@Vasmir

For this, you can override uc_empty_cart() function with theme_uc_empty_cart(); which returns your custom message on empty cart page.

You can get continuous shopping cart URL from Store > cart setting using variable_get('uc_continue_shopping_url', '').

Ex.

  // Default function from uc_cart.module
  function theme_uc_empty_cart() {
    return '<p>'. t('There are no products in your shopping cart.') . '</p><a href="'.variable_get('uc_continue_shopping_url', '').'" rel="continuous-shopping">continuous shopping</a>';
  }

For this, you can override uc_empty_cart() function with theme_uc_empty_cart(); which returns your custom message on empty cart page.

You can get continuous shopping cart URL from Store > cart setting using variable_get('uc_continue_shopping_url', '').

Example:

  // Default function from uc_cart.module
  function theme_uc_empty_cart() {
    return '<p>'. t('There are no products in your shopping cart.') . '</p><a href="'.variable_get('uc_continue_shopping_url', '').'" rel="continuous-shopping">continuous shopping</a>';
  }