Commerce: is there something in the basket?

Question

Is there a global variable of sorts that can be used as a bool to determine if something is in the basket?

Answer 1

This is what i use :)

function items_on_cart(){
  global $user;
  $cart = commerce_cart_order_load($user->uid);
  $line_items = count($cart->commerce_line_items) ? true : false;
  return $line_items;
}

Answer 2

Commerce Cart has the following function commerce_cart_order_session_exists() which you could probably use to set a boolean value.

Checks to see if any order ID or a specific order ID exists in the session.

To answer your question directly though, there is no global variable to detect carts.