BEM.php

BEM.php

<?php
/**
 * BEM
 * experimental function to output BEM style class names from strings and/or arrays
 * @param string|array $b block
 * @param string|array $e element
 * @param string|array $m modifier
 * @return string class names
 *
 * eg:
 * BEM('page', 'title')                       > page_title
 * BEM('btn', 0, 'primary')                   > btn btn--primary
 * BEM(array('node', 'page-node'), 'title')   > node_title page-node_title
 * BEM(array('node', 'page-node'), 0, array('teaser', 'nested')) > node page-node node--teaser page-node--teaser node--nested page-node--nested ... fiou
 */
function BEM($b = array(), $e = array(), $m = array()) {
  $element_separator = '_';
  $modifier_separator = '--';

  $classes = array();
  $modifiers = array();

  // Every arguments could be a string or an array
  if(is_string($b)) $b = array($b);
  if(is_string($e)) $e = array($e);
  if(is_string($m)) $m = array($m);;

  foreach($b as $block) {
    // Block only
    if(empty($e)) {
      $classes[] = $block;

    // Element only
    } else {
      foreach($e as $element) {
        $classes[] = $block.$element_separator.$element;
      }
    }
  }

  // append modifiers after classes
  foreach($m as $modifier) {
    foreach($classes as $classname) {
      $modifiers[] = $classname.$modifier_separator.$modifier;
    }
  }

  return implode(' ', array_merge($classes, $modifiers));
}