tailwind-classlist

This library provides a few utility functions to simplify use of TailwindCSS in Javascript. Its primary purpose is to make it easier to create and combine className strings in JSX.

This repository follows semver versioning and any versions prior to 1.x.x are liable to experience changes in later releases and contain bugs.

Note: This library no longer supports versions of Tailwind <1.0.

Methods

classList

The classList method accepts an object that defines the TailwindCSS classes that you wish to use. It converts this object into a string of classnames.

For basic cases, you simply provide an object where the keys are the part of a Tailwind class before the first -. For example, text-center would be represented by { text: 'center' } and bg-blue-darker would be represented by { bg: 'blue-darker' }.

import { classList } from 'tailwind-classlist';

const classes = classList({
  m: 2,
  cursor: 'pointer',
  bg: 'grey-400',
});

// Outputs "m-2 cursor-pointer bg-grey-400"

To use multiple classes with the same Tailwind prefix, group them together into an array.

const classes = classList({
  text: ['lg', 'grey-600']
});

// Outputs "text-lg text-grey-600"

To use state variants and responsive prefixes, group them together into an object.

const classes = classList({
  bg: 'white',
  text: 'red-400',
  hover: { 
  	bg: 'red-400', 
  	text: 'white',
  },
  focus: {
  	outline: 'none',
  },
  md: {
  	text: 'lg',
  }
});

// Outputs "bg-white text-red-400 hover:bg-red-400 hover:text-white focus:outline-none"

To use both state variants and responsive prefixes, use a nested object that begins with the responsive prefix first.

const classes = classlist({
  md: {
  	hover: {
  		bg: 'red-800',
  		text: 'blue-400',
  	}
  }  
});

// Outputs "md:hover:bg-red-800 md:hover:text-blue-400"

Some classes in Tailwind don't have any dashes in their name. These can be included by setting their value to true.

const classes = classList({
  fixed: true,
  italic: true,
});

// Outputs "fixed italic"

mergeClassLists

The mergeClassLists method accepts 2 or more classList strings and merges them together, overwriting any conflicting classes as it goes.

import { mergeClassLists } from 'tailwind-classlist';

const classListA = 'bg-blue-500 m-4';
const classListB = 'bg-red-500 p-4';
const combinedClasses = mergeClassLists(classListA, classListB); 

// Outputs 'bg-red-500 m-4 p-4'

It recognizes when multiple classes have the same prefix but shouldn't overwrite eachother. In the example below, bg-red overwrites bg-blue, but it has no effect on bg-bottom.

const classListA = 'bg-blue-500 bg-bottom m-4';
const classListB = 'bg-red-500 p-4';
const combinedClasses = mergeClassLists(classListA, classListB);

// Outputs 'bg-red-500 bg-bottom m-4 p-4';

Similarly, it recognizes classes with conflicting styles that don't have the same prefix. In the example below, static and fixed both affect the position CSS property, so fixed will overwrite static.

const classListA = 'bg-blue-500 bg-bottom text-xs m-4 static';
const classListB = 'bg-red-500 p-4 text-lg fixed';
const result = mergeClassLists(classListA, classListB);

// Outputs 'bg-red-500 bg-bottom text-lg m-4 p-4 fixed'

Any classes that aren't part of the default Tailwind library will pass through without any filtering.

const classListA = 'bg-blue-500 text-xs sc-0dWm9Vdw2';
const classListB = 'bg-red-500 fixed test-class';
const result = mergeClassLists(classListA, classListB);

// Outputs 'sc-0dWm9Vdw2 test-class bg-red-500 text-xs fixed'

parseClassList

The parseClassList method performs the opposite operation as classList. It takes a string of classnames and returns a parsed classList object. Any classes that aren't a part of the default Tailwind library will be grouped into an array under the key extraKeys.

import { parseClassList } from 'tailwind-classlist';

const classes = 'm-2 cursor-pointer bg-grey-400';
const classObj = parseClassList(classes);
// Outputs { m: 2, cursor: 'pointer', bg: 'grey-400' };

const classes = 'm-2 cursor-pointer sc-8d3jd6Ko customclass';
const classObj = parseClassList(classes);
// Outputs { m: 2, cursor: 'pointer', extraClasses: ['sc-8d3jd6Ko', 'customclass'] };