Carlo - headful Node app framework

Carlo provides Node applications with the rich rendering capabilities powered by the Google Chrome browser. It uses Puppeteer project to communicate with the locally installed browser instance, provides remote call infrastructure for communication between Node and the browser.

FAQ | Contributing

What can I do?

With Carlo, you can create hybrid applications that use Web stack for rendering and Node for capabilities:

For Node applications, you can visualize dynamic state of your Node app using web rendering stack
For Web applications, you can expose additional system capabilities accessible from Node
Bundle your application into a single executable using pkg.

How does it work?

Carlo locates Google Chrome installed locally
Launches it and establishes connection to Chrome over the process pipe
Exposes high level API for rendering in Chrome in Node environment
Carlo is based on the Puppeteer project

Getting Started

Installation

To use Carlo in your project, run:

npm i carlo
# or "yarn add carlo"

Usage

Note: Carlo requires at least Node v7.6.0.

Example - Visualize local environment:

Save file as example.js

const carlo = require('carlo');

(async () => {
  const app = await carlo.launch();
  app.serveFolder(__dirname);
  await app.exposeFunction('env', _ => process.env);
  await app.load('example.html');
})();

Save file as example.html

<script>
async function run() {
  const data = await env();
  for (const type in data) {
    const div = document.createElement('div');
    div.textContent = `${type}: ${data[type]}`;
    document.body.appendChild(div);
  }
}
</script>
<body onload="run()">

Execute script on the command line

node example.js

Check out more examples with richer UI and RPC-based communication between the Web and Node components under the examples folder.

Contributing to Carlo

Check out contributing guide to get an overview of Carlo development.

FAQ

Q: What was the motivation behind this project when we already have Electron and NW.js? How this differs from these platforms, how it helps to achieve something that's not possible/harder with these two?

One of the motivations is to demonstrate how browser installed locally can be used with Node out of the box.
Unlike with Electron, Node v8 and Chrome v8 engines are decoupled in Carlo, providing a maintainable model with the ability of the independent updates of the underlying components. Carlo is less about branding and is more about productivity + giving the control over bundling to the user.

Q: Can Node app using Carlo be packaged as a Desktop app?

One can use the pkg project to package their Node app as a Desktop app. Carlo does not provide the branding configurability such as application icon or customizable menus, it focuses on the productivity and Web/Node interoperability instead. Check out the systeminfo example and call pkg package.json in it to see how it works.

Q: What happens if the user does not have Chrome installed?

Carlo prints error message when it can't locate Chrome.

Q: What is the minimum Chrome version that Carlo supports?

Chrome Stable channel, versions 70.* are supported.

xat/carlo