I am currently writing a plugin and I struggle with specifying the default submenu.
I have used the $order parameter in Piwik_AddMenu which allowed me to order the submenus the way I want, but I can’t for the life of me figure out how to specify the submenu that will get selected if I click on the top menu.
In my case it’s the 4th submenu which is selected by default.
Note though, that I’m still on Piwik1.2. I don’t know if this is a bug that has been fixed in newer versions?
Unfortunately, our Piwik installation has undergone too many changes to allow for an upgrade.