app/models/city.rb in geopolitical-0.9.3 vs app/models/city.rb in geopolitical-0.9.5

@@ -4,26 +4,37 @@
 class City
   include Mongoid::Document
   include Mongoid::Geospatial
   include Geopolitocracy
 
-  field :area,   type: Integer  # m2 square area
-  field :geom,   type: Point,   spatial: true
+  field :area,    type: Integer  # m2 square area
+  field :geom,    type: Point,   spatial: true
+  # field :capital, type: String
 
   spatial_scope :geom
 
   attr_writer :x, :y, :z
 
   belongs_to :region
   belongs_to :nation
   has_many :hoods
 
+  has_one :nation, as: :capital
+  has_one :region, as: :capital
+
   before_validation :set_defaults, on: [:create]
 
   validates :name, uniqueness: { scope: :region_id }
   validate :region_inside_nation
 
+  scope :population, -> { order_by(souls: -1) }
+
+  index nation_id: 1
+  index souls: -1
+  index name: 1, nation_id: 1
+  index({ region_id: 1 }, sparse: true)
+
   def region_inside_nation
     return if !region || region.nation == nation
     errors.add(:region, 'not inside Nation')
   end
 
@@ -50,13 +61,15 @@
   def postals
     hoods.map(&:postal)
   end
 
   def ==(other)
+    return unless other.is_a?(City)
     other && slug == other.slug
   end
 
   def <=>(other)
+    return unless other.is_a?(City)
     slug <=> other.slug
   end
 
   def with_region
     return name unless region