/**
* Adds the sitemap change frequency field
*/
private function AddSitemapChangeFrequencyField()
{
$name = 'SitemapChangeFrequency';
$value = $this->page->Exists() ? $this->page->GetSitemapChangeFrequency() : (string) ChangeFrequency::Weekly();
$field = new Select($name, $value);
$values = ChangeFrequency::AllowedValues();
foreach ($values as $val) {
$field->AddOption($val, Trans('Core.Sitemap.ChangeFrequency.' . ucfirst($val)));
}
$this->AddField($field);
}
