Update the Price of an item when adding to the cart

Question

So here's my project. Make our giftcard integration purchasable.

Basically I need to get an "Enter Custom Amount" input field to update the price of the item. What I have been told by our architect is that I should Update the MyCompany_GiftCard_Model_Product_Type_GiftCard class to extend Mage_Catalog_Model_Product_Type_Abstract

then override the _prepareProduct Method to use the value from the custom amount if defined. So. I made this method:

protected function _prepareProduct(Varien_Object $buyRequest, $product, $processMode) {
 $result = parent::_prepareProduct($buyRequest, $product, $processMode);
 $oRide = $buyRequest->getOverrideAmount();
 $stn_amt = $buyRequest->getAmount();
 $productGiftCard = $buyRequest->getGiftCard();
 if(isset($oRide) && ($oRide != '') && ($oRide != 0) && ($oRide != null)){
 $result[0]->addCustomOption('giftcard_amount', $oRide);
 }else{
 $result[0]->addCustomOption('giftcard_amount', $amount);
 }
 if (!empty($productGiftCard)) {
 return $result;
 } 
 return Mage::helper('catalog')->__('Please specify the required options of product.');
}

Then I was told to update the getFinalPrice() method to accept the new value from MyCompany_GiftCard_Model_Product_Type_GiftCard_Price

public function getFinalPrice($qty = null, $product)
{
 $finalPrice = parent::getFinalPrice($qty, $product);
 $amount = $product->getCustomOption('giftcard_amount'); // its an object or false
 if($amount) {
 $finalPrice = $qty * $amount->getValue();
 }
 // echo '<br>finalPrice: '.$finalPrice;
 $product->setFinalPrice($finalPrice);
 // echo $product->getData('final_price');
 // Mage_Sales_Model_Quote_Item_Abstract
 return max(0, $product->getData('final_price'));
}

Here's the thing. If you do: echo $product->getData('final_price')); It totally equals the price I want to be! If the custom amount is set, final_price == custom amount!

Does anyone have any ideas where I'm going wrong and why the GetFinalPrice is not the price for the item in checkout?

(I'm rather new to Magento, 3 months-ish, but our architect was quite adamant that updating the getFinalPrice() method directly update the price in the cart! He's unavailable right now, and I have a deadline.

• Haim: Kudos for a well written question. You should add that your issue is that in cart the price of the item is not your custom amount (assuming I understood you correctly). You need to set that price for the quote - when the item is added to cart

Answer 1

You are correct that getFinalPrice is the correct place, however I think you may be missing some calls to 'set it' correctly.

Have a look at this github file:

https://github.com/ProxiBlue/GiftPromo/blob/master/app/code/community/ProxiBlue/GiftPromo/Model/Product/Type/Gift/Simple/Price.php

This is from a GiftPromo module I wrote aeons ago. It basically does teh same thing - The product (proper product in catalog, with price) can be gifted (no new sku is used, the actual catalog product, and SKU , is gifted, BUT the price is adapted to what i set in admin for that product gifting rule)

In my code you will see I get the price for the item, from a value stored in info_buyRequest ($giftedPrice = $buyRequest->getGiftedPrice();) - I literally set the 'updated price' to the info_BuyRequest upon add-to-cart, and then set the finalPrice, based on that value, in the given routine. (this is all handled in lines 23-46, with teh value resulting in $giftedPrice

Now, if you check my code, there are a couple of things I do, that you don't (I have not used/worked with this moule in years, so I don't recall 100% what they all do)

$finalPrice = $this->_applyOptionsPrice($product, $qty, $finalPrice);

$product->setCalculatedFinalPrice($finalPrice);

I highly suspect that last one is what you are misisng.

I hope this helps in some way.

PS: You will find a Price.php class for all product types in the parent folder:

https://github.com/ProxiBlue/GiftPromo/tree/master/app/code/community/ProxiBlue/GiftPromo/Model/Product/Type/Gift

• dustbuster: This is a pretty great answer. Thanks! I actually figured out the issue. There was an observer that changing the price right before it updated the cart price! Somehow I missed it. Again, I am new to Magento, so I don't always pick up on everything. It seems that the case where adding a customOption was already anticipated and had a 'code' already set up in the observer. But I will indeed go through your module and have a look around. Thank you @ProxiBlue +1 I will also post a more explicit explanation shortly with code examples.

Answer 2

I was getting frustrated, so I just did a general search of the code for ['amount'] and this is what I found inside of app/code/local/Company/Giftcard/Model/Observer.php:

public function checkoutCartProductAddAfter(Varien_Event_Observer $observer)
{
 // set custom price for the quote item
 $item = $observer->getQuoteItem();
 $product = $item->getProduct();
 if ($product->isGiftCard()) {
 if ($customPrice = $product->getData('custom_option')) {
 $item->setCustomPrice($customPrice);
 $item->setOriginalCustomPrice($customPrice);
 }
 // save reorder data
 $action = Mage::app()->getFrontController()->getAction();
 if (!$action) {
 return;
 }
 if ($customWishListPrice = $item->getOptionByCode('giftcard_amount')) {
 $item->setCustomPrice($customWishListPrice->getValue());
 $item->setOriginalCustomPrice($customWishListPrice->getValue());
 }
 if ($action->getFullActionName() == 'sales_order_reorder') {
 $item = $observer->getQuoteItem();
 $options = $item->getBuyRequest()->getGiftCard();
 parse_str($options, $optionsArray);
 if (count($optionsArray)) {
 $item->setPrice($optionsArray['amount']);
 unset($optionsArray['amount']);
 $additionalOptions = array();
 foreach ($optionsArray as $optionCode => $value) {
 $additionalOptions[] = array(
 'label' => $optionCode,
 'value' => $value,
 );
 }
 $item->addOption(array(
 'code' => 'additional_options',
 'value' => serialize($additionalOptions)
 ));
 }
 }
 }
}

The part that was causing me the headache was

if ($customPrice = $product->getData('custom_option')) {
 $item->setCustomPrice($customPrice);
 $item->setOriginalCustomPrice($customPrice);
}

So I changed it to

if ($customPrice = $product->getData('giftcard_amount')) {
 $item->setCustomPrice($customPrice);
 $item->setOriginalCustomPrice($customPrice);
}

and it worked! There were also some other supporting observer methods that I had to change the custom_amount to giftcard_amount. But this example is enough to support my point. This module was already coded to accept a custom_amount for the giftcard, but I didn't know it!

I thought I did everything right but somehow 'magic gremlins' were getting ahold of my request and swapping around the amounts and submitting them to the cart. But it was just an observer I hadn't noticed!