function hook_preprocess

Same name and namespace in other branches
  1. 7.x modules/system/theme.api.php \hook_preprocess()
  2. 9 core/lib/Drupal/Core/Render/theme.api.php \hook_preprocess()
  3. 10 core/lib/Drupal/Core/Render/theme.api.php \hook_preprocess()
  4. 11.x core/lib/Drupal/Core/Render/theme.api.php \hook_preprocess()

Preprocess theme variables for templates.

This hook allows modules to preprocess theme variables for theme templates. It is called for all theme hooks implemented as templates, but not for theme hooks implemented as functions. hook_preprocess_HOOK() can be used to preprocess variables for a specific theme hook, whether implemented as a template or function.

For more detailed information, see the Theme system overview topic.


$variables: The variables array (modify in place).

$hook: The name of the theme hook.

Related topics

5 functions implement hook_preprocess()

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

common_test_preprocess in core/modules/system/tests/modules/common_test/common_test.module
Implements MODULE_preprocess().
contextual_preprocess in core/modules/contextual/contextual.module
Implements hook_preprocess().
search_invoke_preprocess in core/modules/search/search.module
Invokes hook_search_preprocess() to simplify text.
search_langcode_test_search_preprocess in core/modules/search/tests/modules/search_langcode_test/search_langcode_test.module
Implements hook_search_preprocess().
template_preprocess in core/includes/
Adds a default set of helper variables for preprocessors and templates.


core/lib/Drupal/Core/Render/theme.api.php, line 554


function hook_preprocess(&$variables, $hook) {
    static $hooks;
    // Add contextual links to the variables, if the user has permission.
    if (!\Drupal::currentUser()->hasPermission('access contextual links')) {
    if (!isset($hooks)) {
        $hooks = theme_get_registry();
    // Determine the primary theme function argument.
    if (isset($hooks[$hook]['variables'])) {
        $keys = array_keys($hooks[$hook]['variables']);
        $key = $keys[0];
    else {
        $key = $hooks[$hook]['render element'];
    if (isset($variables[$key])) {
        $element = $variables[$key];
    if (isset($element) && is_array($element) && !empty($element['#contextual_links'])) {
        $variables['title_suffix']['contextual_links'] = contextual_links_view($element);
        if (!empty($variables['title_suffix']['contextual_links'])) {
            $variables['attributes']['class'][] = 'contextual-links-region';

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