public function AdvaggCssCollectionGrouper::group in Advanced CSS/JS Aggregation 8.4

Same name in this branch

1. 8.4 advagg_old_ie_compatibility/src/Asset/AdvaggCssCollectionGrouper.php \Drupal\advagg_old_ie_compatibility\Asset\AdvaggCssCollectionGrouper::group()
2. 8.4 advagg_bundler/src/Asset/AdvaggCssCollectionGrouper.php \Drupal\advagg_bundler\Asset\AdvaggCssCollectionGrouper::group()

Same name and namespace in other branches

1. 8.3 advagg_old_ie_compatibility/src/Asset/AdvaggCssCollectionGrouper.php \Drupal\advagg_old_ie_compatibility\Asset\AdvaggCssCollectionGrouper::group()

If enabled ensures that agreggates have a configurable maximum number of selectors. By default 4095 to work with the limits of older IE versions.

Overrides CssCollectionGrouper::group

File

advagg_old_ie_compatibility/src/Asset/AdvaggCssCollectionGrouper.php, line 37

Class

AdvaggCssCollectionGrouper

Groups CSS assets.

Namespace

Drupal\advagg_old_ie_compatibility\Asset

Code

public function group(array $css_assets) {
  if (!$this->config
    ->get('active')) {
    return parent::group($css_assets);
  }
  $limit = $this->config
    ->get('limit');
  $groups = [];

  // If a group can contain multiple items, we track the information that must
  // be the same for each item in the group, so that when we iterate the next
  // item, we can determine if it can be put into the current group, or if a
  // new group needs to be made for it.
  $current_group_keys = NULL;

  // When creating a new group, we pre-increment $i, so by initializing it to
  // -1, the first group will have index 0.
  $i = -1;
  $selectors = 0;
  foreach ($css_assets as $item) {

    // The browsers for which the CSS item needs to be loaded is part of the
    // information that determines when a new group is needed, but the order
    // of keys in the array doesn't matter, and we don't want a new group if
    // all that's different is that order.
    ksort($item['browsers']);

    // If the item can be grouped with other items, set $group_keys to an
    // array of information that must be the same for all items in its group.
    // If the item can't be grouped with other items, set $group_keys to
    // FALSE. We put items into a group that can be aggregated together:
    // whether they will be aggregated is up to the _drupal_css_aggregate()
    // function or an
    // override of that function specified in hook_css_alter(), but regardless
    // of the details of that function, a group represents items that can be
    // aggregated. Since a group may be rendered with a single HTML tag, all
    // items in the group must share the same information that would need to
    // be part of that HTML tag.
    switch ($item['type']) {
      case 'file':

        // Group file items if their 'preprocess' flag is TRUE.
        // Help ensure maximum reuse of aggregate files by only grouping
        // together items that share the same 'group' value.
        $group_keys = $item['preprocess'] ? [
          $item['type'],
          $item['group'],
          $item['media'],
          $item['browsers'],
        ] : FALSE;
        break;
      case 'external':

        // Do not group external items.
        $group_keys = FALSE;
        break;
    }

    // If the group keys don't match the most recent group we're working with,
    // then a new group must be made.
    if ($group_keys !== $current_group_keys) {
      $selectors = 0;
      $i++;

      // Initialize the new group with the same properties as the first item
      // being placed into it. The item's 'data', 'weight' and 'basename'
      // properties are unique to the item and should not be carried over to
      // the group.
      $groups[$i] = $item;
      unset($groups[$i]['data'], $groups[$i]['weight'], $groups[$i]['basename']);
      $groups[$i]['items'] = [];
      $current_group_keys = $group_keys ? $group_keys : NULL;
    }
    if (isset($item['selectors'])) {
      $selectors += $item['selectors'];
      if ($selectors > $limit) {
        $selectors = $item['selectors'];
        $i++;
        $groups[$i] = $item;
        unset($groups[$i]['data'], $groups[$i]['weight'], $groups[$i]['basename']);
        $groups[$i]['items'] = [];
      }
    }

    // Add the item to the current group.
    $groups[$i]['items'][] = $item;
  }
  return $groups;
}