BemPug

Simple mixins to help you writing code on BEM methodology in pug or jade projects.

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Anchors

Install | Mixins | Examples | Helpers | Changelog

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Install

Install from npm:

npm i bempug -D

Then include index file to your pug or jade project:

include ../../node_modules/bempug/index

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Mixins

Block mixin:

+b( name, data, tag )

• name String
• data String or Object
  • data.m String — block modifier
  • data.p Boolean — disable parent mode
  • data.e Array or String — mix block with element
  • data.b Array or String — mix block with another block
  • data.t String — block tag
  • data.s String — block separators
• tag String

If data argument is String it will be a modifier.

Element mixin:

+e( name, data, tag )

• name String
• data String or Object
  • data.m String — element modifier
  • data.p String — parent block
  • data.e Array or String — mix element with another element
  • data.b Array or String — mix element with block
  • data.t String — element tag
  • data.s String — element separators
• tag String

If data argument is String it will be a modifier.

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Examples

Block | Element | Modifier | Tag | Mix | Separators

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Block

Simple example:

+b( 'block' )
    +e( 'element' ) Text

<div class="block">
    <div class="block__element">Text</div>
</div>

You can to disable parent mode and element will ignore this block:

+b( 'header' )
    +b( 'grid', {p: false} ) // or short {p:0}
        +e( 'logo' ) Logo

<div class="header">
    <div class="grid">
        <div class="header__logo">Logo</div>
    </div>
</div>

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Element

Element depends on parent block:

+b( 'content' )
    +e( 'layout' ) Content

<div class="content">
    <div class="content__layout">Content</div>
</div>

You can set parent block for element directly:

+b( 'content' )
    +e( 'layout', {p: 'page'} ) Content

<div class="content">
    <div class="page__layout">Content</div>
</div>

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Modifier

Block and element have modifier:

+b( 'alert', 'success' )
    +e( 'text', 'bolder' ) Success

<div class="alert alert--success">
    <div class="alert__text alert__text--bolder">Success</div>
</div>

Block and element have more than one modifier:

+b( 'alert', 'success.active' )
    +e( 'text', 'bolder.italic' ) Success

<div class="alert alert--success alert--active">
    <div class="alert__text alert__text--bolder alert__text--italic">Success</div>
</div>

Also, you can set modifiers in Object:

+b( 'alert', {m: 'success.active'} ) Success

<div class="alert alert--success alert--active">Success</div>

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Tag

Default tag is div, but you can set it directly:

+b( 'news', {}, 'article' )
    +e( 'title', {}, 'h1' ) Title
 
// Or in data Object
 
+b( 'news', {t: 'article'} )
    +e( 'title', {t: 'h1'} ) Title

<article class="news">
    <h1 class="news__title">Title</h1>
</article>

Sometimes mixin can be smart and tag depends on parent or attributes:

+b( 'list', {t: 'ul'} )
    +e( 'item' ) My item 1
    +e( 'item' ) My item 2
    +e( 'item' ) My item 3
 
+b( 'link' )(href='https://www.npmjs.com/package/bempug')
    +b( 'text' ) My text

<ul class="list">
    <li class="list__item">My item 1</li>
    <li class="list__item">My item 2</li>
    <li class="list__item">My item 3</li>
</ul>
 
<a class="link" href="https://www.npmjs.com/package/bempug">
    <span class="text">My text</span>
</a>

Also, you can use tagByName global option for set default tag by name:

- BEMPUG.tagByName = {list: 'ul', form: 'form', fields: 'fieldset'};
 
+b( 'list' )
    +e( 'item' ) Item
    +e( 'item' ) Item
    
+b( 'form' )
    +e( 'fields' ) Fields

<ul class="list">
    <li class="list__item">Item</li>
    <li class="list__item">Item</li>
</ul>
 
<form class="form">
    <fieldset class="form__fields">Fields</fieldset>
</form>

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Mix

Block is mixed with element:

+b( 'title', {e: 'article'} ) Title

<div class="title article__title">Title</div>

You can set name of element in mix with colon:

+b( 'title', {e: 'article:my-name'} ) Title

<div class="title article__my-name">Title</div>

Block is mixed with two elements:

+b( 'title', {e: ['article', 'content']} ) Title

<div class="title article__title content__title">Title</div>

Also, you can use ampersand & sign as parent block reference:

+b( 'news' )
    +b( 'title', {e: '&'} ) Title
    +b( 'text', {e: '&:description'} ) Text

<div class="news">
    <div class="title news__title">Title</div>
    <div class="text news__description">Text</div>
</div>

Block is mixed with element which has modifiers:

+b( 'title', {e: 'news|bolder.size-m'} ) Title

<div class="title news__title news__title--bolder news__title--size-m">Title</div>

Element is mixed with another element:

+b( 'footer' )
    +e( 'bottom', {e: 'page'} )

<div class="footer">
    <div class="footer__bottom page__bottom"></div>
</div>

Element is mixed with block:

+b( 'footer' )
    +e( 'bottom', {b: 'grid'} )

<div class="footer">
    <div class="footer__bottom grid"></div>
</div>

Block is mixed with another block:

+b( 'article', {b: 'news'} ) Content

<div class="article news">Content</div>

Block is mixed with another block which has modifiers:

+b( 'article', {b: 'news|first'} ) Content

<div class="article news news--first">Content</div>

Block is mixed with two blocks which have modifiers:

+b( 'article', {b: ['news|first','fixed|active']} ) Content

<div class="article news news--first fixed fixed--active">Content</div>

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Separators

You can change global separators:

- BEMPUG.modifier = '_';
- BEMPUG.element = '__';
 
+b( 'alert', 'success.active' )
    +e( 'text', 'bolder.italic' ) Success

<div class="alert alert_success alert_active">
    <div class="alert__text alert__text_bolder alert__text_italic">Success</div>
</div>

Also, you can set separators for each block and ignore global settings 'modifier|element':

+b( 'news', {e: 'content', m: 'first', s: '---|___' } )
    +b( 'text', {e: true, m: 'bolder'} ) Text

<div class="news news---first content___news">
    <div class="text text---bolder news___text">Text</div>
</div>

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Helpers

Get current block | Get current parent | Callbacks

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Get current block

You can get current block name:

+b( 'nav' )
    +e( 'item' )
        - console.log( BEMPUG.getCurrentBlock() ); // 'nav'
        +b( 'img' )
            - console.log( BEMPUG.getCurrentBlock() ); // 'img'

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Get current parent

You can get current parent Object:

+b( 'html', 'no-js', 'html' )(lang='en')
    - console.log( BEMPUG.getCurrentParent() );

{ type: 'block',
  name: 'html',
  tag: 'html',
  attributes: { lang: 'en' },
  sep: { modifier: '--', element: '__' },
  classes: [ 'html', 'html--no-js' ],
  parent: {},
  selfClosing: false }

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Callbacks

You can set beforeParse callback:

- BEMPUG.beforeParse[ 'input' ] = function( block ) {
 
    if ( typeof block.data.m === 'undefined' ) block.data.m = 'default';
}
 
+b( 'input', {m: 'search'} ) // Have modifier 'search'
 
+b( 'input' ) // No modifier, but we set modifier 'default' by callback

<input class="input input--search">
<input class="input input--default">

You can set afterParse callback:

- BEMPUG.afterParse[ 'page' ] = function( block ) {
 
    block.setTag( 'body' );
    block.addModifier( 'test' );
    block.attributes.itemscope = true;
    block.attributes.itemtype = 'http://schema.org/WebPage';
}
 
+b( 'page' ) My page

<body class="page page--test" itemscope itemtype="http://schema.org/WebPage">My page</body>

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Changelog

1.1.1

• Fixed: disable parent mode not work in cb
• Fixed: name of element in mix with another element

1.1.0

• Add: ampersand sign for mix
• Add: mix element with blocks and another elements

1.0.2

• Add: some global helpers
• Add: before / after parse callback
• Fixed: block and element separators work for any descendant
• Fixed: default tag depends on parent tag for any descendant

1.0.1

• Add: disable parent mode for blocks

1.0.0

• Release version

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Thanks

Many thanks to Roman Komarov for the original idea.