Magento – Paypal Express with coupon and custom discount

paypal-express

Paypal Express works fine if there's no coupon applied. If there's a coupon applied, it fails with the usual #10413 error "totals of the cart item amounts do not match order amounts".

I have a requirement to customize the discount logic so that the discounts are reflected in the unit prices and not in the standard lump sum. There is a rounding issue when the quantities are large and Paypal will reject the payment. After hacking the Paypal module code, I can send a correct AMT = ITEMAMT + SHIPPING.

However, after returning from the Paypal payment confirmation page to Magento, for some reason the error #10413 appears again because AMT is changed (not the AMT that was sent to Paypal). I am not able to figure out why or how AMT is changed.

I am using Magento community version 1.8.1.0.

Best Answer

I spent 2 days but still could not find out who changed the value in AMT.

The following hack works for now. In app/code/core/Mage/Paypal/Model/Api/Nvp.php, change the method callDoExpressCheckoutPayment():

 ...
 $this->_exportLineItems($request);
 $finalTotal = $request['ITEMAMT'] + $request['SHIPPINGAMT'];
 if (sprintf('%.2F', $request['AMT']) != sprintf('%.2F', $finalTotal)) {
     $request['AMT'] = $finalTotal;
 }

Related Solutions

Magento – PayPal#10413: Transaction refused because of an invalid argument

The issue you faced is related to Magento bug due to which the logic of actions of TAX calculation is performed in the wrong order.

To resolve the problem, you just need to navigate to file:

app/code/core/Mage/Sales/Model/Config/Ordered.php

find _getSortedCollectorCodes() function and replace with below code

protected function _getSortedCollectorCodes()
    {
        if (Mage::app()->useCache('config')) {
            $cachedData = Mage::app()->loadCache($this->_collectorsCacheKey);
            if ($cachedData) {
                return unserialize($cachedData);
            }
        }
        $configArray = $this->_modelsConfig;
        // invoke simple sorting if the first element contains the "sort_order" key
        reset($configArray);
        $element = current($configArray);
        if (isset($element['sort_order']) && false) {
            uasort($configArray, array($this, '_compareSortOrder'));
            $sortedCollectors = array_keys($configArray);
        } else {

            $sortedCollectors = array_keys($configArray);

            foreach ($configArray as $code => &$data) {
                foreach ($data['before'] as $positionCode) {
                    if (!isset($configArray[$positionCode])) {
                        continue;
                    }
                    if (!in_array($code, $configArray[$positionCode]['after'], true)) {
                        // Also add additional after condition for related total,
                        // to keep it always after total with before value specified
                        $configArray[$positionCode]['after'][] = $code;
                    }
                    $currentPosition = array_search($code, $sortedCollectors, true);
                    $desiredPosition = array_search($positionCode, $sortedCollectors, true);
                    if ($currentPosition > $desiredPosition) {
                        // Only if current position is not corresponding to before condition
                        array_splice($sortedCollectors, $currentPosition, 1); // Removes existent
                        array_splice($sortedCollectors, $desiredPosition, 0, $code); // Add at new position
                    }
                }
            }

            // Sort out totals with after position specified
            foreach ($configArray as $code => &$data) {
                $maxAfter = null;
                $currentPosition = array_search($code, $sortedCollectors, true);
                foreach ($data['after'] as $positionCode) {
                    $maxAfter = max($maxAfter, array_search($positionCode, $sortedCollectors, true));
                }
                if ($maxAfter !== null && $maxAfter > $currentPosition) {
                    // Moves only if it is in front of after total
                    array_splice($sortedCollectors, $maxAfter + 1, 0, $code); // Add at new position
                    array_splice($sortedCollectors, $currentPosition, 1); // Removes existent
                }
            }
        }

        if (Mage::app()->useCache('config')) {
            Mage::app()->saveCache(serialize($sortedCollectors), $this->_collectorsCacheKey, array(
                    Mage_Core_Model_Config::CACHE_TAG
                )
            );
        }
        return $sortedCollectors;
    }

Note : Please override core file. Do not change core file. Clear cache

Magento – PayPal gateway has rejected request 10413

You have the subtotal:

[ITEMAMT] => 21.97 It doesn't correspond to the total of all items: [L_AMT0] => 19.97 [L_AMT1] => 0.00 That's the reason why PayPal is showing the error.

Here is how the function should look in the observer:

public function updatePaypalTotal(Varien_Event_Observer $observer)
{
    $cart = $observer->getEvent()->getPaypalCart();

    $donationAmount = $cart->getSalesEntity()->getDonationAmount();
    if ($donationAmount > 0) {
        $cart->addItem('Additional Fees', 1, $donationAmount, 'donation');
    }

    return $this;
}

Best Answer

Related Solutions

Magento – PayPal#10413: Transaction refused because of an invalid argument

Magento – PayPal gateway has rejected request 10413

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