How to create a model scope with Geocoder? - ruby-on-rails

Question

I have the following models, User, Dad, Mom, Follow and Kid.
class User
has_many :kids
has_many :follows
geocoded_by :address
end
class Dad
has_many :kids
has_many :follows
end
class Mom
has_many :kids
geocoded_by :address
end
class Follow
belongs_to :dad
end
class Kid
belongs_to :mom
belongs_to :dad
belongs_to :user
end
With the Geocoder gem I'm trying to create a scope that takes in the total count of the Dad's Kids nearest to the User's location compared to the Kids Mom's locations that happened today.
<% #follows.each do |f| %>
<% f.dad.kids.today.nearest.count
<% end %>
In my ApplicationController:
def set_user_location
if signed_in?
#user_location = current_user.address
end
end
In my Kid model:
scope :today, -> { where("kids.created_at > ?", Time.now.beginning_of_day) }
scope :nearest, -> { joins(:mom).merge(Mom.near(#user_location, 2000)) }
But the nearest doesn't work. It doesn't load Moms at all.
User Load (0.6ms) SELECT "users".* FROM "users" WHERE "users"."id" = 5 ORDER BY "users"."id" ASC LIMIT 1
Processing by FollowsController#index as HTML
Follow Exists (0.3ms) SELECT 1 AS one FROM "follows" WHERE "follows"."user_id" = $1 LIMIT 1 [["user_id", 5]]
Follow Load (0.5ms) SELECT "follows".* FROM "follows" INNER JOIN "dads" ON "dads"."id" = "follows"."dad_id" WHERE "follows"."user_id" = $1 ORDER BY name ASC LIMIT 30 OFFSET 0 [["user_id", 5]]
Product Load (0.2ms) SELECT "dads".* FROM "dads" WHERE "dads"."id" = $1 ORDER BY "dads"."id" ASC LIMIT 1 [["id", 39]]
(0.7ms) SELECT COUNT(*) FROM "kids" WHERE "kids"."dad_id" = $1 AND (kids.created_at > '2014-05-08 04:00:00.000000') [["dad_id", 39]]
CACHE (0.0ms) SELECT COUNT(*) FROM "kids" WHERE "kids"."dad_id" = $1 AND (kids.created_at > '2014-05-08 04:00:00.000000') [["dad_id", 39]]
What would be the correct way to write the nearest scope?

Answer 1

Problem is with today scope, not nearest.
Every model has sreated_at field so in your scope you should write
scope :today, -> { where("kids.created_at > ?", Time.now.beginning_of_day) }
EDIT:
Another error is that you're referring to controller instance variable in model. Model and controller are separated so it will not work this way. Instead you should rewrite scope to
scope :nearest, ->(location, distance=2000) { joins(:mom).merge(Mom.near(location, distance)) }
and then in the controller you may write
Kid.nearest(some location goes here)
but I think your models are a little messed up and you want them to do something different.
WhatI suppose you want to do is find a mother that is nearest to kid, so rather you should do something like
Mom.near(some_kid, 2000)