Add ability to use nested only parameter

- The only string works much the same as before with its comma separation
-- Nested includes are indicated with square brackets "[ ]"
-- The nested include is the value immediately preceding the square brackets
-- The only string is the comma separated string inside those brackets
- Default includes are split between format types when necessary
-- This prevents unnecessary includes from being added on page load
- Available includes are those items which are allowed to be accessible to the user
-- Some aren't because they are sensitive, such as the creator of a flag
-- Some aren't because the number of associated items is too large
- The amount of times the same model can be included to prevent recursions
-- One exception is the root model may include the same model once
--- e.g. the user model can include the inviter which is also the user model
-- Another exception is if the include is a has_many association
--- e.g. artist urls can include the artist, and then artist urls again

app/controllers/ip_addresses_controller.rb

@@ -3,16 +3,30 @@ class IpAddressesController < ApplicationController
   before_action :moderator_only
 
   def index
-    @ip_addresses = IpAddress.visible(CurrentUser.user).paginated_search(params)
+    @ip_addresses = IpAddress.visible(CurrentUser.user).paginated_search(params).includes(model_includes(params))
 
     if search_params[:group_by] == "ip_addr"
       @ip_addresses = @ip_addresses.group_by_ip_addr(search_params[:ipv4_masklen], search_params[:ipv6_masklen])
     elsif search_params[:group_by] == "user"
-      @ip_addresses = @ip_addresses.group_by_user.includes(:user)
-    else
-      @ip_addresses = @ip_addresses.includes(:user, :model)
+      @ip_addresses = @ip_addresses.group_by_user
     end
 
     respond_with(@ip_addresses)
   end
+
+  private
+
+  def default_includes(params)
+    if ["json", "xml"].include?(params[:format])
+      []
+    else
+      if params[:search][:group_by] == "user"
+        [:user]
+      elsif params[:search][:group_by] == "ip_addr"
+        []
+      else
+        [:user, :model]
+      end
+    end
+  end
 end