undefined index $_COOKIE

Question

I have a shopping cart which I store in a cookie. The cookie 'shopping_cart' is set once an item is added onto the cart.

function shopping_cart_add(){

      if(isset($_COOKIE['shopping_cart'])){
          $cookie_data = $_COOKIE['shopping_cart'];
          $cart_data = json_decode($cookie_data, true);
      }else{
          $cart_data = array();
      }
         $data = array(
        "cart_id" => 1,
        "product_id" => $this->input->post('product_id'),
        "product_name" => $this->input->post('product_name'),
        "product_price" => $this->input->post('product_price'),
        "quantity" => $this->input->post('quantity'),
        "options" => $this->input->post('options'),
        "description" => $this->input->post('description'),
        "image" => $this->input->post('image')
        );
         $cart_data[] = $data;

      $item_data = json_encode($cart_data);
      setcookie('shopping_cart',$item_data,time() + (86400 * 30));
      $_COOKIE['shopping_cart'] = $item_data;
    }

I am having a problem with when the user wants to remove an item from cart. I am using codeigniter framework but not its inbuilt cookies.

The following is the code in my view for deleting an item:

<td><a href="<?php echo base_url('designs/delete/');?><?=$values['product_id'];?>" type="button" class="btn btn-default btn-sm">Delete</a></td>

The following is the code in my controller for deleting an item:

function delete($delete_id){
        $cookie_data = $_COOKIE['shopping_cart'];
        $cart_data = json_decode($cookie_data, true);
        foreach ($cart_data as $key => $value) {
            if ($cart_data[$key]['product_id'] == $delete_id) {
                unset($cart_data[$key]);
                $item_data = json_encode($cart_data);
                setcookie('shopping_cart',$item_data,time() + (86400 * 30));
                header("location:/category/cart_summary.php?remove=1");
            }
        }
    }

However I keep getting an error when I click the delete button.

Undefined variable $_COOKIE['shopping_cart']

Yet when I check my browser it show the cookie exists. What could be the problem?? I have already checked similar questions on stack pertaining to this issue but none has helped. This includes: undefined index for cookie in some browsers PHP Undefined Index When Checking Cookie Value And Cookie Exists

Answer 1

This probably happens because you didn't explicitly mentions on what path the shopping_cart cookies will be saved. Try to add a 4th parameter (path) at each setcookie :

setcookie('shopping_cart',$item_data,time() + (86400 * 30), '/');