SiteSettingsForm::submitForm

public SiteSettingsForm::submitForm(array &$form, FormStateInterface $form_state)

public function submitForm(array &$form, FormStateInterface $form_state) {
  global $install_state;

  // Update global settings array and save.
  $settings = array();
  $database = $form_state->get('database');
  $settings['databases']['default']['default'] = (object) array(
    'value' => $database,
    'required' => TRUE,
  );
  $settings['settings']['hash_salt'] = (object) array(
    'value' => Crypt::randomBytesBase64(55),
    'required' => TRUE,
  );
  // Remember the profile which was used.
  $settings['settings']['install_profile'] = (object) array(
    'value' => $install_state['parameters']['profile'],
    'required' => TRUE,
  );

  drupal_rewrite_settings($settings);

  // Add the config directories to settings.php.
  drupal_install_config_directories();

  // Indicate that the settings file has been verified, and check the database
  // for the last completed task, now that we have a valid connection. This
  // last step is important since we want to trigger an error if the new
  // database already has Drupal installed.
  $install_state['settings_verified'] = TRUE;
  $install_state['config_verified'] = TRUE;
  $install_state['database_verified'] = TRUE;
  $install_state['completed_task'] = install_verify_completed_task();
}