# How to include a module in a model **URL:** \ **Category:** Rails\ **Created:** [August 23, 2010, 9:14pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743 "2010-08-23T21:14:09Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [August 23, 2010, 9:14pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/1 "2010-08-23T21:14:09Z")
I created a module MyModule “my\_module.rb” and put in a lib folder in my rails app. In my User.rb model I call include MyModule. When I try to use a method inside MyModule I get an “undefined method error”. How do I include this module in the model? Thanks ---
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [August 23, 2010, 9:15pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/2 "2010-08-23T21:15:46Z")
badnaam wrote: > I created a module MyModule “my\_module.rb” and put in a lib folder in > my rails app. > > In my User.rb model I call include MyModule. > > When I try to use a method inside MyModule I get an “undefined method > error”. How do I include this module in the model? What you described should work. Let’s see code. > Thanks Best, –Â Marnen Laibow-Koser [http://www.marnen.org](http://www.marnen.org) removed\_email\_address@domain.invalid Sent from my iPhone ---
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [August 23, 2010, 9:23pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/3 "2010-08-23T21:23:31Z")
[http://pastie.org/1110631](http://pastie.org/1110631) ---
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [August 23, 2010, 9:45pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/4 "2010-08-23T21:45:47Z")
I suspect that after you require validation\_group.rb you want to have something like: ActiveRecord::Base.class\_eval { extend ValidationGroup::ActiveRecord::ActsMethod } You need to get the “validation\_group” method into ActiveRecord::Base and therefore User before you call it. -Rob On Aug 23, 2010, at 3:22 PM, badnaam wrote: > > > When I try to use a method inside MyModule I get an "undefined > > > – > > > Groups “Ruby on Rails: Talk” group. > > > To post to this group, send email to rubyonrails- > > > removed\_email\_address@domain.invalid. > > > To unsubscribe from this group, send email to removed\_email\_address@domain.invalid > > > . > > > For more options, visit this group at [http://groups.google.com/group/rubyonrails-talk?hl=en](http://groups.google.com/group/rubyonrails-talk?hl=en) > > > . Rob B. removed\_email\_address@domain.invalid [http://AgileConsultingLLC.com/](http://AgileConsultingLLC.com/) removed\_email\_address@domain.invalid [http://GaslightSoftware.com/](http://GaslightSoftware.com/) ---
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [August 23, 2010, 9:22pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/5 "2010-08-23T21:22:56Z")
Here is the code… [http://pastie.org/1110631](http://pastie.org/1110631) Thanks ---
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [August 23, 2010, 9:51pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/6 "2010-08-23T21:51:38Z")
Rob, Are you saying I need to do a 1 - require ‘validation\_group’ in my User.rb 2 - Then add ActiveRecord::Base.class\_eval { extend ValidationGroup::ActiveRecord::ActsMethod } to my User.rb? Thanks On Aug 23, 12:44 pm, Rob B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [August 23, 2010, 9:59pm UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/7 "2010-08-23T21:59:15Z")
On Aug 23, 2010, at 3:50 PM, badnaam wrote: > > > > ActiveRecord::Base.class\_eval { extend > ValidationGroup::ActiveRecord::ActsMethod } > to my User.rb? > > Thanks No, I don’t know what you “need” only what I “suspect” your code is missing. Probably not in your user.rb, but in an initializer somewhere. (config/initializers/validation\_group.rb or in config/ environment.rb) If you’re modifying the plugin, you really need to understand the Ruby hook methods (like extended() and included()) or at least copy all the relevant bits when you’re cargo-culting a solution. -Rob > > > > > I created a module MyModule “my\_module.rb” and put in a lib > > > > > > Posted viahttp://www.ruby-forum.com/. > > . > For more options, visit this group at [http://groups.google.com/group/rubyonrails-talk?hl=en](http://groups.google.com/group/rubyonrails-talk?hl=en) > . Rob B. removed\_email\_address@domain.invalid [http://AgileConsultingLLC.com/](http://AgileConsultingLLC.com/) removed\_email\_address@domain.invalid [http://GaslightSoftware.com/](http://GaslightSoftware.com/) ---
**Author:** ![badnaam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e36b37/32.png) [@badnaam](https://www.ruby-forum.com/u/badnaam)\ **Post date:** [September 2, 2010, 8:42am UTC](https://www.ruby-forum.com/t/how-to-include-a-module-in-a-model/193743/8 "2010-09-02T08:42:28Z")
ouch. Cargo cult. a bit harsh. At some point we were all learning to program. How we treat the newcomer says a lot about the Rails community. badnamm, I think what you’re trying to do might be satisfied by extend not include. see this article for more info. [http://railstips.org/blog/archives/2009/05/15/include-vs-extend-in-ruby/](http://railstips.org/blog/archives/2009/05/15/include-vs-extend-in-ruby/) dave On Aug 23, 12:58 pm, Rob B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)