Scope Out Rails

Usage

1 class Thing < ActiveRecord::Base
2     scope_out :active, :field => 'active', :value => true
3     # in this case :field can be omitted since it matches the scope name 'active'
4   end
The above code creates three class methods: find_active, with_active, and calculate_active. It is equivalent to doing the following: 
 1 class Thing < ActiveRecord::Base
 2     def Thing.with_active
 3       with_scope :find => {:conditions => ['active => ?', true]} do
 4         yield
 5       end
 6     end
 7 
 8     def Thing.find_active(*args)
 9       with_active {find(*args)}
10     end
11 
12     def Thing.calculate_active(*args)
13       with_active {calculate(*args)}
14     end
15   end

with_x

Thing.with_active acts just like with_scope, except the scope is already defined.

For example: 
1 Thing.with_active do
2     Thing.find(:all, :order => 'stuff desc')
3   end

find_x

Thing.find_active acts just like find, except that it is scoped with with_active: 
1 Thing.find_active(:first, :include => :other_stuff)

is equivalent to

1 Thing.find(:first, :conditions => ['active = ?', true], :include => :other_stuff)

calculate_x

Thing.calculate_active (you guessed it) is exactly like Thing.calculate, but scoped with ‘with_active’ 
1 Thing.calculate_active(:count, :all)
is equivalent to 
1 Thing.calculate(:count, :all, :conditions => ['active = ?', true])

Alternate Syntax

In addition, an alternate and more flexible syntax accepts the :conditions argument and passes it on to the scope methods. It will accept any form of the conditions argument that is valid for ActiveRecord::Base#find

1 class Stuff < ActiveRecord::Base
2     scope_out :teenagers, :conditions => 'age between 13 and 19'
3   end
4 
5   Stuff.find_teenagers(:all)

Tags

Currently tagged with: activerecord, finders
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