function hook_theme_suggestions_HOOK_alter

Alters named suggestions for a specific theme hook.

This hook allows any module or theme to provide alternative theme function or template name suggestions and reorder or remove suggestions provided by hook_theme_suggestions_HOOK() or by earlier invocations of this hook.

HOOK is the least-specific version of the hook being called. For example, if '#theme' => 'node__article' is called, then node_theme_suggestions_node() will be invoked, not node_theme_suggestions_node__article(). The specific hook called (in this case 'node__article') is available in $variables['theme_hook_original'].

Implementations of this hook must be placed in *.module or *.theme files, or must otherwise make sure that the hook implementation is available at any given time.

@todo Add @code sample.

Parameters

array $suggestions: An array of theme suggestions.

array $variables: An array of variables passed to the theme hook. Note that this hook is invoked before any preprocessing.

See also

hook_theme_suggestions_alter()

hook_theme_suggestions_HOOK()

Related topics

File

core/lib/Drupal/Core/Render/theme.api.php, line 719

Hooks and documentation related to the theme and render system.

Code

function hook_theme_suggestions_HOOK_alter(array &$suggestions, array $variables) {
  if (empty($variables['header'])) {
    $suggestions[] = 'hookname__no_header';
  }
}