# Using application\_helper.rb **URL:** \ **Category:** Rails\ **Created:** [June 26, 2006, 7:55am UTC](https://www.ruby-forum.com/t/using-application-helper-rb/64477 "2006-06-26T07:55:03Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![craigrails](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/c2a13f/32.png) [@craigrails](https://www.ruby-forum.com/u/craigrails)\ **Post date:** [June 26, 2006, 7:55am UTC](https://www.ruby-forum.com/t/using-application-helper-rb/64477/1 "2006-06-26T07:55:03Z")
I have a simple Yes/No selection list that I am using in a number of places. Thinking that I could DRY things out a bit, I added it to application\_helper.rb … YES\_NO = [ [“Yes”, true], [“No”, false] ].freeze So I figured I would use it there instead of in each model.rb where needed. anyway, in webrick screen, I am continually seeing this… script/…/config/…/app/helpers/application\_helper.rb:6: warning: already initialized constant YES\_NO Am I doing something wrong? Is there a better way to do this? Craig ---
**Author:** ![craigrails](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/c2a13f/32.png) [@craigrails](https://www.ruby-forum.com/u/craigrails)\ **Post date:** [June 26, 2006, 9:00am UTC](https://www.ruby-forum.com/t/using-application-helper-rb/64477/2 "2006-06-26T09:00:50Z")
On Jun 26, 2006, at 12:51 AM, Craig W. wrote: > needed. > > * * * > > Rails mailing list > removed\_email\_address@domain.invalid > [http://lists.rubyonrails.org/mailman/listinfo/rails](http://lists.rubyonrails.org/mailman/listinfo/rails) YES\_NO = [ [“Yes”, true], [“No”, false] ].freeze unless defined? YES\_NO -Ezra ---
**Author:** ![craigrails](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/c2a13f/32.png) [@craigrails](https://www.ruby-forum.com/u/craigrails)\ **Post date:** [June 26, 2006, 4:37pm UTC](https://www.ruby-forum.com/t/using-application-helper-rb/64477/3 "2006-06-26T16:37:05Z")
On 6/26/06, Ezra Z. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > YES\_NO = [ > [“Yes”, true], > [“No”, false] > ].freeze unless defined? YES\_NO > > -Ezra So, isn’t this just saying "only freeze if the object isn’t defined? In which case, it will never be frozen…since its always going to be defined? I think the original code was meant to make a “real” constant, tho I doubt if thats really possible in ruby. - rob ---
**Author:** ![craigrails](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/c2a13f/32.png) [@craigrails](https://www.ruby-forum.com/u/craigrails)\ **Post date:** [June 26, 2006, 4:49pm UTC](https://www.ruby-forum.com/t/using-application-helper-rb/64477/4 "2006-06-26T16:49:37Z")
I think that the code that Ezra put forward will declare and then freeze unless defined. Both actions will occur or neither will. One thing I don’t understand about this snippet is why would YES\_NO be defined? I thought that each request is a request all of it’s own. Share nothing. Doesn’t this mean that it will only be defined when the application\_helper.rb is initally loaded? Since I don’t think it’s loaded more than once I don’t understand the point of the unless defined? is. ---
**Author:** ![craigrails](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/c2a13f/32.png) [@craigrails](https://www.ruby-forum.com/u/craigrails)\ **Post date:** [June 26, 2006, 5:16pm UTC](https://www.ruby-forum.com/t/using-application-helper-rb/64477/5 "2006-06-26T17:16:08Z")
For one thing, the unless defined? YES\_NO addition quieted the display - which was the result I was looking for. I guess that application\_helper.rb is continually reloaded in development mode (which is the current environment for this section of code) but in production, I would guess that it is only loaded once and it wouldn’t have mattered. If that is the case, I probably could have just ignored the on-screen noise but I try to quiet noise where I can. Craig ---
**Author:** ![craigrails](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/c2a13f/32.png) [@craigrails](https://www.ruby-forum.com/u/craigrails)\ **Post date:** [June 27, 2006, 5:31am UTC](https://www.ruby-forum.com/t/using-application-helper-rb/64477/6 "2006-06-27T05:31:11Z")
On Mon, Jun 26, 2006 at 09:35:02AM -0500, Rob S. wrote: > On 6/26/06, Ezra Z. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > YES\_NO = [ > > [“Yes”, true], > > [“No”, false] > > ].freeze unless defined? YES\_NO > So, isn’t this just saying "only freeze if the object isn’t defined? No, it’s saying “define YES\_NO and freeze it unless it exists” (YES\_NO = […].freeze) unless … ## Saludos! HoraPe Horacio J. Peñremoved\_email\_address@domain.invalid removed\_email\_address@domain.invalid