How to set Dashboard to be start page (home page) in the code?

Hi,
Thanks for making Graylog available and free.
I am using Graylog as analyzer for my system (Ubuntu 14.04, Graylog2 - 2.2.1). As we know, when we visit Graylog site (ex: localhost:9000), it will point to Search (or Getting Started if not dismissed). Now I want to make the Dashboard page at home page (Start page), so user will see the dashboard immediately when they visit the site. In dashboard manager page, I can see every dashboard has the button called “Set as start page”, but the button is always disabled! (?). I don’t know the reason.

Then, I tried to download the source project, I ran it successful, but still don’t know where to make the dashboard to be start page (home page).

Hope you can help.

I found it. In the src/pages/StartPage, line 63, this._redirect(Routes.SEARCH), I change it to this._redirect(Routes.DASHBOARDS) and its worked.
Thanks.