Customizing the cart of "OpenCart" - php

Question

I am trying to make a few changes to the actual cart in OpenCart.
As for now when adding a product to the cart information will be shown the following way:
Product1 Amount:
Size: XL 2
And a new row is created if the same product, but with a different size, is added to the cart.
My wish is to get the following design of the cart
Product1 S M L XL
1 2
So, that each product will only create one, single line and then show the correct amount under the corresponding size categories.
This is my code so far:
<?php
$saveName = array();
$sizesArray = array("S","M","L","XL");
$x = 0;
if($products || $vouchers) {
foreach ($products as $product){
foreach ($product['option'] as $option) {
$option['value'];
}
$saveName[$x] = $product['name'].'|'.$option['value'].'|'.$product['quantity'];
$seperateValues = explode("|",$saveName[$x]);
?>
<tr>
<td class="image"><?php if ($product['thumb']) { ?>
<img src="<?php echo $product['thumb']; ?>" alt="<?php echo $product['name']; ?>" title="<?php echo $product['name']; ?>" />
<?php } ?></td>
<td class="name"><?php echo $product['name']; ?></td>
<?php
foreach($sizesArray as $sizes){
if($sizes == $seperateValues[1]){
echo '<td>'.$seperateValues[0].' '.$seperateValues[2].'</td>';
}
else{
echo '<td>0</td>';
}
}
?>
<td class="total"><?php echo $product['total']; ?></td>
<td class="remove">Remove</td>
</tr>
<?php
$x++;
}
?>
The code formats the amount under the right category, but I can't get it to produce only one row for each product. Any help is much appriciated.
Thanks!

Answer 1

Modifying the template is not going to do the job, because Opencart internally stores products in array in a format product_id:serialized_array_of_options, so products with the same id but different option combinations are stored separately. You can see that in /system/library/cart.php, in the getProducts method:
foreach ($this->session->data['cart'] as $key => $quantity) {
$product = explode(':', $key);
$product_id = $product[0];
$stock = true;
// Options
if (isset($product[1])) {
$options = unserialize(base64_decode($product[1]));
} else {
$options = array();
}
So to achieve, what you want, you will have make changes to the way Cart class stores products in the session.