[SOLVED] Scope in where clause

Scope in where clause

You can see the last lines of these two models use the same code:

class Position < ActiveRecord::Base
  scope :last_day, 
  where('positions.created_at > ? AND positions.hidden = ?',
  DateTime.now.in_time_zone("Sofia").yesterday.beginning_of_day + 10.hours, false)
end

class Subscriber < ActiveRecord::Base
  scope :notify_today,
  joins(:tags => :positions).
  where('positions.created_at > subscribers.created_at 
  AND positions.created_at > ? AND positions.hidden = ?', 
  DateTime.now.in_time_zone("Sofia").yesterday.beginning_of_day + 10.hours, false)
end

Is it possible to reuse the 'last_day' scope somehow in the second model?

Solution

where() and joins() both return ActiveRecord::Relation objects, and they have a method called merge() which can merge other ActiveRecord::Relation objects. Therefore, you can simply do this

scope :notify_today, joins(:tags => :positions).merge(Position.last_day)

NOTE: In Rails 3 and lower, & was an alias to merge(). There you were also able to do this

scope :notify_today, joins(:tags => :positions) & Position.last_day