Drop-dead simple keypress event emitter for Node.js. Create powerful CLI applications and experiences with ease.
Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your ❤️ and support.
Install with npm:
$ npm install --save emit-keypressNode's built-in readline module is great for handling user input if you need something simple. But when using createInterface, there are a number of built-in behaviors that are difficult or impossible to override when you need more control over the input stream.
Other keypress modules I found either did too much, or didn't allow for enough customization. This module is designed to be simple, flexible, easy to use, and easy to customize.
Create your own CLI interface
It's lightweight, no dependencies, easy to use, and easy to customize. It's designed to be used in a wide range of use-cases, from simple command-line utilities to complex terminal applications.
Powerful CLI applications can be built with this module.
import { emitKeypress } from 'emit-keypress';
emitKeypress({ input: process.stdin });
process.stdin.on('keypress', (input, key) => {
console.log({ input, key });
if (input === '\x03' || input === '\r') {
process.stdin.pause();
}
});Pass an onKeypress function to emitKeypress to handle keypress events.
// The "close" function is passed as the third argument
const onKeypress = async (input, key, close) => {
// do stuff with keypress events
console.log({ input, key });
// Close the stream if the user presses `Ctrl+C` or `Enter`
if (input === '\x03' || input === '\r') {
close();
}
};
emitKeypress({ onKeypress });A close function is also returned from emitKeypress that can be called to close the stream.
const { close } = emitKeypress({ onKeypress });
// close the stream
setTimeout(() => {
close();
}, 10_000);Pass a keymap array to map keypress events to specific shortcuts.
emitKeypress({
keymap: [
{ sequence: '\x03', shortcut: 'ctrl+c' },
{ sequence: '\r', shortcut: 'return' }
],
onKeypress: async (input, key, close) => {
// do stuff with keypress events
console.log({ input, key });
if (key.shortcut === 'return' || key.shortcut === 'ctrl+c') {
close();
}
}
});Note that you can add arbitrary properties the keymap objects. This is useful for mapping shortcuts to commands.
Example
emitKeypress({
keymap: [
{ sequence: '\x1B', shortcut: 'escape', command: 'cancel' },
{ sequence: '\x03', shortcut: 'ctrl+c', command: 'cancel' },
{ sequence: '\r', shortcut: 'return', command: 'submit' }
],
onKeypress: async (input, key, close) => {
// do stuff with keypress events
switch (key.command) {
case 'cancel':
console.log('canceled');
close();
break;
case 'submit':
console.log('submitted');
break;
}
}
});Pass a ReadableStream to input to listen for keypress events on the stream.
emitKeypress({
input: process.stdin,
onKeypress: async (input, key, close) => {
// do stuff with keypress events
console.log({ input, key });
if (key.shortcut === 'return' || key.shortcut === 'ctrl+c') {
close();
}
}
});Contributing
Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.
Running Tests
Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:
$ npm install && npm testBuilding docs
(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)
To generate the readme, run the following command:
$ npm install -g verbose/verb#dev verb-generate-readme && verbJon Schlinkert
Copyright © 2024, Jon Schlinkert. Released under the MIT License.
This file was generated by verb-generate-readme, v0.8.0, on October 27, 2024.