Add macro to support mongoid 7

Author: grzegorz-jakubiak

lib/active_admin/mongoid.rb

@@ -13,6 +13,7 @@
 require 'active_admin/mongoid/helpers/collection'
 require 'active_admin/mongoid/criteria'
 require 'active_admin/mongoid/order_clause'
+require 'active_admin/mongoid/association/relatable'
 
 require 'active_admin/mongoid/inputs/filters/check_boxes_input'
 require 'active_admin/mongoid/inputs/filters/select_input'

lib/active_admin/mongoid/association/relatable.rb

@@ -0,0 +1,9 @@
+Mongoid::Association::Relatable.module_eval do
+  def macro
+    self.class.name.split('::').last.underscore.to_sym
+  end
+
+  def embeds?
+    [:embeds_one, :embeds_many].include?(macro)
+  end
+end

lib/active_admin/mongoid/filters/resource_extension.rb

@@ -3,7 +3,7 @@
 module ActiveAdmin::Filters::ResourceExtension
   def default_association_filters
     if resource_class.respond_to?(:reflect_on_all_associations)
-      without_embedded = resource_class.reflect_on_all_associations.reject { |e| [:embeds_many, :embeds_one].include? e.macro }
+      without_embedded = resource_class.reflect_on_all_associations.reject { |e| e.embeds? }
       poly, not_poly = without_embedded.partition{ |r| r.macro == :belongs_to && r.options[:polymorphic] }
 
       filters = poly.map(&:foreign_type) + not_poly.map(&:name)