function 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.

Parameters

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

$hook: The name of the theme hook.

Related topics

File

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

Code

function hook_preprocess(&$variables, $hook) {
    static $hooks;
    // Add contextual links to the variables, if the user has permission.
    if (!\Drupal::currentUser()->hasPermission('access contextual links')) {
        return;
    }
    if (!isset($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';
        }
    }
}