Get a random alphanumeric string.
/**
* @param $prefix
* @param $suffix
* @param $size
*
* @return string
*/
private function randomKey($prefix, $suffix, $size)
{
$key = "";
$chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
for ($i = 0; $i < $size; $i++)
{
$key .= $chars[rand(0, strlen($chars) - 1)];
}
return $prefix . $key . $suffix;
}