public function validURLSegment()
{
$isValid = parent::validURLSegment();
// Veto the validation rules if its false. In this case, some logic
// needs to be duplicated from parent to find out the exact reason the validation failed.
if (!$isValid) {
$IDFilter = $this->ID ? "AND \"SiteTree\".\"ID\" <> {$this->ID}" : null;
$parentFilter = null;
if (Config::inst()->get('SiteTree', 'nested_urls')) {
if ($this->ParentID) {
$parentFilter = " AND \"SiteTree\".\"ParentID\" = {$this->ParentID}";
} else {
$parentFilter = ' AND "SiteTree"."ParentID" = 0';
}
}
$origDisableSubsiteFilter = Subsite::$disable_subsite_filter;
Subsite::$disable_subsite_filter = true;
$existingPage = DataObject::get_one('SiteTree', "\"URLSegment\" = '{$this->URLSegment}' {$IDFilter} {$parentFilter}", false);
Subsite::$disable_subsite_filter = $origDisableSubsiteFilter;
$existingPageInSubsite = DataObject::get_one('SiteTree', "\"URLSegment\" = '{$this->URLSegment}' {$IDFilter} {$parentFilter}", false);
// If URL has been vetoed because of an existing page,
// be more specific and allow same URLSegments in different subsites
$isValid = !($existingPage && $existingPageInSubsite);
}
return $isValid;
}