atrule-bem

Efficiently create BEM components.

Input / Output

Put in:

@block btn {
  background-color: var(--primary);
  border: .0625rem solid var(--primary-constrast);
  color: var(--black);

  @element icon {
    color: var(--primary-contrast-high)
  }

  @modifier transparent {
    background-color: transparent;
    border-color: transparent
  }
}

Get out:

.btn {
    background-color: var(--primary);
    border: .0625rem solid var(--primary-constrast);
    color: var(--black)
}
.btn__icon {
    color: var(--primary-contrast-high)
}
.btn--transparent {
    background-color: transparent;
    border-color: transparent
}

Options

strict

Type: Boolean

Default: true

Disallows improperly formed components

• Block's can only have: Elements and Modifiers.
• Elements can only have Modifiers.
• Modifiers cannot house any types.

Side Effect: turning off strict turns off warnings

warn

Type: Boolean

Default: true

Turns on warnings for imporperly formed components

shortcuts

Type: Boolean

Default: false

separators

Type: Object

Default: { element: '__', modifier: '--' }

Usage

Add atrule-bem to your build tool:

npm install --save-dev postcss-atrule-bem

Node

import atRuleBem from 'postcss-atrule-bem';

atRuleBem.process(/* your css */);

PostCSS

Add PostCSS to your build tool:

npm install postcss --save-dev

Load atrule-bem as a PostCSS plugin:

import atRuleBem from 'postcss-atrule-bem';

postcss([ atRuleBem() ])
.process(/* your css */, /* options */);

Examples

/* you can chain selectors with commas `,` */

/* input: */
@block foo {
  @element bar, baz {}
}

/* output: */
.foo {}
.foo__bar, .foo__baz {}

Pull requests welcome.

Open for pull requests in the following areas:

• Collision detection
  • throw a warning and don't compile when:
    • a block is created twice (name collisions)
    • a block makes reference to another block

Updating 3.0 for CommonJS users.

I added a babel plugin to correctly adapt the default export to the expected CommonJS type.

To upgrade change const atRuleBem = require('postcss-atrule-bem').default; to const atRuleBem = require('postcss-atrule-bem');