# Meta programming problem **URL:** \ **Category:** rubyonrails-talk\ **Created:** [December 4, 2006, 10:33pm UTC](https://discuss.rubyonrails.org/t/meta-programming-problem/5450 "2006-12-04T22:33:50Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Dj\_T](https://avatars.discourse-cdn.com/v4/letter/d/ecccb3/32.png) [@Dj\_T](https://discuss.rubyonrails.org/u/Dj_T)\ **Post date:** [December 4, 2006, 10:33pm UTC](https://discuss.rubyonrails.org/t/meta-programming-problem/5450/1 "2006-12-04T22:33:50Z")
Hi, i've wrote the following code module TeamScore   class Filter     ALLOWED\_RESOURCES = [:game]     # convert \ into markdown link to game re     # use game title as link name     # "Google":[http://google.com](http://google.com). ---
**Author:** ![Max\_Muermann](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@Max\_Muermann](https://discuss.rubyonrails.org/u/Max_Muermann)\ **Post date:** [December 5, 2006, 1:25am UTC](https://discuss.rubyonrails.org/t/meta-programming-problem/5450/2 "2006-12-05T01:25:14Z")
> Hi, > > i've wrote the following code module TeamScore   class Filter     ALLOWED\_RESOURCES = [:game] > >     # convert \ into markdown link to game re     # use game title as link name     # "Google":[http://google.com](http://google.com).     #     def self.filter(str)       str.gsub(/\<([a-z]+):(\d+)\>/) do |match|         create\_link\_for($1.to\_sym,$2, match)       end     end > >     def self.create\_link\_for(resource\_type, id, match)       raise "Macro #{match} not allowed" unless ALLOWED\_RESOURCES.include?(resource\_type.to\_sym)       case resource\_type         when :game           model = Game         when :article           model = Article       end       object = model.send("find", id) > > "\"#{object.name}\":www.teamscore.org/#{object.class.name.pluralize.downcase}/#{object.id}"     end   end end > > How i can dry case when block. Remove it altogether 😉 see below. > My idea is to send a find message to model coresponding the resource\_type argument but resource\_type is a string (previously extracted from regexp) and I can't use ressource\_type.send(....) or send("#{ressource\_type.classify}.find", id) the 2 stament raise an error (NoMethodError: undefined method `Game' for TeamScore::Filter:Class) You don't need the send here. Send without an object tries to execute send on the current scope, which would be TeamScore::Filter. In this case, you are trying to execute self.Game.find(id), which is of course not valid (unless you happened to have a constant called Game defined on the class...). Try resource\_type.classify.find(id). resource\_type.classify will simply return the class (Game or Article), which you can happily call any methods on. Cheers, Max ---
**Author:** ![Dj\_T](https://avatars.discourse-cdn.com/v4/letter/d/ecccb3/32.png) [@Dj\_T](https://discuss.rubyonrails.org/u/Dj_T)\ **Post date:** [December 5, 2006, 8:03am UTC](https://discuss.rubyonrails.org/t/meta-programming-problem/5450/3 "2006-12-05T08:03:52Z")
Max Muermann a écrit : > Remove it altogether 😉 see below. > > \> My idea is to send a find message to model coresponding the \> resource\_type argument but resource\_type is a string (previously \> extracted from regexp) and I can't use ressource\_type.send(....) \> or send("#{ressource\_type.classify}.find", id) the 2 stament raise an \> error (NoMethodError: undefined method `Game' for \> TeamScore::Filter:Class) > > You don't need the send here. Send without an object tries to execute send on the current scope, which would be TeamScore::Filter. In this case, you are trying to execute self.Game.find(id), which is of course not valid (unless you happened to have a constant called Game defined on the class...). > > Try resource\_type.classify.find(id). > > resource\_type.classify will simply return the class (Game or Article), which you can happily call any methods on. > > Cheers, Max Thanks, I've try it but this doesn't work. I've got an LocalJumpError or something like this. I think it try to invoke find on a String not on the Game or Article. The classify method just retunr a string in my mind. ---
**Author:** ![Jean-Francois1](https://avatars.discourse-cdn.com/v4/letter/j/a5b964/32.png) [@Jean-Francois1](https://discuss.rubyonrails.org/u/Jean-Francois1)\ **Post date:** [December 5, 2006, 9:56am UTC](https://discuss.rubyonrails.org/t/meta-programming-problem/5450/4 "2006-12-05T09:56:23Z")
Guillaume : > \> You don't need the send here. Send without an object tries to execute \> send on the current scope, which would be TeamScore::Filter. In this \> case, you are trying to execute self.Game.find(id), which is of course \> not valid (unless you happened to have a constant called Game defined \> on the class...). \> \> Try resource\_type.classify.find(id). \> \> resource\_type.classify will simply return the class (Game or Article), \> which you can happily call any methods on. > > Thanks, > > I've try it but this doesn't work. I've got an LocalJumpError or something like this. I think it try to invoke find on a String not on the Game or Article. The classify method just retunr a string in my mind. Try :   resource\_type.classify.constantize.find(id)     -- Jean-François. ---
**Author:** ![Dj\_T](https://avatars.discourse-cdn.com/v4/letter/d/ecccb3/32.png) [@Dj\_T](https://discuss.rubyonrails.org/u/Dj_T)\ **Post date:** [December 5, 2006, 7:02pm UTC](https://discuss.rubyonrails.org/t/meta-programming-problem/5450/5 "2006-12-05T19:02:25Z")
This work great. Thank a lot. Jean-François a écrit :