chalk/readme.md at d16b0ce3677f33bb67ee9cdf7a2bb8795eb60e04

Joshua Appelman d16b0ce367 Adds support for nested chalk expressions.

green(a + blue(b) + c) will now look the same as green(a) +
blue(b) + green(c), as expected. In the previous implementation the
output would have been green(a) + blue(b) + c, because the reset code of
the second expression would close all expressions around it as well.

Now this reset code is replaced by a start code of the outer lying
expression, both stopping the inner and re-starting the outer.

2014-06-23 13:25:47 +02:00

3.9 KiB

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Terminal string styling done right

colors.js is currently the most popular string styling module, but it has serious deficiencies like extending String.prototype which causes all kinds of problems. Although there are other ones, they either do too much or not enough.

Chalk is a clean and focused alternative.

Why

Doesn't extend String.prototype
Expressive API
Clean and focused
Auto-detects color support
Actively maintained
Used by 1000+ modules

Install

$ npm install --save chalk

Usage

Chalk comes with an easy to use composable API where you just chain and nest the styles you want.

var chalk = require('chalk');

// style a string
console.log(  chalk.blue('Hello world!')  );

// combine styled and normal strings
console.log(  chalk.blue('Hello'), 'World' + chalk.red('!')  );

// compose multiple styles using the chainable API
console.log(  chalk.blue.bgRed.bold('Hello world!')  );

// nest styles
console.log(  chalk.red('Hello', chalk.underline.bgBlue('world') + '!')  );

// nest styles of the same type even (colour, underline, background)
console.log( chalk.green('Hello, I'm a green line ' + chalk.blue('with a blue substring') + ' that becomes green again!') );

// pass in multiple arguments
console.log(  chalk.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz')  );

Easily define your own themes.

var chalk = require('chalk');
var error = chalk.bold.red;
console.log(error('Error!'));

Take advantage of console.log string substitution.

var name = 'Sindre';
console.log(chalk.green('Hello %s'), name);
//=> Hello Sindre

API

chalk.`<style>[.<style>...](string, [string...])`

Example: chalk.red.bold.underline('Hello', 'world');

Chain styles and call the last one as a method with a string argument. Order doesn't matter.

Multiple arguments will be separated by space.

chalk.enabled

Color support is automatically detected, but you can override it.

chalk.supportsColor

Detect whether the terminal supports color.

Can be overridden by the user with the flags --color and --no-color.

Used internally and handled for you, but exposed for convenience.

chalk.styles

Exposes the styles as ANSI escape codes.

Generally not useful, but you might need just the .open or .close escape code if you're mixing externally styled strings with yours.

var chalk = require('chalk');

console.log(chalk.styles.red);
//=> {open: '\u001b[31m', close: '\u001b[39m'}

console.log(chalk.styles.red.open + 'Hello' + chalk.styles.red.close);

chalk.stripColor(string)

Strip color from a string.

Can be useful in combination with .supportsColor to strip color on externally styled text when it's not supported.

Example:

var chalk = require('chalk');
var styledString = getText();

if (!chalk.supportsColor) {
	styledString = chalk.stripColor(styledString);
}

Styles

General

reset
bold
dim
italic (not widely supported)
underline
inverse
hidden
strikethrough (not widely supported)

Text colors

black
red
green
yellow
blue
magenta
cyan
white
gray

Background colors

bgBlack
bgRed
bgGreen
bgYellow
bgBlue
bgMagenta
bgCyan
bgWhite

3.9 KiB Raw Blame History

Why