/**
* Get the remote XML file contents and return its data (Version
* and Changelog). Uses the cached version if available and inside the time
* interval defined
*/
function wpgrade_update_notifier_latest_theme_version($interval)
{
$notifier_file_url = wpgrade::updade_notifier_xml();
$db_cache_field = 'notifier-cache-' . wpgrade::shortname();
$db_cache_field_last_updated = 'notifier-cache-last-updated-' . wpgrade::shortname();
$last = get_option($db_cache_field_last_updated);
$now = time();
// check the cache
if (!$last || $now - $last > $interval) {
// cache doesn't exist, or is old, so refresh it
$res = wp_remote_get($notifier_file_url);
$cache = wp_remote_retrieve_body($res);
if ($cache) {
// we got good results
update_option($db_cache_field, $cache);
update_option($db_cache_field_last_updated, time());
}
// read from the cache file
$notifier_data = get_option($db_cache_field);
} else {
// cache file is fresh enough, so read from it
$notifier_data = get_option($db_cache_field);
}
// Let's see if the $xml data was returned as we expected it to.
// If it didn't, use the default 1.0 as the latest version so that we don't have problems when the remote server hosting the XML file is down
if (strpos((string) $notifier_data, '<notifier>') === false) {
$notifier_data = '<?xml version="1.0" encoding="UTF-8"?><notifier><latest>1.0</latest><changelog></changelog></notifier>';
}
// Load the remote XML data into a variable and return it
$xml = simplexml_load_string($notifier_data);
return $xml;
}
