transform it.

Apart from these props it attaches the .react-live CSS class to its div.
All subsequent components must be rendered inside a provider, since they communicate
using one.

By default this component will render a <style /> tag for the Prism styling. You can decide not
to render it and include the react-live.css file instead.

The noInline option kicks the Provider into a different mode, where you can write imperative-style
code and nothing gets evaluated and mounted automatically. Your example will need to call render
with valid JSX elements.

This component renders the editor that displays the code. It is built using Prism.js and a Content Editable.
It accepts these props for styling:

classNamePropTypes.stringAn additional class that is added to the Content Editable
ignoreTabKeyPropTypes.boolMakes the editor ignore tab key presses so that keyboard users can tab past the editor without getting stuck
stylePropTypes.objectAdditional styles for the Content Editable
onChangePropTypes.funcAccepts a callback that is called when the user makes changes

This component renders a Prism.js editor underneath it and also renders all of Prism’s
styles inside a style tag.
The editor / content editable has an additional .react-live-editor CSS class.

This component renders any error that occur while executing the code, or transpiling it.
It passes through any props to its div and also attaches the .react-live-error CSS class to it.

Note: Right now the component unmounts, when there’s no error to be shown.

This component renders the actual component, that the code generates, inside an error boundary.
It passes through any props to its div and also attaches the .react-live-preview CSS class to it.


The withLive method creates a higher-order component, that injects the live-editing context provided
by LiveProvider into a component, as the live prop.

The context's shape is as follows:

codestringReflects the code that is passed in as the code prop
errorstringAn error that the code has thrown when it was previewed
onErrorfunctionA callback that, when called, changes the error to what's passed as the first argument
onChangefunctionA callback that accepts new code and transpiles it
elementReact.ElementThe result of the transpiled code that is previewed

Note: The code prop doesn't reflect the up-to-date code, but the code prop, that is passed to the LiveProvider.
This is due to the fact that the Editor is an uncontrolled input for the reason of managing the contentEditable
element efficiently.

Using this HOC allows you to add new components to react-live, or replace the default ones, with a new
desired behaviour.