_ppm_utilities_order_css.php

<?php
/**
 * Promote the theme stylesheets.
 *
 * Implements hook_css_alter().
 *
 * @param array &$css
 *   An array of all CSS items (files and inline CSS) being requested on the page.
 * @param array $options
 *   (optional) An associative array containing:
 *     - replace: (optional) an associative array of media type from => to.
 *     - reset: (optional) an array list of reset files to be moved at the
 *       beginning of output stack. Default to `array('reset')`.
 *     - unset_dir: (optional) A directory name used in the `.info` file to
 *       remove CSS inserted by the core and modules. Default to `'kill'`.
 *   Example usage:
 *   @code
 *     _ppm_utilities_order_css($css, array(
 *       'replace' => array('all' => 'screen, projection'),
 *       'reset'   => array('reset', 'reset-custom')
 *     ));
 *   @endcode
 *
 *  @link http://pioupioum.fr/
 */
function _ppm_utilities_order_css(&$css, $options = array()) {
  $theme    = array();
  $stack    = array();
  $defaults = array(
    'replace'   => array(),
    'reset'     => array('reset'),
    'unset_dir' => 'kill',
  );
  $options += $defaults;
  
  // Checks all reset CSS files and adds right to left should be included
  // by the module Locale in {@link locale_css_alter()}.
  if (count($options['reset'])) {
    $reset_css = $options['reset'];
    array_walk($reset_css, function ($name) use (&$options) {
      if (FALSE !== strpos($name, '-rtl')) {
        $options['reset'][] = $name . '-rtl';
      }
    });
    unset($reset_css);
  }
  
  /**
   * Cleanup media type.
   *
   * @param string $media
   *   The input media type to clean.
   *
   * @return string
   */
  $sanitize_media = function ($media) {
    if (FALSE !== strpos($media, ',')) {
      $media = explode(',', $media);
      array_walk($media, function (&$v) { $v = strtolower(trim($v)); });
      natsort($media);
      $media = implode(',', $media);
    }
  
    return $media;
  };
  
  // Why consume CPU cycles to process stylesheets that we do not want?
  // Let's remove them from the stack maintained by Drupal.
  $killed = array();
  $css = array_filter($css, function ($stylesheet) use (&$killed, $options) {
    if (FALSE !== strpos($stylesheet['data'], '/' . $options['unset_dir'] . '/')) {
      $killed[] = basename($stylesheet['data']);
      return FALSE;
    }
    return TRUE;
  });
  $css = array_filter($css, function ($stylesheet) use ($killed) {
    return !in_array(basename($stylesheet['data']), $killed);
  });
  unset($killed, $stylesheet);

  // Flattening substitutions of media types.
  if (count($options['replace'])) {
    $from = array_map($sanitize_media, array_keys($options['replace']));
    $to   = array_map($sanitize_media, array_values($options['replace']));
    $options['replace'] = array_combine($from, $to);
    unset($from, $to);
  }

  foreach ($css as $delta => $stylesheet) {
    // Never deal with external resources.
    if ('external' === $stylesheet['type']) {
      $stack[$delta] = $stylesheet;
      continue;
    }

    // We force the loading of CSS on every page to limit the number
    // of aggregate files.
    if (!$stylesheet['every_page']) {
      $stylesheet['every_page'] = TRUE;
    }

    // Standardize media types and make substitutions if necessary.
    $media = $sanitize_media($stylesheet['media']);
    if (isset($options['replace'][$media])) {
      $media = $options['replace'][$media];
    }
    $stylesheet['media'] = $media;

    // The stylesheet has been declared by the theme, we store the key
    // to increase their weight at the end of the process.
    if (CSS_THEME === $stylesheet['group']) {
      $theme[$delta] = $stylesheet;
    }
    // Otherwise, it is a stylesheet added by the core or a module, we move it
    // in the theme group to group 'theme' into a single file after aggregation.
    else {
      $stylesheet['group'] = CSS_THEME;
      $stack[$delta]       = $stylesheet;
    }
  }

  // We force the loading of CSS declared by the theme to the end of the stack.
  $i = 0;
  if (!empty($stack)) {
    foreach (array_keys($stack) as $delta) {
      $stack[$delta]['weight'] = (++$i) / 1000;
    }
    $i = $stack[$delta]['weight'];
  }

  foreach (array_keys($theme) as $delta) {
    // If it exists, we ensure that the reset stylesheets is loaded first.
    if (in_array(basename($delta, '.css'), $options['reset'])) {
      $theme[$delta]['weight'] = -2 + $theme[$delta]['weight'];
    }
    else {
      $i += 0.001;
      $theme[$delta]['weight'] = $i;
    }
  }

  $css = array_merge($stack, $theme);
}