public function submitForm(array &$form, FormStateInterface $form_state) {
$selected = $form_state->getValue('tableselect');
foreach ($selected as $key => $value) {
- drupal_set_message(t('Submitted: @key = @value', ['@key' => $key, '@value' => $value]));
+ $this->messenger()->addStatus($this->t('Submitted: @key = @value', ['@key' => $key, '@value' => $value]));
}
}