WordPress Shopping Cart: Redirect/Hosted Payment Gateway step 1

gistfile1.php

// WordPress Shopping Cart: Redirect/Hosted Payment Gateway step 1
// http://tribulant.com/docs/wordpress-shopping-cart-plugin/7190

function gateway_activation_hook() {
    require_once ABSPATH . 'wp-admin' . DS . 'admin-functions.php';
    $path = 'wp-checkout' . DS . 'wp-checkout.php';
 
    if (!is_plugin_active(plugin_basename($path))) {
        _e('You must have the Shopping Cart plugin installed and activated in order to use this.', "checkout-gateway");
        exit(); die();
    } else {
        $required = "X.X";
        $plugin_data = get_plugin_data(WP_CONTENT_DIR . DS . 'plugins' . DS . $path);
        $plugin_version = $plugin_data['Version'];
 
        $versiongood = false;
        if (version_compare($plugin_version, $required) >= 0) {
            $versiongood = true;
        }
 
        if ($versiongood == true) {
            add_option('wpcogateway_title', __('Credit and debit card payments with Gateway', "checkout-gateway"));
        } else {
            echo '<span style="font-family:sans-serif;">' . sprintf(__('The Gateway extension requires the Shopping Cart plugin v%s at least.', "checkout-gateway"), $required) . '</span>';
            exit(); die();
        }
    }
 
    return true;
}
 
register_activation_hook(__FILE__, 'gateway_activation_hook');