I have been trying to find a way to add a class or an id to my custom administration sub menu. I only see a class on the first menu item. I would either like to add a css class or an ID on my sub menu list items.
So I found a solution to my problem. I just added a
span tag in the add_submenu_page() hook and it work:
add_submenu_page( # The slug for the parent menu page to which this sub menu belongs 'email-service', # The text that't rendered in the browser title bar 'Breaking News Email', # The text to be rendered in the menu '<span class="breaking-news-toggle">Breaking News Email</span>', # the capability required to access this menu item 'send_email', # The slug by which this sub menu is identified 'my-email-service', # the function used to display the options for this menu's page array(&$this, 'email_service_form') );