Carlo provides Node applications with Google Chrome rendering capabilities. Carlo communicates with the locally-installed browser instance using the Puppeteer project. Carlo also provides remote call infrastructure for communication between Node and the browser.
API | FAQ | Contributing
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
- You can bundle your application into a single executable using pkg.
- 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
Install Carlo
npm i carlo
yarn add carlo
Carlo requires at least Node v7.6.0.
Example - Display local environment
Save file as example.js
const carlo = require('carlo');
(async () => {
// Launch the browser.
const app = await carlo.launch();
// Terminate Node.js process on app window closing.
app.on('exit', () => process.exit());
// Tell carlo where your web files are located.
app.serveFolder(__dirname);
// Expose 'env' function in the web environment.
await app.exposeFunction('env', _ => process.env);
// Navigate to the main page of your app.
await app.load('example.html');
})();
Save file as example.html
<script>
async function run() {
// Call the function that was exposed in Node.
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()">
Run your application:
node example.js
Check out systeminfo and terminal examples with richer UI and RPC-based communication between the Web and Node under the examples folder.
Check out API to get familiar with Carlo API.
Check out contributing guide to get an overview of Carlo development.
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.
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.
Carlo prints error message when it can't locate Chrome.
Chrome Stable channel, versions 70.* are supported.