OpenCart 🇺🇦

$this->db = $registry->get('db');
$this->config = $registry->get('config');

$weight_class_query = $this->db->query("SELECT * FROM " . DB_PREFIX . "weight_class wc LEFT JOIN " . DB_PREFIX . "weight_class_description wcd ON (wc.weight_class_id = wcd.weight_class_id) WHERE wcd.language_id = '" . (int)$this->config->get('config_language_id') . "'");

foreach ($weight_class_query->rows as $result) {
	$this->weights[$result['weight_class_id']] = array(
		'weight_class_id' => $result['weight_class_id'],
		'title'           => $result['title'],
		'unit'            => $result['unit'],
		'value'           => $result['value']
	);
}

if ($from == $to) {
	return $value;
}

if (isset($this->weights[$from])) {
	$from = $this->weights[$from]['value'];
} else {
	$from = 0;
}

if (isset($this->weights[$to])) {
	$to = $this->weights[$to]['value'];
} else {
	$to = 0;
}	

return $value * ($to / $from);

if (isset($this->weights[$weight_class_id])) {
	return number_format($value, 2, $decimal_point, $thousand_point) . $this->weights[$weight_class_id]['unit'];
} else {
	return number_format($value, 2, $decimal_point, $thousand_point);
}

if (isset($this->weights[$weight_class_id])) {
	return $this->weights[$weight_class_id]['unit'];
} else {
	return '';
}