我们在使用magento做日文站的时候就会出现一个问题 paypal快捷支付的货币始终都是美元，不论基础货币设置为日元或者美元，当选择paypal快捷支付的时候最终都会使用美元支付，我们今天的教程就是要修复这个当前货币的支付问题

这个功能的修改涉及到5个核心文件，我是直接修改的核心文件的 如果你个人喜欢又有这方面的需求 可以扩展成插件

先来说下需要修改的几个文件路径

app/code/core/Mage/Paypal/Model/Express.php

app/code/core/Mage/Paypal/Model/Cart.php

app/code/core/Mage/Paypal/Model/Express/Checkout.php

app/code/core/Mage/Sales/Model/Order/Payment.php

app/code/core/Mage/Core/Model/Store.php

主要要修改什么 先在这里说明一下，大家都知道paypal是可以支付多种货币的，关于这点可以下载官网的示例来看，想要改变支付的货币种类 要修改的一个是传给paypal的参数也就是货币符号,另外一个就是价格，虽然magento前台页面以及购物车看到的是日元，关键在于再给paypal传产品价格的时候用的是基础货币,而不是当前货币换算出来的结果，下面我就来发出关键代码，为有需要的同学提供方便

app/code/core/Mage/Paypal/Model/Express.php 

    /**
     * Order payment
     *
     * @param Mage_Sales_Model_Order_Payment $payment
     * @param float $amount
     * @return Mage_Paypal_Model_Express
     */
    public function order(Varien_Object $payment, $amount)
    {
	...
        //修改 :去掉getBaseCurrentCurrency() 中的Base
        $formatedPrice = $order->getCurrentCurrency()->formatTxt($amount);
	...

    /**
     * Capture payment
     *
     * @param Mage_Sales_Model_Order_Payment $payment
     * @param float $amount
     * @return Mage_Paypal_Model_Express
     */
    public function capture(Varien_Object $payment, $amount)
    {
	...
                $formatedPrice = $order->getCurrentCurrency()->formatTxt($amount);//修改

	...

    /**
     * Place an order with authorization or capture action
     *
     * @param Mage_Sales_Model_Order_Payment $payment
     * @param float $amount
     * @return Mage_Paypal_Model_Express
     */
    protected function _placeOrder(Mage_Sales_Model_Order_Payment $payment, $amount)
    {
        $order = $payment->getOrder();

        // prepare api call
        $token = $payment->getAdditionalInformation(Mage_Paypal_Model_Express_Checkout::PAYMENT_INFO_TRANSPORT_TOKEN);
        $api = $this->_pro->getApi()
            ->setToken($token)
            ->setPayerId($payment->
                getAdditionalInformation(Mage_Paypal_Model_Express_Checkout::PAYMENT_INFO_TRANSPORT_PAYER_ID))
            ->setAmount($amount)
            ->setPaymentAction($this->_pro->getConfig()->paymentAction)
            ->setNotifyUrl(Mage::getUrl('paypal/ipn/'))
            ->setInvNum($order->getIncrementId())
            ->setCurrencyCode(Mage::app()->getStore()->getCurrentCurrencyCode())//修改
            ->setPaypalCart(Mage::getModel('paypal/cart', array($order)))
            ->setIsLineItemsEnabled($this->_pro->getConfig()->lineItemsEnabled)
        ;
        if ($order->getIsVirtual()) {
            $api->setAddress($order->getBillingAddress())->setSuppressShipping(true);
        } else {
            $api->setAddress($order->getShippingAddress());
            $api->setBillingAddress($order->getBillingAddress());
        }

        // call api and get details from it
        $api->callDoExpressCheckoutPayment();

        $this->_importToPayment($api, $payment);
        return $this;
    }

    /**
     * Call DoAuthorize
     *
     * @param int $amount
     * @param Varien_Object $payment
     * @param string $parentTransactionId
     * @return Mage_Paypal_Model_Api_Abstract
     */
    protected function _callDoAuthorize($amount, $payment, $parentTransactionId)
    {
        $api = $this->_pro->resetApi()->getApi()
            ->setAmount($amount)
            ->setCurrencyCode(Mage::app()->getStore()->getCurrentCurrencyCode())//修改
            ->setTransactionId($parentTransactionId)
            ->callDoAuthorization();

        $payment->setAdditionalInformation($this->_authorizationCountKey,
            $payment->getAdditionalInformation($this->_authorizationCountKey) + 1
        );

        return $api;
    }

app/code/core/Mage/Paypal/Model/Cart.php

    /**
     * (re)Render all items and totals
     */
    protected function _render()
    {
        if (!$this->_shouldRender) {
            return;
        }

        // regular items from the sales entity
        $this->_items = array();
        foreach ($this->_salesEntity->getAllItems() as $item) {
            if (!$item->getParentItem()) {
                $this->_addRegularItem($item);
            }
        }
        end($this->_items);
        $lastRegularItemKey = key($this->_items);

        // regular totals
        $shippingDescription = '';
        if ($this->_salesEntity instanceof Mage_Sales_Model_Order) {
            $shippingDescription = $this->_salesEntity->getShippingDescription();
            $this->_totals = array(
                self::TOTAL_SUBTOTAL => $this->_salesEntity->getSubtotal(),//修改 
                self::TOTAL_TAX      => $this->_salesEntity->getTaxAmount(),//修改
                self::TOTAL_SHIPPING => $this->_salesEntity->getShippingAmount(),//修改
                self::TOTAL_DISCOUNT => abs($this->_salesEntity->getDiscountAmount()),//修改
            );
            $this->_applyHiddenTaxWorkaround($this->_salesEntity);
        } else {
            $address = $this->_salesEntity->getIsVirtual() ?
                $this->_salesEntity->getBillingAddress() : $this->_salesEntity->getShippingAddress();
            $shippingDescription = $address->getShippingDescription();
            $this->_totals = array (
                self::TOTAL_SUBTOTAL => $this->_salesEntity->getSubtotal(),//修改
                self::TOTAL_TAX      => $address->getTaxAmount(),//修改
                self::TOTAL_SHIPPING => $address->getShippingAmount(),//修改
                self::TOTAL_DISCOUNT => abs($address->getDiscountAmount()),//修改
            );
            $this->_applyHiddenTaxWorkaround($address);
        }
        $originalDiscount = $this->_totals[self::TOTAL_DISCOUNT];

    /**
     * Check the line items and totals according to PayPal business logic limitations
     */
    protected function _validate()
    {
        $this->_areItemsValid = false;
        $this->_areTotalsValid = false;

        $referenceAmount = $this->_salesEntity->getGrandTotal();//修改

        $itemsSubtotal = 0;
        foreach ($this->_items as $i) {
            $itemsSubtotal = $itemsSubtotal + $i['qty'] * $i['amount'];
        }
        $sum = $itemsSubtotal + $this->_totals[self::TOTAL_TAX];
        if (!$this->_isShippingAsItem) {
            $sum += $this->_totals[self::TOTAL_SHIPPING];
        }
        if (!$this->_isDiscountAsItem) {
            $sum -= $this->_totals[self::TOTAL_DISCOUNT];
        }

    /**
     * Add a usual line item with amount and qty
     *
     * @param Varien_Object $salesItem
     * @return Varien_Object
     */
    protected function _addRegularItem(Varien_Object $salesItem)
    {
        if ($this->_salesEntity instanceof Mage_Sales_Model_Order) {
            $qty = (int) $salesItem->getQtyOrdered();
            $amount = (float) $salesItem->getPrice();//修改
            // TODO: nominal item for order
        } else {
            $qty = (int) $salesItem->getTotalQty();
            $amount = $salesItem->isNominal() ? 0 : (float) $salesItem->getCalculationPrice();//修改
        }
        // workaround in case if item subtotal precision is not compatible with PayPal (.2)
        $subAggregatedLabel = '';
        if ($amount - round($amount, 2)) {
            $amount = $amount * $qty;
            $subAggregatedLabel = ' x' . $qty;
            $qty = 1;
        }

        // aggregate item price if item qty * price does not match row total
        if (($amount * $qty) != $salesItem->getRowTotal()) {//修改
            $amount = (float) $salesItem->getRowTotal();//修改
            $subAggregatedLabel = ' x' . $qty;
            $qty = 1;
        }

        return $this->addItem($salesItem->getName() . $subAggregatedLabel, $qty, $amount, $salesItem->getSku());
    }

    /**
     * Add "hidden" discount and shipping tax
     *
     * Go ahead, try to understand ]:->
     *
     * Tax settings for getting "discount tax":
     * - Catalog Prices = Including Tax
     * - Apply Customer Tax = After Discount
     * - Apply Discount on Prices = Including Tax
     *
     * Test case for getting "hidden shipping tax":
     * - Make sure shipping is taxable (set shipping tax class)
     * - Catalog Prices = Including Tax
     * - Shipping Prices = Including Tax
     * - Apply Customer Tax = After Discount
     * - Create a shopping cart price rule with % discount applied to the Shipping Amount
     * - run shopping cart and estimate shipping
     * - go to PayPal
     *
     * @param Mage_Core_Model_Abstract $salesEntity
     */
    private function _applyHiddenTaxWorkaround($salesEntity)
    {
        $this->_totals[self::TOTAL_TAX] += (float)$salesEntity->getHiddenTaxAmount();//修改
        $this->_totals[self::TOTAL_TAX] += (float)$salesEntity->getShippingHiddenTaxAmount();//修改
    }

app/code/core/Mage/Paypal/Model/Express/Checkout.php

    /**
     * Checkout with PayPal image URL getter
     * Spares API calls of getting "pal" variable, by putting it into cache per store view
     * @return string
     */
    public function getCheckoutShortcutImageUrl()
    {
        // get "pal" thing from cache or lookup it via API
        $pal = null;
        if ($this->_config->areButtonsDynamic()) {
            $cacheId = self::PAL_CACHE_ID . Mage::app()->getStore()->getId();
            $pal = Mage::app()->loadCache($cacheId);
            if (-1 == $pal) {
                $pal = null;
            } elseif (!$pal) {
                $pal = null;
                $this->_getApi();
                try {
                    $this->_api->callGetPalDetails();
                    $pal = $this->_api->getPal();
                    Mage::app()->saveCache($pal, $cacheId, array(Mage_Core_Model_Config::CACHE_TAG));
                } catch (Exception $e) {
                    Mage::app()->saveCache(-1, $cacheId, array(Mage_Core_Model_Config::CACHE_TAG));
                    Mage::logException($e);
                }
            }
        }

        return $this->_config->getExpressCheckoutShortcutImageUrl(
            Mage::app()->getLocale()->getLocaleCode(),
            $this->_quote->getGrandTotal(),//修改去掉base
            $pal
        );
    }

    /**
     * Reserve order ID for specified quote and start checkout on PayPal
     * @return string
     */
    public function start($returnUrl, $cancelUrl)
    {
        $this->_quote->collectTotals();

        if (!$this->_quote->getGrandTotal() && !$this->_quote->hasNominalItems()) {
            Mage::throwException(Mage::helper('paypal')->__('PayPal does not support processing orders with zero amount. To complete your purchase, proceed to the standard checkout process.'));
        }

        $this->_quote->reserveOrderId()->save();
        // prepare API
        $this->_getApi();
        $this->_api->setAmount($this->_quote->getGrandTotal())//修改去掉base
            //->setCurrencyCode($this->_quote->getBaseCurrencyCode())///修改为当前货币code
            ->setCurrencyCode(Mage::app()->getStore()->getCurrentCurrencyCode())
            ->setInvNum($this->_quote->getReservedOrderId())
            ->setReturnUrl($returnUrl)
            ->setCancelUrl($cancelUrl)
            ->setSolutionType($this->_config->solutionType)
            ->setPaymentAction($this->_config->paymentAction)

app/code/core/Mage/Sales/Model/Order/Payment.php

    /**
     * Capture the payment online
     * Requires an invoice. If there is no invoice specified, will automatically prepare an invoice for order
     * Updates transactions hierarchy, if required
     * Updates payment totals, updates order status and adds proper comments
     *
     * TODO: eliminate logic duplication with registerCaptureNotification()
     *
     * @return Mage_Sales_Model_Order_Payment
     * @throws Mage_Core_Exception
     */
    public function capture($invoice)
    {
        if (is_null($invoice)) {
            $invoice = $this->_invoice();
            $this->setCreatedInvoice($invoice);
            return $this; // @see Mage_Sales_Model_Order_Invoice::capture()
        }
        $amountToCapture = $this->_formatAmount($invoice->getGrandTotal());//修改
        $order = $this->getOrder();

    /**
     * Decide whether authorization transaction may close (if the amount to capture will cover entire order)
     * @param float $amountToCapture
     * @return bool
     */
    protected function _isCaptureFinal($amountToCapture)
    {
        $amountToCapture = $this->_formatAmount($amountToCapture, true);
        $orderGrandTotal = $this->_formatAmount($this->getOrder()->getGrandTotal(), true);//修改
        if ($orderGrandTotal == $this->_formatAmount($this->getAmountPaid(), true) + $amountToCapture) {//修改
            if (false !== $this->getShouldCloseParentTransaction()) {
                $this->setShouldCloseParentTransaction(true);
            }
            return true;
        }
        return false;
    }

app/code/core/Mage/Core/Model/Store.php

    /**
     * Round price
     *
     * @param mixed $price
     * @return double
     */
    public function roundPrice($price)
    {
    	if(Mage::app()->getStore()->getCurrentCurrencyCode()=='JPY'){
       		return round($price,0);
		}else{
			return round($price, 2);
		}
    }

    /**
     * Format price with currency filter (taking rate into consideration)
     *
     * @param   double $price
     * @param   bool $includeContainer
     * @return  string
     */
    public function formatPrice($price, $includeContainer = true)
    {
        if ($this->getCurrentCurrency()) {
        	if(Mage::app()->getStore()->getCurrentCurrencyCode()=='JPY'){
            	return $this->getCurrentCurrency()->format($price, array('precision'=>0), $includeContainer);
			}else{
				return $this->getCurrentCurrency()->format($price, array(), $includeContainer);
			}
        }
        return $price;
    }