#263 calling named scope in class method - Ruby on Rails

Type	To find
responsible:me	tickets assigned to you
tagged:"@high"	tickets tagged @high
milestone:next	tickets in the upcoming milestone
state:invalid	tickets with the state invalid
created:"last week"	tickets created last week
sort:number, importance, updated	tickets sorted by #, importance or updated
Combine keywords for powerful searching.
Use advanced searching »

This project is archived and is in readonly mode.

#263 ✓invalid

calling named scope in class method

Reported by Ryan Bates | May 27th, 2008 @ 04:21 PM

When a named scope is called inside a class method, it loses the other scopes in the chain. For example:

class Topic < ActiveRecord::Base
  named_scope :approved, :conditions => {:approved => true}
  named_scope :replied, :conditions => ['replies_count > 0']

  def self.approved_through_class_method
    approved
  end
end

Topic.replied.approved_through_class_method # => loses replied scope

What's interesting is that if I append "all" to the approved call in the class method then it will work.

def self.approved_through_class_method
  approved.all
end

Topic.replied.approved_through_class_method # => keeps replied scope

I have attached a failing test, but I'm not familiar enough with named_scope to make it pass.

Comments and changes to this ticket

josh July 17th, 2008 @ 01:59 AM
- Assigned user set to “Pratik”
- Tag set to “bug, named_scope, tested”
Pratik July 18th, 2008 @ 03:02 AM
- State changed from “new” to “invalid”
This would happen because you're calling approved_through_class_method on Scope object. In case of Topic.replied.approved, Scope#method_missing checks @@scopes hash to see if :approved is a named scope or not. Wherein case of Topic.replied.approved_through_class_method, there is no way to determine if approved_through_class_method is going to return a named scope or not.
The real solution to this would be very fugly and in no way not worth it.
So the practical solution : Define the method in named scope extension.
```
  named_scope :replied, :conditions => ['replies_count > 0'] do
    def approved_through_class_method
      approved
    end
  end
```