How to add instance methods for the dashboard

The default dashboard has this example in the code comments:

# == Conditionally Display
# Provide a method name or Proc object to conditionally render a section at run time.
#
# section "Membership Summary", :if => :memberships_enabled?

but where do you define :memberships_enabled??

You can't get access to the dashboard controller by doing:

ActiveAdmin::Dashboards.build do
  controller do
    def memberships_enabled?
      true
    end
  end
end

because Dashboard doesn't inherit from DSL like pages and resources do.

This doesn't work either:

ActiveAdmin::Dashboards.build do
  def memberships_enabled?
    true
  end

  section "Membership Summary", :if => :memberships_enabled?
end

Instead, you have to add the method to the dashboard controller directly:

class Admin::DashboardController
  def memberships_enabled?
    true
  end
end

where Admin is your namespace. Note: You may encounter errors about the namespace being undefined. In that case, you may want to defined your helper methods directly on the base dashboard controller class, ActiveAdmin::Dashboards::DashboardController.