Same name and namespace in other branches
  1. 7.x modules/system/system.api.php \hook_css_alter()
  2. 8.9.x core/lib/Drupal/Core/Render/theme.api.php \hook_css_alter()
  3. 9 core/lib/Drupal/Core/Render/theme.api.php \hook_css_alter()

Alter CSS files before they are output on the page.

Parameters

$css: An array of all CSS items (files and inline CSS) being requested on the page.

\Drupal\Core\Asset\AttachedAssetsInterface $assets: The assets attached to the current response.

\Drupal\Core\Language\LanguageInterface $language: The language of the request that the assets will be rendered for.

See also

Drupal\Core\Asset\LibraryResolverInterface::getCssAssets()

Related topics

Hooks
Define functions that alter the behavior of Drupal core.
1 function implements hook_css_alter()

Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.

settings_tray_css_alter in core/modules/settings_tray/settings_tray.module
Implements hook_css_alter().
1 invocation of hook_css_alter()
AssetResolver::getCssAssets in core/lib/Drupal/Core/Asset/AssetResolver.php

File

core/lib/Drupal/Core/Render/theme.api.php, line 1071
Hooks and documentation related to the theme and render system.

Code

function hook_css_alter(&$css, \Drupal\Core\Asset\AttachedAssetsInterface $assets, \Drupal\Core\Language\LanguageInterface $language) {

  // Remove defaults.css file.
  $file_path = \Drupal::service('extension.list.module')
    ->getPath('system') . '/defaults.css';
  unset($css[$file_path]);
}