Problem with update function

[adamjblakey]

Hi,

I have a function which updates a cart but it is not working correctly. Basically if i have e.g.

2 x Red Shoes
3 x Blue Shorts

And then i change the qty of the blue shorts to 4 and pass to the update function it just completely removes the first lot of items in the list e.g. the 2 x red shorts.

The data is stored in a session like so:

58:|Red Shoes|14.95,58:|Red Shoes|14.95,56:|Blue Shorts|8.95,56:Size|Blue Shorts|8.95,56:Size|Blue Shorts|8.95

Here is the code for the function:

case 'update':
    if ($cart) {
        $newcart = '';
        foreach ($_POST as $key=>$value) {
            if (stristr($key,'qty')) {
                $id = str_replace('qty','',$key);
                $items = ($newcart != '') ? explode(',',$newcart) : explode(',',$cart);
                $newcart = '';
                foreach ($items as $item) {
                    if ($id != $item) {
                        if ($newcart != '') {
                            $item = '';
                            $newcart .= ','.$item;
                        } else {
                            $item = '';
                            $newcart = $item;
                        }
                    }
                }
                for ($i=1;$i<=$value;$i++) {
                    if ($newcart != '') {
                        $newcart .= ','.$id;
                    } else {
                        $newcart = $id;
                    }
                }
            }
        }
    }
    $cart = preg_replace("/_/i", " ", preg_replace("/(\d+)_(\d+)/i", "$1.$2", $newcart));
 
 
    break;
}
 

Thanks in advance,
Adam

[Atli]

Hi.

Why do you serialize the items into the session like that?

This would be much much easier to manage if you had each item in a separate session value. For example, a function to add items could look like this:

<?php
function addItem($itemID, $quantity) 
{
    if(!isset($_SESSION['chart'][$itemID])) {
        $_SESSION['chart'][$itemID] = 0;
    }
    $_SESSION['chart'][$itemID] += $quantity;
}
?>
 

The $_SESSION variable is an array, and you can treat it as such.
The function just adds elements for each product, and stores the amount of that particular product you want to have in the chart.

Then, when you need to list the items in the chart, you just use a foreach loop on the $_SESSION['chart'] element.

I assume the price and other such info is listed in a database somewhere?
So there is no real reason to store that in the session to, is there?