Re: Gtk::Builder and item id

[Christian Schoenebeck <schoenebeck linuxsampler org>]

On Montag, 6. November 2017 15:38:32 CET Christian Schoenebeck wrote:
>     uiBuilder = Gtk::Builder::create();
>     Glib::ustring ui_info =
>         "<interface>"
>         "  <menu id='menu-PopupMenuInsideDimRegion'>"
>         "    <section>"
>         "      <item id='item-split'>"
[snip]
>         "      </item>"
>         "    </section>"
>         "  </menu>"
>         "</interface>";
>     uiBuilder->add_from_string(ui_info);
[snip]
> Now the problem is, that add_from_string() throws the following exception:
>
>       Attribute "id" invalid for element "item"
>
> Is that a bug?

Ok, after reviewing the relevant Gtk+ code, the current Gtk Builder XML parser 
clearly does not accept an "id" attribute for "item" elements:

        https://github.com/GNOME/gtk/blob/master/gtk/gtkbuilder-menus.c
        (Line 107) :

        if (COLLECT (G_MARKUP_COLLECT_INVALID, NULL))

 which contradicts to both, what the Gtk+ docs say, quote:

         "Objects may be given a name with the “id” attribute, which allows the 
        application to retrieve them from the builder with 
        gtk_builder_get_object()."
        ( https://developer.gnome.org/gtk3/stable/GtkBuilder.html )

as well as contradicts to the format's schema file:

        https://github.com/GNOME/gtk/blob/master/gtk/gtkbuilder.rnc
        (Line 58) :

        item = element item {
                attribute id { xsd:ID } ?,
                 (attribute_ | link) *
        }

But I guess I have to move this issue over to the Gtk+ list.

However I wonder if I am really the first one encountering this issue. I mean 
it should be quite common to retrieve menu items at runtime. Or does that mean 
other people are using a different approach by assembling menus with

        <object class="GtkMenuItem" id="foo">

format instead?

CU
Christian