Where should I hook into the admin backend to check and see if the user is "active" as defined by the Membership Plugin.
Or in other words, where can I hook into the WP admin header to check an if-statement and redirect if it fails?
Not sure about the Membership plug-in bit, but admin_init
will be your best bet. I assume that you don't actually what to hook into the admin header though - this would be admin_head
or admin_head-(plugin_page)
- but you cannot redirect after these hooks (headers already sent).