1 theme.api.php hook_form_system_theme_settings_alter(&$form, &$form_state)

Allow themes to alter the theme-specific settings form.

With this hook, themes can alter the theme-specific settings form in any way allowable by Backdrop's Form API, such as adding form elements, changing default values and removing form elements. See the Form API documentation on api.drupal.org for detailed information.

Note that the base theme's form alterations will be run before any sub-theme alterations.


$form: Nested array of form elements that comprise the form.

$form_state: A keyed array containing the current state of the form.


core/modules/system/theme.api.php, line 86


function hook_form_system_theme_settings_alter(&$form, &$form_state) {
  // Add a checkbox to toggle the breadcrumb trail.
  $form['toggle_breadcrumb'] = array(
    '#type' => 'checkbox',
    '#title' => t('Display the breadcrumb'),
    '#default_value' => theme_get_setting('toggle_breadcrumb'),
    '#description' => t('Show a trail of links from the homepage to the current page.'),