@pobedit/kefir

A BEM friendly class name generator.

Installation

Install with npm or Yarn:

npm:

npm install @pobedit/kefir --save

Yarn:

yarn add @pobedit/kefir

Basic usage

We have a wide variety of semantically correct BEM rules:

import {$} from '@pobedit/kefir';

$('foo', 'bar');
// foo__bar

$('foo', {bar: true});
// foo foo--bar

$('foo', 'bar', {baz: true});
 // foo__bar foo__bar--baz

$('foo', {bar: true}, ['baz']);
 // foo foo--bar baz

$('foo', ['bar']);
 // foo bar

$('foo', 'bar', ['baz', 'gaz']);
 // foo__bar baz gaz

$('foo', 'bar', {baz: true}, ['taz']);
 // foo__bar foo__bar--baz taz

React usage

import React, {ReactNode, useState} from 'react';
import {$} from '@pobedit/kefir';

type Props = {
   bar: boolean
}

export const Example: React.FunctionComponent<Props> = (props) => {
   const {bar} = props;

   return (
       <div className={$('foo', 'container', {bar})}>
           <button className={$('button', { baz })}>
               Click!
           </button>
       </div>
   );
};

Output:

<div class="foo__container foo__container--bar">
    <button class="button button--baz">Click</button>>
</div>

So, your CSS structure looks like:

.foo {
  &__container {
      &--bar {
        background-color: red;
      }
  }
}

.button {
  &--baz {
    color: white;
  }
}

API

Parameters

Name	Type	Description
block	string	Encapsulates a standalone entity that is meaningful on its own.
element	string	Parts of a block and have no standalone meaning.
modifiers	object	Flags on blocks or elements.
extra	string[]	A set of additional classes.

$

$ is a highly polymorphic function with the following interfaces:

Block

import {$} from '@pobedit/kefir';

$('foo');
 // foo

Element

import {$} from '@pobedit/kefir';

$('foo', 'bar');
 // foo__bar

$('foo', 'bar', ['baz', 'gaz']);
 // foo__bar baz gaz

$('foo', 'bar', {baz: true});
 // foo__bar foo__bar--baz

$('foo', 'bar', {baz: true, gaz: true}, ['taz']);
 // foo__bar foo__bar--baz foo__bar--gaz taz

Modifier

import {$} from '@pobedit/kefir';

$('foo', {bar: true});
 // foo foo--bar

$('foo', {bar: true, gaz: true}, ['baz']);
 // foo foo--bar foo--gar baz

$('foo', ['bar']);
 // foo bar

API

Kefir

It's just a wrapper around the main function $:

import {$} from '@pobedit/kefir';

let $ = kefir('foo');

$({bar: true});
 // foo foo--bar

The second example of advanced usage:

import React, {ReactNode, useState} from 'react';
import {kefir} from '@pobedit/kefir';

type Props = {
   bar: boolean;
   baz: boolean;
}

export const Example: React.FunctionComponent<Props> = (props) => {
   const {bar, baz} = props;
   let $ = kefir('foo');

   return (
       <div className={$('container', { bar })}>
           <button className={$('button', { baz })}>
               Click!
           </button>
       </div>
   );
};

Output:

<div class="foo__container foo__container--bar">
    <button class="button button--baz">Click</button>>
</div>

Contributing

Feel free to submit a pull request if you find any bugs. Please make sure all commits are properly documented.

Tests

npm test

Publishing

npm publish --access public --verbose

License

MIT