private function _getFileLastModifiedTimesIndentifier($_file_paths = array())
{
// Creates a unique string identifier representing the modified times of files
// passed to it as a parameter.
$_file_paths = !is_array($_file_paths) ? array($_file_paths) : $_file_paths;
$iden = '';
foreach ($_file_paths as $file) {
if (App\Files::exists($file)) {
$time = App\Files::lastModified($file);
if ($time === false) {
xplog('Unable to get the last modified time of file "' . $file . '"', __METHOD__);
continue;
}
$iden .= $time;
} else {
xplog('Found that file "' . $file . '" does not exist when trying to get its last modified time.', __METHOD__);
}
}
return md5($iden);
}
