Ruby on Rails

Hi,

I have the below resource table Comment controller :

[arup@app]$ rake routes | grep comments
      comments    GET    /comments(.:format)          comments#index
                           POST   /comments(.:format)          comments#create
   new_comment  GET    /comments/new(.:format)      comments#new
  edit_comment   GET    /comments/:id/edit(.:format) comments#edit
       comment     GET    /comments/:id(.:format)      comments#show
                           PATCH  /comments/:id(.:format)      comments#update
                           PUT    /comments/:id(.:format)      comments#update
                           DELETE /comments/:id(.:format)      comments#destroy

Now, I am trying to figure out what I read from the guide - http://guides.rubyonrails.org/v4.1.8/routing.html#creating-paths-and-urls-from-objects

=======
If you wanted to link to just a magazine:....
For other actions, you just need to insert the action name as the first element of the array:...
=======

I tried -

helper.link_to("Show comment", [Comment.first], method: :get)
helper.link_to("Show comment", Comment.first, method: :get)
helper.link_to("Show comment", [:show, Comment.first])
helper.link_to("Show comment", Comment.first, method: :get)

Always I'm getting the error as : ArgumentError: arguments passed to url_for can't be handled. Please require routes or provide your own implementation

Any idea what am I doing wrong ? I am not getting the result as guide promised. :-)

--
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Regards,
Arup Rakshit
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Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.

--Brian Kernighan