How to create a dblog record from a views exposed form submission

I am trying to create a log record of searches made though my Search API View exposed form block in Drupal 9.

For some reason on a brand new search I get 2 duplicates (3 total entries), and it seems like I remember reading somewhere that the forms can be submitted multiple times. So I would like to know how I could eliminate that.

Update: here is an issue for Drupal 7 https://www.drupal.org/project/views/issues/2088549

Also, on searches for keywords that result in "no results" I am not seeing an entry in the log This behaviour seems hit and miss. I am using the following code with limited success:

/**
 * Implements hook_form_views_exposed_form_alter().
 */
function MY_form_views_exposed_form_alter(&$form, FormStateInterface &$form_state, $form_id) {
  // Create a search_log submission function for watchdog
  $view_names = array('search_api_view');
  $view = $form_state->getStorage('view');
  if ($form_id == 'views_exposed_form' && in_array($view['view']->id(), $view_names)) {
    if ($form['#id'] == 'views-exposed-form-search-api-view-page-1') {
      $form['#submit'][] = 'MY_search_api_log';
    }
  }
}

function MY_search_api_log(&$form, FormStateInterface $form_state) {
  if ($form_state->getValue('search_api_fulltext') != "") {
    // Create a link
    $link = Url::fromRoute('view.search_api_view.page_1', [], ['query' => ['search_api_fulltext' => $form_state->getValue('search_api_fulltext'), ], ]);
    // log the submission
    \Drupal::logger('search_api_results')->info($form_state->getValue('search_api_fulltext'), ['link' => Link::fromTextAndUrl('results', $link)->toString()]);
  }
}

I am trying to convert this function from a hook I am using in D7 which works fine:

/**
 * Implements hook_form_views_exposed_form_alter().
 */
function MY_form_views_exposed_form_alter(&$form, &$form_state, $form_id) {
  //Create a search_log submission function for watchdog
  if($form_state["view"]->base_field == 'search_api_id') {
    $form['#submit'][] = 'MY_search_api_log';
  }
}

function MY_search_api_log(&$form, $form_state) {
  if ($form_state['values']['search_api_views_fulltext'] != "") {
    $link = l('results', '/search-results', ['query' => ['search_api_views_fulltext' => $form_state['values']['search_api_views_fulltext'], ], ]);
    watchdog('search_api_results', $form_state['values']['search_api_views_fulltext'], [], WATCHDOG_INFO, $link);
  }
}

Two thoughts:

1. Instead of doing this on form submit handler, maybe just try doing the logger right in the alter hook or a preprocess hook before the page is rendered.

2. Then, to avoid the duplicate call, if the preprocess or alter hook is still getting executed multiple times, you need a way to ensure your log message is only called logged once.

   For this, there might be two approaches.

   • Use drupal_static to set a boolean.

   • Attach a key/value to the $form object after you print the watchdog message, and then prevent duplicate logging if the $form already has the key.