USPS Shipping Module [Support Thread]

[HeleneWallis]

If you're using USPS K11a, then including a modified version of the autoloaded observer example (present in the zip-files /extras sub-directory) should disable media-mail unless all products in the cart are from category 15:

            case 'NOTIFY_USPS_UPDATE_OR_DISALLOW_TYPE':
                // -----
                // Disallow "Media Mail" unless all products in the cart have their master_categories_id within category 15.
                //
                if (stripos($p1, 'Media Mail') !== false) {
                    $chk_media = 0;

                    $chk_media += $_SESSION['cart']->in_cart_check('master_categories_id', '15');
                    if ($chk_media == $_SESSION['cart']->count_contents()) {
                        $p2 = false;
                    }
                }
                break;

If that books category contains sub-categories, you'll need to add additional lines to check for the presence of each of the sub-categories.

Thanks, I can use that too.