/**
* create or update a server entry
*
* This function is called when a remote server pings us, to mean its content has changed.
*
* If the provided URL does not exist, a new server profile is created.
* Else the profile is updated only if ping is still allowed for this server profile.
*
* @see services/ping.php
*
* @param string the title of the updated server
* @param string the link to it
* @return string either a null string, or some text describing an error to be inserted into the html response
*/
public static function ping($title, $url)
{
global $context;
// the entry already exists
if ($item = Servers::get_by_url($url)) {
// ensure this operation is allowed
if (isset($item['process_ping']) && $item['process_ping'] != 'Y') {
return 'You are not allowed to perform this operation.';
}
// clear the cache for this server
Cache::clear('server:' . $item['id']);
// update the existing record
$query = "UPDATE " . SQL::table_name('servers') . " SET " . "title='" . SQL::escape($title) . "', " . "edit_name='ping', " . "edit_id=0, " . "edit_address='', " . "edit_date='" . gmstrftime('%Y-%m-%d %H:%M:%S') . "'" . " WHERE id = " . SQL::escape($item['id']);
if (SQL::query($query) === FALSE) {
return 'ERROR';
}
// the entry does not exist yet
} else {
// create a new record
$query = "INSERT INTO " . SQL::table_name('servers') . " SET " . "title='" . SQL::escape($title) . "', " . "main_url='" . SQL::escape($url) . "', " . "edit_name='" . SQL::escape($title) . "', " . "edit_id=0, " . "edit_address='', " . "edit_date='" . gmstrftime('%Y-%m-%d %H:%M:%S') . "'";
if (SQL::query($query) === FALSE) {
return 'ERROR';
}
}
// clear the cache for server profiles
Cache::clear('servers');
// end of job
return NULL;
}
