public function refreshCurrency($data, $isoCodeSource, $defaultCurrency)
    {
        if ($this->iso_code != $isoCodeSource)
        {
            /* Seeking for rate in feed */
            foreach ($data->item AS $obj)
                if ($this->iso_code == strval($obj->char3))
                    $this->conversion_rate = round($defaultCurrency->conversion_rate / floatval($obj->rate/$obj->size) , 6);
        }
        else
        {
            /* If currency is like isoCodeSource, setting it to default conversion rate */
                        $this->conversion_rate = round($defaultCurrency->conversion_rate / 1   , 6);
        }
        $this->update();
    }

    static public function refreshCurrenciesGetDefault($data, $isoCodeSource, $idCurrency)
    {
        $defaultCurrency = new Currency($idCurrency);

        /* Change defaultCurrency rate if not as currency of feed source */
        if ($defaultCurrency->iso_code != $isoCodeSource)
            foreach ($data->item AS $obj){
                
                if ($defaultCurrency->iso_code == strval($obj->char3))
                    $defaultCurrency->conversion_rate = round(floatval($obj->rate/$obj->size), 6);
                        }
        return $defaultCurrency;
    }

    static public function refreshCurrencies()
    {
        if (!$feed = @simplexml_load_file('http://bank-ua.com/export/currrate.xml'))
            return Tools::displayError('Cannot parse feed!');
        if (!$defaultCurrency = intval(Configuration::get('PS_CURRENCY_DEFAULT')))
            return Tools::displayError('No default currency!');
              
        $isoCodeSource = strval('UAH');
        $currencies = self::getCurrencies(true);
        $defaultCurrency = self::refreshCurrenciesGetDefault($feed, $isoCodeSource, $defaultCurrency);
                foreach ($currencies as $currency)
            if ($currency->iso_code != $defaultCurrency->iso_code)
                $currency->refreshCurrency($feed, $isoCodeSource, $defaultCurrency);
    }