Playground

A simple playground for HTML, CSS and JavaScript supporting module imports.

Playground is a HTML, CSS and JS demonstration component that runs entirely in the browser and does not require loading any third party sites.

Usage

Install from npm with:

npm install @agney/playground
# OR
yarn add @agney/playground

import Playground from "@agney/playground";
/* Why is there a tabs import? https://github.com/agneym/playground#why-is-there-a-reacttabs-import*/
import "@reach/tabs/styles.css";

const App = () => {
  const snippet = {
    markup: `<div id=app />`,
    css: ``,
    javascript: `import { h, Component, render } from 'preact';
import htm from 'htm';

const html = htm.bind(h);

const app = html\`<div>Hello World from Playground!</div>\`

render(app, document.getElementById('app'));`,
  };
  return (
    <Playground
      id="example"
      initialSnippet={snippet}
      defaultEditorTab="javascript"
      transformJs
    />
  );
};

Demo

https://blog.agney.dev/introducing-playground/

Features

1. Load preview for predefined code.
2. Autoreloading preview.
3. Allows bare ES package imports. This means you can add imports for any library that supports ES Module resolution and playground will automatically load it into your code.
4. See console output in the component itself.
5. Control the tab loaded by default for your use-case.

Applications

1. Add to static blogs to present your HTML, CSS or JavaScript code.
2. Allow users to change the code and see the output in real time.

API

Props	description	default	required
id	a unique identifier for the iFrame		true
initialSnippet	Initial code to be displayed		true
defaultEditorTab	Initial editor tab to be displyed. Possible values: "markup", "css", "javascript"	"markup"	false
defaultResultTab	Initial tab on result panel to be displayed. Possible values: "console", "result"	"result"	false
transformJs	Transform the JavaScript using Babel. This is required if you want bare module imports	false	false
presets	Array of presets you want Babel to transform. This works only if transformJs is true. Eg. ["react", "es2015"]		false
theme	Pass in the theme variables to customise the appearance	Our Theme	false

Format for initial snippet

{
  markup: `<h1>Title</h1>`,
  css: `h1 { color: red }`,
  javascript: `console.log("this")`
}

Why is there a @react/tabs import?

Playground uses @reach/tabs as a dependency. We could bundle the stylesheet or inject it inline on runtime. But both those options add unnecessary code if you are already using it.

This might cause breaking changes if you have a different version of @reach/tabs but then I'm just expecting it to be stable along the road.

How does module imports work?

If an NPM package exposes an endpoint for "module", then you can direcly import this package by it's name.

import { format } from "date-fns";

format(new Date(2014, 1, 11), "yyyy-MM-dd");

Unfortunately, not all packages currently support this feature. You can search through an entire list of packages through Skypack.

You can use community created packages to replicate the functionality. For eg. React would be:

import React, { createElement } from "https://cdn.skypack.dev/react";
import ReactDOM from "https://cdn.skypack.dev/react-dom";

ReactDOM.render(
  createElement("div", {}, "Hello World"),
  document.getElementById("app")
);

How do I demo React code with JSX?

import Playground from "@agney/playground";

const App = () => {
  const snippet = {
    markup: `<div id=app />`,
    css: ``,
    javascript: `import React, { createElement } from "https://cdn.skypack.dev/react";
import ReactDOM from "https://cdn.skypack.dev/react-dom";

ReactDOM.render(
  <h1>Hello World</h1>,
  document.getElementById("app")
);`,
  };
  return (
    <Playground
      initialSnippet={snippet}
      defaultEditorTab="javascript"
      transformJs
      presets={["react"]}
    />
  );
};

What about the bundle size?

The component is fairly small at about . You can find the total size and time on Bundle Phobia.

When transforming JavaScript it uses Babel Standalone which adds a considerable size. Playground loads Babel from a CDN so that it can be loaded from browser cache on change.

It uses Chrome's Native Lazy Loading so that the iframes for results are loaded lazily and your pages remain fast.

Contributing

This project makes use of Yarn Workspaces for development.

1. Run yarn for installing dependencies.

2. Run yarn start to start development on package.

3. To start example, run yarn start-example.

Pull Requests are Welcome. Please create an issue to discuss before making a feature or large change. Thank You 😄

Credits

Icons made by Freepik from www.flaticon.com