function hook_preprocess_HOOK

Preprocess theme variables for a specific theme hook.

This hook allows modules to preprocess theme variables for a specific theme hook. It should only be used if a module needs to override or add to the theme preprocessing for a theme hook it didn't define.

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

Parameters

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

Related topics

Hooks
Define functions that alter the behavior of Drupal core.
266 functions implement hook_preprocess_HOOK()

Note: the procedural functions in this list are found by pattern matching, so the list may include some functions that are not actually implementations of this hook.

aggregator_preprocess_block in core/modules/aggregator/aggregator.module
Implements hook_preprocess_HOOK() for block templates.
bartik_preprocess_block in core/themes/bartik/bartik.theme
Implements hook_preprocess_HOOK() for block.html.twig.
bartik_preprocess_html in core/themes/bartik/bartik.theme
Implements hook_preprocess_HOOK() for HTML document templates.
bartik_preprocess_maintenance_page in core/themes/bartik/bartik.theme
Implements hook_preprocess_HOOK() for maintenance-page.html.twig.
bartik_preprocess_menu in core/themes/bartik/bartik.theme
Implements hook_preprocess_HOOK() for menu.html.twig.

... See full list

File

core/lib/Drupal/Core/Render/theme.api.php, line 601

Code

function hook_preprocess_HOOK(&$variables) {
  // This example is from rdf_preprocess_image(). It adds an RDF attribute
  // to the image hook's variables.
  $variables['attributes']['typeof'] = [
    'foaf:Image',
  ];
}

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