Re: [Vala] static string variable is empty!

[Frederik <scumm_fredo gmx net>]

golnaz nilieh wrote:
> Hello everybody!
> I'm a newbie to vala language, I faced to a strange problem recently and
> couldn't find any help in vala documentations.
> In my app, I have declared a class named "Global" in a file "global.vala":
>
> using GLib;
> public class MyApp.Global : GLib.Object {
>     public static string dataDir = "/usr/local/share/";
> }
>
> And I have a "main.vala" file, whith this code inside:
>
> using GLib;
> using Gtk;
> public class MyApp.MainWindow : Window {
>    static int main (string[] args) {
>       stdout.printf ("all data is in: " + Global.dataDir);
>       return 0;
>    }
> }
>
> After compilation, I get this string in terminal:
> all data is in:
>
> Seems that Global.dataDir is empty. Where is my mistake?
> Thanks.

Non-value-type static class variables are only initialized after the
class was instantiated at least once. This behaviour is a little bit
counter-intuitive, and I hope it will change in the future.

You have several options:

- create a throw-away instance:

  static int main (string[] args) {
      new Global ();
      stdout.printf ("all data is in: " + Global.dataDir);
      return 0;
  }

- call a static initialization method:

  static int main (string[] args) {
      Global.init ();
      stdout.printf ("all data is in: " + Global.dataDir);
      return 0;
  }

- make 'dataDir' const, if it is not intended to change


Best regards,

Frederik