I am implementing dependent filters in views exposed filter for content:datasource search(Solr search). I have a requirement that in exposed dropdown field when a category is selected, by ajax i need to fetch the sub-categories and show up in another dropdown.For this I tried like below but its not going to callback function only. There is nothing logging in the network console also. Can anyone help me here to resolve.
use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Ajax\HtmlCommand;
function module_form_alter(&$form, &$form_state, $form_id) {
$form['field_categories']['#ajax'] = array(
'callback' => 'module_get_subcategories',
// 'callback' => '::module_get_subcategories',
'event' => 'change',
'wrapper' => 'edit-field-subcategory',
'progress' => array(
'type' => 'throbber',
'message' => NULL,
),
);
}
function module_get_subcategories(&$form, FormStateInterface $form_state) {
$response = new AjaxResponse();
$message = 'test';
$response->addCommand(new HtmlCommand('#edit-field-subcategory', $message));
return $response;
}