# Activerecord re-sets class members to null? **URL:** \ **Category:** Rails\ **Created:** [August 16, 2010, 4:48pm UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362 "2010-08-16T16:48:59Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![techy\_bolek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ee59a6/32.png) [@techy\_bolek](https://www.ruby-forum.com/u/techy_bolek)\ **Post date:** [August 16, 2010, 4:48pm UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362/1 "2010-08-16T16:48:59Z")
I have two classes with class variables. One of them derives from active record, the other one does not. I initialize both members to NULL, then lazy-instantiate them. The class which does not derive from active record preserves the value correctly. The class which does derive from active record always seems to be re-setting it to NULL. class Class1 ## @@thelist holds the initialized value @@thelist = nil attr\_accessor :name, :id def self.retrieveall if @@thelist.nil? @@thelist = Array.new ``` entry = Locale.new entry.id = "en" entry.name = "english" @@thelist << entry //repeat to populate end @@thelist ``` end end class Class2 \< ActiveRecord::Base ## anytime retrieveall is called @@thelist is always NULL. Why? @@thelist = nil attr\_accessor :name, :id def self.retrieveall if @@thelist.nil? @@thelist = Class2.all end ``` @@thelist ``` end end ---
**Author:** ![techy\_bolek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ee59a6/32.png) [@techy\_bolek](https://www.ruby-forum.com/u/techy_bolek)\ **Post date:** [August 16, 2010, 5:25pm UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362/2 "2010-08-16T17:25:42Z")
On Aug 16, 3:48 pm, Tomasz R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > I have two classes with class variables. One of them derives from active > record, the other one does not. I initialize both members to NULL, then > lazy-instantiate them. The class which does not derive from active > record preserves the value correctly. The class which does derive from > active record always seems to be re-setting it to NULL. Most classes in your app are reloaded between requests. Is this the problem ? Fred ---
**Author:** ![techy\_bolek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ee59a6/32.png) [@techy\_bolek](https://www.ruby-forum.com/u/techy_bolek)\ **Post date:** [August 16, 2010, 5:29pm UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362/3 "2010-08-16T17:29:48Z")
On Aug 16, 4:23 pm, Frederick C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > On Aug 16, 3:48 pm, Tomasz R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > I have two classes with class variables. One of them derives from active > > record, the other one does not. I initialize both members to NULL, then > > lazy-instantiate them. The class which does not derive from active > > record preserves the value correctly. The class which does derive from > > active record always seems to be re-setting it to NULL. > > Most classes in your app are reloaded between requests. Is this the > problem ? To clarify, that of course only happens in development Fred ---
**Author:** ![techy\_bolek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ee59a6/32.png) [@techy\_bolek](https://www.ruby-forum.com/u/techy_bolek)\ **Post date:** [August 17, 2010, 2:10am UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362/4 "2010-08-17T02:10:51Z")
> > Most classes in your app are reloaded between requests. Is this the > > problem ? > > To clarify, that of course only happens in development Yep, that’s it, thanks. Makes me wonder how I can control which classes should be reloaded. I’m trying to make something off of development.rb and production.rb. ---
**Author:** ![techy\_bolek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ee59a6/32.png) [@techy\_bolek](https://www.ruby-forum.com/u/techy_bolek)\ **Post date:** [August 17, 2010, 4:50am UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362/5 "2010-08-17T04:50:10Z")
On Mon, Aug 16, 2010 at 7:10 PM, Tomasz R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Yep, that’s it, thanks. Makes me wonder how I can control which classes > should be reloaded. I’m trying to make something off of development.rb > and production.rb. Rails comes with 3 development environments already ready to go, look database.yml. In development and testing, all classes are always reloaded. In production they are always cached. How is this not exactly what you want? 🙂 – Greg D. [destiney.com](http://destiney.com) | [gregdonald.com](http://gregdonald.com) ---
**Author:** ![techy\_bolek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ee59a6/32.png) [@techy\_bolek](https://www.ruby-forum.com/u/techy_bolek)\ **Post date:** [August 18, 2010, 1:57am UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362/6 "2010-08-18T01:57:16Z")
On Aug 18, 12:33 am, Tomasz R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > Rails comes with 3 development environments already ready to go, look > > database.yml. In development and testing, all classes are always > > reloaded. > > This does not seem to be true. In my example above, if a class does not > derive from ActiveRecord::Base it preserves its class attributes between > requests, a plausible explanation being that it’s NOT in fact reloaded. Deriving from activerecord or not should have no incidence. How the particular class is loaded can influence reloading, the only thing that you’re likely to do by accident is requiring a file explicitly Fred ---
**Author:** ![techy\_bolek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/ee59a6/32.png) [@techy\_bolek](https://www.ruby-forum.com/u/techy_bolek)\ **Post date:** [August 18, 2010, 1:33am UTC](https://www.ruby-forum.com/t/activerecord-re-sets-class-members-to-null/193362/7 "2010-08-18T01:33:53Z")
> Rails comes with 3 development environments already ready to go, look > database.yml. In development and testing, all classes are always > reloaded. This does not seem to be true. In my example above, if a class does not derive from ActiveRecord::Base it preserves its class attributes between requests, a plausible explanation being that it’s NOT in fact reloaded. > In production they are always cached. How is this not > exactly what you want? 🙂 > Very simple. I only would like to be reloading the classes that I’m > currently messing with. Reloading all the classes is a waste of time.