For bootstrap 4, hidden is invisible class.

diff --git a/src/formelement.c b/src/formelement.c
index 9934afb2383e4b77104675c4e4232a8aa35d97d2..f8dc04f666b60ec920e3e24c9f696cdd8f1b16cc 100644 (file)
--- a/src/formelement.c
+++ b/src/formelement.c
@@ -193,7 +193,14 @@ gchar
 
        if (!zak_form_element_get_visible (ZAK_FORM_ELEMENT (element)))
                {
-                       g_string_append (str, " hidden");
+                       if (g_strcmp0 (priv->bootstrap_version, "4") == 0)
+                               {
+                                       g_string_append (str, " invisible");
+                               }
+                       else
+                               {
+                                       g_string_append (str, " hidden");
+                               }
                }
 
        messages = zak_form_element_get_messages (ZAK_FORM_ELEMENT (element));