Setting shopping cart session arrays to include more than just quantity

[brando]

Hello all-

I am trying to store more info about each product in a session array.
The current shopping cart script that I am using is very basic. It totals the item price and adds up the quantity for each product.

I would like to include a discount field as well as the quantity. Calculating this is the easy part. Setting a session variable with : the ProductID, the Quantity, and the Discount is where the trouble begins.

Is this a multidemenisional array? It seems like it might be. How do I set the vaiable and then break it out.

View the folowing code to see what I am talking about.
First Notice how the tet box for the quantity is named after the product ID.
I put the discuont field in there but don't know what to do with it.

foreach ($cart as $productID => $qty)
{
  $product = get_product_details($productID);
  $discount = $HTTP_SESSION_VARS['discount'];
	    echo '<tr>';
		echo '<td align=left><a href="product_detail.php?productID='.$productID.'">'.$product['title'].'</a></td>';
		echo '<td align=center>$'.number_format($product['price'], 2).'</td>';
		echo "<td align=center><input type=\"text\" name=\"$productID\" value=\"$qty\" size=\"2\"></td>";
		echo "<td align=center><input type=\"text\" name=\"discount[]\" value=\"$discount\" size=\"4\">%</td>";
		echo '<td align=right>$'.number_format($product['price']*$qty,2).'</td>';
    	echo '</tr>';
}

So, that's that part.
Now here is the code that adds a product to the cart (adds to the session vaiable called 'cart'). This is where the quantity is set as well.

if($new)
  {
		//new item selected
		if(!isset($HTTP_SESSION_VARS['cart']))
		{
			  $HTTP_SESSION_VARS['cart'] = array();
			  $HTTP_SESSION_VARS['items'] = 0;
			  $HTTP_SESSION_VARS['total_price'] ='0.00';
		}
			if(isset($HTTP_SESSION_VARS['cart'][$new])) {
				$HTTP_SESSION_VARS['cart'][$new]++; 
			} else  {
				$HTTP_SESSION_VARS['cart'][$new] = 1;
			}

		$HTTP_SESSION_VARS['total_price'] = calculate_price($HTTP_SESSION_VARS['cart']);
		$HTTP_SESSION_VARS['items'] = calculate_items($HTTP_SESSION_VARS['cart']);
  }


if(isset($HTTP_POST_VARS['save']))
{      

	///////////////////
		$i=0;
		foreach ($HTTP_SESSION_VARS['cart'] as $productID => $qty)	{
			if($HTTP_POST_VARS[$productID]=='0')  {
				unset($HTTP_SESSION_VARS['cart'][$productID]);
			}  else  {
			   $HTTP_SESSION_VARS['cart'][$productID] = $HTTP_POST_VARS[$productID];
			   $HTTP_SESSION_VARS['cart'][$product]['discount'] = $HTTP_POST_VARS[$discount];

		   echo $HTTP_SESSION_VARS['cart'][$discount].'<br>';
		}
	$i++;
	}	  
		$HTTP_SESSION_VARS['discount'] = calculate_discount($HTTP_SESSION_VARS['cart']);
		$HTTP_SESSION_VARS['items'] = calculate_items($HTTP_SESSION_VARS['cart']);
		$HTTP_SESSION_VARS['total_price'] = calculate_price($HTTP_SESSION_VARS['cart']);
}

  if($HTTP_SESSION_VARS['cart']&&array_count_values($HTTP_SESSION_VARS['cart'])) {
		display_cart($HTTP_SESSION_VARS['cart']);
	  } else  {
		echo '<p>There are no items in your cart</p>';
		echo '<hr />';
  }

Here are the functions that set the session vaiables as well. Sorry to post so much, but better than describing.

 
function calculate_price($cart)
{
  // sum total price for all items in shopping cart
  $price = 0.0;
  if(is_array($cart))
  {
		foreach($cart as $productID => $qty) {  

			//echo $productID.'---'.$qty.'<br>';
			  $result = mysql_query("select price from products where productID='$productID'");
				  if ($result) {
					$item_price = mysql_result($result, 0, 'price');
					$price +=$item_price*$qty;
			 	  }
		}
  }
  return $price;
}



function calculate_items($cart)
{
  // sum total items in shopping cart
  $items = 0;
  if(is_array($cart))
  {
			foreach($cart as $productID => $qty)   {  

			  $items += $qty;
			}
  }
  return $items;
}


function calculate_discount($cart)
{
  // sum total items in shopping cart    while (list ($key, $value) = each ($cart[$productID]['discount']))
  $discount = 0;
  if(is_array($cart))
  {
		foreach($cart as $productID => $disc)   {  

			$discount += $disc;
			}
  }
 return $discount;
}

Any ideas?
Please help.
Thank you!
Brandon

[zhabala]

if(isset($HTTP_POST_VARS['save'])) 
{       

    /////////////////// 
        $i=0; 
        foreach ($HTTP_SESSION_VARS['cart'] as $productID => $qty)    { 

/// Here it should be probably $HTTP_POST_VARS['productID'] because it means the value of the passed variable named 'productID' and in new versions of PHP you should use the $_POST global array instead of $HTTP_POST_VARS
            if($HTTP_POST_VARS[$productID]=='0')  { 
                unset($HTTP_SESSION_VARS['cart'][$productID]);

        }  else  { 
/// the problem is probably here
/// once you are using [$productID]
/// once you are using [$product]
/// and in the echo statement you don't use [$productID]  index at all     

           $HTTP_SESSION_VARS['cart'][$productID] = $HTTP_POST_VARS[$productID]; 
/// here also you should use $HTTP_POST_VARS['discount'] instead of  the $HTTP_POST_VARS[$discount] because $discount contains no value probably
               $HTTP_SESSION_VARS['cart'][$product]['discount'] = $HTTP_POST_VARS[$discount]; 


           echo $HTTP_SESSION_VARS['cart'][$discount].'<br>'; 
        } 
    $i++; 
    }       
        $HTTP_SESSION_VARS['discount'] = calculate_discount($HTTP_SESSION_VARS['cart']); 
        $HTTP_SESSION_VARS['items'] = calculate_items($HTTP_SESSION_VARS['cart']); 
        $HTTP_SESSION_VARS['total_price'] = calculate_price($HTTP_SESSION_VARS['cart']); 
}