Get extra information to the POST data as ajax.js does.
string Additional post data.
protected function getAjaxPageStatePostData() {
$extra_post = '';
$drupal_settings = $this->drupalSettings;
if (isset($drupal_settings['ajaxPageState'])) {
$extra_post .= '&' . urlencode('ajax_page_state[theme]') . '=' . urlencode($drupal_settings['ajaxPageState']['theme']);
$extra_post .= '&' . urlencode('ajax_page_state[theme_token]') . '=' . urlencode($drupal_settings['ajaxPageState']['theme_token']);
foreach ($drupal_settings['ajaxPageState']['css'] as $key => $value) {
$extra_post .= '&' . urlencode("ajax_page_state[css][{$key}]") . '=1';
}
foreach ($drupal_settings['ajaxPageState']['js'] as $key => $value) {
$extra_post .= '&' . urlencode("ajax_page_state[js][{$key}]") . '=1';
}
}
return $extra_post;
}