Comments on: Wrapping Conditional Access with with_scope http://codecolossus.com/2008/02/02/wrapping-conditional-access-with-with_scope/ Software Craftsmanship with Ruby Wed, 28 Dec 2011 17:54:32 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: benhughes http://codecolossus.com/2008/02/02/wrapping-conditional-access-with-with_scope/comment-page-1/#comment-10 benhughes Wed, 27 Feb 2008 14:07:14 +0000 http://www.railsgarden.com/2008/02/02/wrapping-conditional-access-with-with_scope/#comment-10 has_many :conditions is not a solution to this problem and I'm not sure you fully understood the problem my post is trying to solve. In my original code, forcing the requirement of active = 1 on ALL queries involving Entry within the controller is completely handled by the around filter and with_scope in a most AOP manner. I'm not looking for a elegant way of getting active only entries as such a solution would require explicitly saying "something.entries.active". The above is completely transparent to the rest of the controller except of course if you are manually invoking find_by_conditions. But you raise a point about with_scope being protected. Just as easily I could have defined a method in entry that handled this: <pre name="code" class="ruby"> def self.scope_to_active self.send(:with_scope, :find => {:conditions => 'active = 1'}) do yield end end </pre> .. and then called it from the controller. This is probably a better solution. If you want to use this with multiple models you could even create a module and mix it in since the above code is generic so long as the model has an "active" attribute. You can then nest-scope multiple of these. has_many :conditions is not a solution to this problem and I’m not sure you fully understood the problem my post is trying to solve. In my original code, forcing the requirement of active = 1 on ALL queries involving Entry within the controller is completely handled by the around filter and with_scope in a most AOP manner. I’m not looking for a elegant way of getting active only entries as such a solution would require explicitly saying “something.entries.active”. The above is completely transparent to the rest of the controller except of course if you are manually invoking find_by_conditions.

But you raise a point about with_scope being protected. Just as easily I could have defined a method in entry that handled this:

def self.scope_to_active
  self.send(:with_scope, :find => {:conditions => 'active = 1'}) do
    yield
  end
end

.. and then called it from the controller. This is probably a better solution. If you want to use this with multiple models you could even create a module and mix it in since the above code is generic so long as the model has an “active” attribute. You can then nest-scope multiple of these.

]]> By: Neil Wilson http://codecolossus.com/2008/02/02/wrapping-conditional-access-with-with_scope/comment-page-1/#comment-9 Neil Wilson Wed, 27 Feb 2008 11:43:15 +0000 http://www.railsgarden.com/2008/02/02/wrapping-conditional-access-with-with_scope/#comment-9 with_scope is protected for a reason - people abuse it instead of creating associations properly using the modelling tools. It is a 'code smell' that suggests you are using a Rails anti-patterns. "has_many :conditions" is your friend, or perhaps something like this: http://weblog.jamisbuck.org/2007/1/9/extending-activerecord-associations Try it between the User and Entry models and see what you come up with. with_scope is protected for a reason – people abuse it instead of creating associations properly using the modelling tools. It is a ‘code smell’ that suggests you are using a Rails anti-patterns.

“has_many :conditions” is your friend, or perhaps something like this:

http://weblog.jamisbuck.org/2007/1/9/extending-activerecord-associations

Try it between the User and Entry models and see what you come up with.

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