Same name and namespace in other branches

1. 11.x core/lib/Drupal/Core/Asset/JsCollectionGrouper.php \Drupal\Core\Asset\JsCollectionGrouper::group()
2. 10 core/lib/Drupal/Core/Asset/JsCollectionGrouper.php \Drupal\Core\Asset\JsCollectionGrouper::group()
3. 9 core/lib/Drupal/Core/Asset/JsCollectionGrouper.php \Drupal\Core\Asset\JsCollectionGrouper::group()
4. 8.9.x core/lib/Drupal/Core/Asset/JsCollectionGrouper.php \Drupal\Core\Asset\JsCollectionGrouper::group()

Puts multiple items into the same group if they are groupable. Items of the 'file' type are groupable if their 'preprocess' flag is TRUE. Items of the 'external' type are not groupable.

Also ensures that the process of grouping items does not change their relative order. This requirement may result in multiple groups for the same type, if needed to accommodate other items in between.

Parameters

array $assets: An asset collection.

Return value

array A sorted array of asset groups.

Overrides AssetCollectionGrouperInterface::group

File

core/lib/Drupal/Core/Asset/JsCollectionGrouper.php, line 21

Class

JsCollectionGrouper

Groups JavaScript assets.

Namespace

Drupal\Core\Asset

Code

public function group(array $js_assets) {
  $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;
  // If a group encapsulates one or more libraries, e.g. all relevant files
  // from each library are contained in the group, instead of across groups
  // due to weight etc. it is possible to generate an aggregate based purely
  // on the libraries represented in the group rather than the full context of
  // the request. In order to do this, we need to keep track of whether
  // libraries span multiple groups or not.
  $first_seen_libraries = [];
  $record_libraries = TRUE;
  $index = -1;
  foreach ($js_assets as $item) {
    switch ($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'],
          $item['group'],
        ] : FALSE;
        if ($item['aggregate_target']['js'] === TRUE) {
          $group_keys[] = $item['library'];
        }
        elseif ($item['aggregate_target']['js']) {
          $group_keys[] = $item['aggregate_target']['js'];
        }
        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) {
      $record_libraries = TRUE;
      $index++;
      // Initialize the new group with the same properties as the first item
      // being placed into it. The item's 'data' and 'weight' properties are
      // unique to the item and should not be carried over to the group.
      $groups[$index] = $item;
      unset($groups[$index]['data'], $groups[$index]['weight'], $groups[$index]['library']);
      $groups[$index]['items'] = [];
      $current_group_keys = $group_keys ?: NULL;
    }
    $seen_index = $first_seen_libraries[$item['library']] ?? NULL;
    // The first time a library is seen, add it to the list of libraries for
    // the group and record the index.
    if ($seen_index === NULL) {
      $first_seen_libraries[$item['library']] = $index;
      if ($record_libraries) {
        $groups[$index]['libraries'][] = $item['library'];
      }
    }
    // If a library has been seen in a previous index, this means that index
    // does not contain all of the assets for that library, so unset the
    // libraries key from that group and this one.
    if ($seen_index !== NULL && $seen_index !== $index) {
      unset($groups[$seen_index]['libraries']);
      unset($groups[$index]['libraries']);
      $record_libraries = FALSE;
    }
    // Add the item to the current group.
    $groups[$index]['items'][] = $item;
  }
  // Ensure libraries only appear once for each group and in the same order
  // every time.
  foreach ($groups as $index => $group) {
    if (isset($group['libraries'])) {
      $groups[$index]['libraries'] = array_values(array_unique($group['libraries']));
    }
  }
  return $groups;
}

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