Ruby on Rails: How to print out a string and where does it display at?

Question

I know this is a trivial question. But I have search all over google but cannot find a simple answer to this question.

Basically I have a line that says <%= link_to 'Run it', :method => 'doIt' %> in the view, then in the corresponding controller, I have the doIt method as follows:

def doIt
  puts "Just do it" 
end

I just want to check that if i click on Run it, it will output the string "Just do it". I ran this on localhost and there is no errors, but I can't find the output "Just do it" anywhere. It is not displayed in the rails console or rails server log. I just want to know where does puts output the string to , where to find it ?

---

Round 2: So this is what I tried ....

Added this line in the index.html.erb (which is the root)

<%= link_to 'Run it', :method => 'do_it' %>

and in the url, it is just basically http://localhost:3000/ (since i route controller#index as root)

The display is just an underlined 'Run it' that links to 'do_it' method in the controller.

In the controller, i include this method

def do_it
  logger.debug "Just do it"
end

when i click on 'Run it', the url change to http://localhost:3000/gollum_starters?method=do_it and in the development.log, the following is written into it:

Started GET "/gollum_starters?method=do_it" for 127.0.0.1 at 2011-08-25 15:27:49 -0700
  Processing by GollumStartersController#index as HTML
  Parameters: {"method"=>"do_it"}
  [1m[35mGollumStarter Load (0.3ms)[0m  SELECT "gollum_starters".* FROM "gollum_starters"
Rendered gollum_starters/index.html.erb within layouts/application (3.6ms)
Completed 200 OK in 16ms (Views: 7.7ms | ActiveRecord: 0.3ms)

Additionally, i tried all the logger.error/info/fatal/etc ... and Rails.logger.error/info/fatal/etc, all did not print out the line "Just do it" in the development log

@Paul: I did not touch the environment folder or file, i assume by default when a new rails app is created, it is in development ?

@Maz: Yes you are right, I am just trying to test if the do_it method is getting called. To do that, I just want to print something out in the controller. Can't think of any way simpler that just print a string out, but this problem is making me miserable. I am just using textmate, no IDE.

---

Round 3:

@Paul thx alot, but i encountered error

My routes files is now:

resources :gollum_starters

root :to => "gollum_starters#index"

match 'gollum_starters/do_it' => 'gollum_starters#do_it', :as => 'do_it'

My index.html.erb is now:

<%= link_to "Do it", do_it_path %>

My gollum_starters_controller.rb

def do_it
  logger.debug 'Just do it'
end

I am getting this error:

Couldn't find GollumStarter with ID=do_it

the error is in here, 2nd line:

def show
    @gollum_starter = GollumStarter.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.xml  { render :xml => @gollum_starter }
    end
  end

I wonder why does it route to show ? When i click do_it, it actually goes to localhost:3000/gollum_starters/do_it which is correct, but apparently the error points to the show method ?

---

Round 4:

@Paul, i shifted resources :gollum_starters down:

root :to => "gollum_starters#index"

match 'gollum_starters/do_it' => 'gollum_starters#do_it', :as => 'do_it'

resources :gollum_starters

but got this error (omg i wanna kill myself),

Template is missing

Missing template gollum_starters/do_it with {:handlers=>[:erb, :rjs, :builder, :rhtml, :rxml], :formats=>[:html], :locale=>[:en, :en]} in view paths "~/project_name/app/views"

:/

---------- Answer to Round 4 ------------

Basically as the error explains, there is no template(i.e a webpage) to show hence error thrown. The solution is to add a redirect_to , in this case I redirect to root_url.

def do_it
  logger.debug 'Just do it'
  redirect_to(root_url)
end

Everything works now, "Just do it" finally outputs to development.log and the rails server console.

Thank you Maz and Paul and Andrew for helping me out. Learn a lot.

Answer 1

That link_to does not do what you think it does the value for :method is referring to the HTTP verbs.

Taken from the docs for ActionView::Helpers::UrlHelper

:method - Symbol of HTTP verb. Supported verbs are :post, :get, :delete and :put. By default it will be :post.

You would need to define a route in your routes.rb file that uses your method

# The order of routes is important as the first matched will be used
# therefore the match needs to be above 'resources :controller'
match 'controller/do_it' => 'controller#do_it', :as => 'do_it'

resources :gollum_starters # <--- This needs to be below the match or this will catch first

• The controller/do_it is the route to be matched
• The controller#do_it is the controller followed by the action to be used (separated by #)
• The value for :as creates the path do_it_path that can be used in your link_to

Your link_to may look something like

<%= link_to "Do it", do_it_path %>

And to complete the lifecycle of a request you will need to add a view to be rendered

 app/views/gollum_startes/do_it.html.erb # <-- Add file 

Summary Doing all of this creates a bit of a mess just to print something out to the logs, but it should help you understand the whole lifecycle a bit better now. Plus this answers serves as a document to help you rewind this mess.