bem-composer
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    1.0.1 • Public • Published

    BEM composer

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    A easy BEM classname tool for React, styled-components, linaria. Recommend using with classnames.

    Install

    npm

    npm i bem-composer
    

    yarn

    yarn add bem-composer
    

    API

    Output

    import { bem } from 'bem-composer';
    
    // create a `button` block
    const b = bem('button');
    
    console.log(b.toString()); // 'button'
    // shortcut for .toString()
    console.log(b()); // 'button'
    console.log(b.toSelector()); // '.button'
    
    // create a `icon` element based on `b` block
    const e = b('icon');
    
    console.log(e.toString()); // 'button--icon'
    // shortcut for .toString()
    console.log(e()); // 'button--icon'
    console.log(e.toSelector()); // '.button--icon'
    console.log(e.toSuffix()); // '--icon'
    console.log(e.toParentSelector()); // '&--icon'
    
    // create a modifier based on `e` element
    const m = e('active');
    
    console.log(m.toString()); // 'button--icon__active'
    // shortcut for .toString()
    console.log(m().toString()); // 'button--icon__active'
    console.log(m.toSelector().toString()); // '.button--icon__active'
    console.log(m.toSuffix().toString()); // '__active'
    console.log(m.toParentSelector().toString()); // '&__active'
    // get suffix with element
    console.log(m.toSuffix(true).toString()); // '--icon__active'
    // get parent selector with element
    console.log(m.toParentSelector(true).toString()); // '&--icon__active'
    
    // multiple modifiers support
    console.log(m('large')({
      name: 'rounded',
      value: true
    }).toString()); // 'button--icon__active_large_rounded'
    
    // create a modifier with value
    const mv = e({
      name: 'active',
      value: 'hover'
    });
    console.log(mv.toString()); // 'button--icon__active-hover'
    
    // modifier with condition
    console.log(e({
      'active',
      value: false
    }).toString()) // 'button--icon'
    console.log(e({
      'active',
      value: true
    }).toString()) // 'button--icon__active'
    
    // block with modifier
    console.log(b('', 'active').toString()); // 'button_active'
    
    
    

    Configure delimiters

    import { configure, DefaultBEMDelimiters } from 'bem-composer';
    
    // Configure BEM constructor with custom delimiters.
    const cbem = configure({
      prefix: 'bem-',
      element: '__',
      modifier: '~~',
      modifierValue: '~'
    });
    
    console.log(
      cbem('block', 'icon', {
        name: 'active',
        value: 'hover'
      }).toString()
    ); // bem-block__icon~~active~hover

    Curried API

    Provide a curried API to easily create elements and modifiers.

    import { bem } from 'bem-composer';
    
    console.log(bem('button', 'icon').toString()); // button--icon
    console.log(bem('button')('icon').toString()); // button--icon
    console.log(bem('button', 'icon', 'active').toString()); // 'button--icon__active'
    console.log(bem('button')('icon', 'active').toString()); // 'button--icon__active'
    console.log(bem('button', 'icon')('active').toString()); // 'button--icon__active'

    BEM Constructor type definition

    function bem(blockName: string): BEMBlock;
    function bem(blockName: string, elementName: string): BEMElement;
    function bem(
      blockName: string,
      elementName: string,
      modifierValue: BEMModifierValue
    ): BEMModifier;
    
    export type BEMModifierValue =
      | {
          name: string;
          value?: string | boolean;
        }
      | string;
    
    export interface BEMBlock {
      (): string; // shortcut for toString()
      (elementName: string): BEMElement;
      (
        elementName: undefined | string,
        modifierValue: BEMModifierValue
      ): BEMModifier;
      toString: () => string; // Return classname
      toSelector: () => string; // Return classname selector
    }
    
    export interface BEMElement {
      (): string; // shortcut for toString()
      (modifierValue: BEMModifierValue): BEMModifier;
      toString: () => string;
      toSelector: () => string;
      toSuffix: () => string;
      toParentSelector: () => string;
    }
    
    export interface BEMModifier {
      (): string;
      (modifierValue: BEMModifierValue): BEMModifier; // modifier chain, for multiple modifiers support
      toString: () => string;
      toSelector: () => string;
      toSuffix: (withElement?: boolean) => string;
      toParentSelector: (withElement?: boolean) => string;
    }

    React

    import React from 'react';
    import { bem } from 'bem-composer';
    import classNames from 'classnames';
    
    const b = bem('button');
    const e = b('icon');
    const m = e('active');
    
    export default function Button(props) {
      const { active } = props;
      return (
        <button
          classname={classNames([
            b(), // 'button'
            b('', {
              name: 'active',
              value: active
            }) // button__active
          ])}
        >
          <img
            classname={classNames([
              e(), // 'button-icon'
              e({
                name: 'active',
                value: active
              }), // active === true ? 'button--icon__active' : 'button--icon'
              e('primary') // 'button--icon__primary'
            ])}
          />
        </button>
      );
    }

    Styled-components & Linaria

    import styled from 'styled-components';
    
    const b = bem('button');
    const e = b('icon');
    const m = e('active');
    
    export const StyledButton = styled.button`
      /* .button */
      ${b.toSelector()} {
        border: 1px solid red;
        outline: none;
      }
    
      /* &--icon */
      ${e.toParentSelector()} {
        width: 20px;
        height: 20px;
    
        /* &__active */
        ${m.toParentSelector()} {
          opacity: 0.5;
        }
      }
    `;

    Trouble shooting

    Multiple elements support

    As we don't want BEM classname to be too complicated, multiple elements is not provided by this library, but you can do some workaround like this:

    bem('block', 'e1--e2--e3').toString();

    Install

    npm i bem-composer

    DownloadsWeekly Downloads

    83

    Version

    1.0.1

    License

    ISC

    Unpacked Size

    30.3 kB

    Total Files

    33

    Last publish

    Collaborators

    • magicismight