I have been working on showing custom options of simple product for grouped product. I am done with initial phase of allowing required custom option product and then showing it on frontend. I have modified checkout/cart/add to add products with custom option to cart. This is also working fine. But I see products are being added twice to cart. Once with custom option and another one without custom option. I have debugged app/code/core/Mage/Catalog/Model/Product/Type/Grouped.php . Here, protected function _prepareProduct(Varien_Object $buyRequest, $product, $processMode) is responsible for adding product to cart. I tried adding custom option values of products from here. But couldn't succeed.

Note:- Here I am not trying to create new custom options. I just want to set the values of custom option.

Any help will be appreciated. Thanks in advance.

  • Please share your controller code and how you call it
    – PЯINCƎ
    Jul 11, 2018 at 23:11
  • It will be difficult to share my code. But can you explain which code is responsible for adding grouped product to cart in Magento 1?? Jul 12, 2018 at 15:05

2 Answers 2


I have done it.

$cart->addProduct($product, $params);

This code was adding the products again. As I was adding them with custom option. I forgot to put this in condition. And both were working simultaneously.


if i am not mistaken, i think you want to add custom options when product added to cart.

to add your custom option you need to do this: call a event : catalog_product_load_after


then in namespace/modelname/methodname

add this code:

$additionalOptions = array();
$additionalOptions[ ] = array(
    'label' => 'Print Method',
    'value' => $print_type,

$observer->getProduct()->addCustomOption('additional_options', serialize($additionalOptions));

and if you want to update the values just call same function with different additional array values.

hope this clear your doubt. feel free to ask questions,

thank you.

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