Here is the code
<?php session_start(); ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="description" content="PHP Shopping Cart Using Sessions" />
<meta name="keywords" content="shopping cart tutorial, shopping cart, php, sessions" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" media="all" href="/style/style.css" type="text/css" />
<title>Cart</title>
<?php
include("header_1.php");
include ("Connections/databse.php");
include("header.php");
include("heading.php");
?>
</head>
<body>
<div id='content'><div id='output'>
<?php
$product_id = $_GET['id'] ; //the product id from the URL
$action = $_GET['action']; //the action from the URL
//if there is an product_id and that product_id doesn't exist display an error message
if($product_id && !productExists($product_id)) {
die("Error. Product Doesn't Exist");
}
switch($action) { //decide what to do
case "add":
$_SESSION['cart'][$product_id]++; //add one to the quantity of the product with id $product_id
break;
case "remove":
$_SESSION['cart'][$product_id]--; //remove one from the quantity of the product with id $product_id
if($_SESSION['cart'][$product_id] == 0) unset($_SESSION['cart'][$product_id]); //if the quantity is zero, remove it completely (using the 'unset' function) - otherwise is will show zero, then -1, -2 etc when the user keeps removing items.
break;
case "empty":
unset($_SESSION['cart']); //unset the whole cart, i.e. empty the cart.
break;
}
?>
<?php
if(isset($_SESSION['cart'])) { //if the cart isn't empty
//show the cart
echo "<table border=\"1\" padding=\"3\" width=\"100%\">"; //format the cart using a HTML table
//iterate through the cart, the $product_id is the key and $quantity is the value
foreach($_SESSION['cart'] as $product_id => $quantity) {
//get the name, description and price from the database - this will depend on your database implementation.
//use sprintf to make sure that $product_id is inserted into the query as a number - to prevent SQL injection
$sql = sprintf("SELECT horse, text, price FROM database WHERE id = %d;",
$product_id);
$result = mysql_query($sql);
//Only display the row if there is a product (though there should always be as we have already checked)
if(mysql_num_rows($result) > 0) {
list($name, $description, $price) = mysql_fetch_row($result);
echo "<tr>";
//show this information in table cells
echo "<td align=\"center\">$name</td>";
//along with a 'remove' link next to the quantity - which links to this page, but with an action of remove, and the id of the current product
echo "<td align=\"center\">$price</td>";
echo "<td align=\"center\"> <a href=\"$_SERVER[PHP_SELF]?action=remove&id=$product_id\">Remove from shortlist</a></td>";
echo "</tr>";
}
}
//show the total
//show the empty cart link - which links to this page, but with an action of empty. A simple bit of javascript in the onlick event of the link asks the user for confirmation
echo "<tr>";
echo "<td colspan=\"3\" align=\"right\"><a href=\"$_SERVER[PHP_SELF]?action=empty\" onclick=\"return confirm('Are you sure?');\">Empty Cart</a></td>";
echo "</tr>";
echo "</table>";
}else{
//otherwise tell the user they have no items in their cart
echo "You have no items in your shortlist.";
}
//function to check if a product exists
function productExists($product_id) {
//use sprintf to make sure that $product_id is inserted into the query as a number - to prevent SQL injection
$sql = sprintf("SELECT * FROM database WHERE id = %d;",
$product_id);
return mysql_num_rows(mysql_query($sql)) > 0;
}
?>
<a href="products_test.php">Continue Browsing</a>
</div></div>
<?php include ("footer.php"); ?>
</body>
</html>
Works perfectly but when I go to the empty cart I get this message
Notice: Undefined index: id in /home/xxxx/public_html/cart_test.php on line 26
line 26 is
$product_id = $_GET['id'] ;
When I add something to the cart I get this message.
Notice: Undefined index: cart in /home/xxxx/public_html/cart_test.php on line 37
Notice: Undefined offset: 2361 in /home/xxxx/public_html/cart_test.php on line 37
line 37 is
$_SESSION['cart'][$product_id]++;
I'm thinking I have to do some kind of isset thing but everything I've tried so far just creates other errors.
Some suggestions would be appreciated.
Thanks
