class EntityReference

class EntityReference extends Fields {
  
  /**
   * {@inheritdoc}
   */
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['separator'] = [
      'default' => '-',
    ];
    return $options;
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
    parent::buildOptionsForm($form, $form_state);
    // Expand the description of the 'Inline field' checkboxes.
    $form['inline']['#description'] .= '<br />' . $this->t("<strong>Note:</strong> In 'Entity Reference' displays, all fields will be displayed inline unless an explicit selection of inline fields is made here.");
  }
  
  /**
   * {@inheritdoc}
   */
  public function preRender($row) {
    // Force all fields to be inline by default.
    if (empty($this->options['inline'])) {
      $fields = $this->view
        ->getHandlers('field', $this->displayHandler->display['id']);
      $names = array_keys($fields);
      $this->options['inline'] = array_combine($names, $names);
    }
    return parent::preRender($row);
  }

}