Views exposed filter example. README.md file is not up to date.

Thank you, Peter, for reporting.
Indeed it is out of date.

Please, advise and help with that.
Do you suggest any changes?

Anyone can do a basic ( Create Issue fork for this ) and use the Web IDE from Gitlab.

Changes are welcomed and they will be committed :)

Hi, I think the problem is mainly, that a keyvalue is needed to be saved on the backend possibly for security reasons.

$key_value_storage = \Drupal::service('keyvalue')->get('entity_autocomplete');
if (!$key_value_storage->has($selection_settings_key)) {
  $key_value_storage->set($selection_settings_key, $selection_settings);
}

And a the url should be generated this way:

$url = Drupal\core\Url::fromRoute(
  'autocomplete_deluxe.autocomplete',
  $route_parameters,
  ['absolute' => TRUE]
  )->getInternalPath();

With these modifications it worked for me.

As of Drupal 11.1.7 and Autocomplete Deluxe 2.1.2, the previous code no longer works. Here is an updated version that is working for me. I can create a patch for the readme file if the maintainer is interested:

use Drupal\Component\Utility\Crypt;
use Drupal\Core\Site\Settings;

/**
 * Implements hook_form_alter().
 */
function your_module_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  if ($form_id == 'views_exposed_form') {
    // Add a call for each exposed filter you want to alter, using the field's machine name.
    your_module_autocomplete_deluxe_filter('field_tags', $form);
    your_module_autocomplete_deluxe_filter('field_categories', $form);
  }
}

/**
 * Converts the exposed filter of a field into an autocomplete deluxe widget.
 *
 * @param string $field_name
 *   Name of the field included as exposed filter in the form.
 * @param array $form
 *   Instance of the form array.
 */
function your_module_autocomplete_deluxe_filter(string $field_name, array &$form) {
  $filter_id = $form['#info']['filter-' . $field_name . '_target_id']['value'] ?? FALSE;

  if (!isset($form[$filter_id])) {
    return;
  }

  $selection_settings = [
    'target_bundles' => $form[$filter_id]['#selection_settings']['target_bundles'],
    'sort' => ['field' => '_none'],
    'auto_create' => FALSE,
    // Even though we've specified '0' for 'auto_create', it seems that
    // a value for 'auto_crteate_bundle' is required for this to work.
    'auto_create_bundle' => 'tags',
    'match_operator' => 'CONTAINS',
  ];

  $target_type = $form[$filter_id]['#target_type'];
  $selection_handler = 'default:taxonomy_term';
  $data = serialize($selection_settings) . $target_type . $selection_handler;

  $selection_settings_key = Crypt::hmacBase64($data, Settings::getHashSalt());

  $key_value_storage = \Drupal::service('keyvalue')->get('entity_autocomplete');
  if (!$key_value_storage->has($selection_settings_key)) {
    $key_value_storage->set($selection_settings_key, $selection_settings);
  }

  $route_parameters = [
    'target_type' => $target_type,
    'selection_handler' => $selection_handler,
    'selection_settings_key' => $selection_settings_key,
  ];

  $url = \Drupal::urlGenerator()->getPathFromRoute('autocomplete_deluxe.autocomplete', $route_parameters);

  $form[$filter_id] = [
    '#type' => 'autocomplete_deluxe',
    '#autocomplete_deluxe_path' => $url,
    '#selection_settings' => $selection_settings,
    '#multiple' => TRUE,
    '#target_type' => $target_type,
    '#selection_handler' => $selection_handler,
    '#limit' => 10,
    '#size' => 60,
    '#new_terms' => FALSE,
    '#min_length' => FALSE,
    '#delimiter' => ',',
    '#not_found_message_allow' => FALSE,
    '#not_found_message' => "The term '@term' will be added.",
    '#cardinality' => -1,
  ];
}

Thank you, David for tracing it to the key value store, Nishant for the first commit on the fork, and Proteo for the working code.

Built both examples in a scratch module on Drupal 11.4 and ran them.

A form of my own: the element renders, the suggestion list comes back from the controller, a tag is added and the form submits. It also showed the undefined array key warning for #cardinality, which is #3501341: Fix Warning: Undefined array key cardinality and has a merge request of its own.

A view with an exposed taxonomy filter: the element replaces the filter, suggestions come back, and applying the filter with Drupal (7) returns exactly the three nodes tagged with that term.

The merge request rewrites the FAQ with both examples, drops the dead auto_create_bundle line and its typo, and builds the route through the URL generator.

To review, test, then merge.