silverstripe - How to add custom item to left CMS menu and manage model and extra fields? Similar to ModelAdmin? -

is possible have model admin type setup, there tab on left menu e.g staff members, , on right instead of displaying grid , managing model, want have fields sit above grid , able save data them...

essentially working same how on page, instead in own tab on sidebar etc?

picture of trying achieve (photoshopped)

is possible?

yes can. you'll have create own subclass of leftandmain , implement form overriding geteditform.

say named new leftandmain subclass staffadmin, can add cms menu adding _config.php file:

cmsmenu::add_menu_item('staffadmin', 'staff admin', 'staffadmin', 'staffadmin');