How can I call controller/view helper methods from the console in Ruby on Rails?

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When I load script/console, sometimes I want to play with the output of a controller or a view helper method.

Are there ways to:

  • simulate a request?
  • call methods from a controller instance on said request?
  • test helper methods, either via said controller instance or another way?
14 Answers

To call helpers, use the helper object:

$ ./script/console
>> helper.number_to_currency('123.45')
=> "R$ 123,45"

If you want to use a helper that's not included by default (say, because you removed helper :all from ApplicationController), just include the helper.

>> include BogusHelper
>> helper.bogus
=> "bogus output"

As for dealing with controllers, I quote Nick's answer:

> app.get '/posts/1'
> response = app.response
# you now have a rails response object much like the integration tests

> response.body            # get you the HTML
> response.cookies         # hash of the cookies

# etc, etc

Here's one way to do this through the console:

>> foo = ActionView::Base.new
=> #<ActionView::Base:0x2aaab0ac2af8 @assigns_added=nil, @assigns={}, @helpers=#<ActionView::Base::ProxyModule:0x2aaab0ac2a58>, @controller=nil, @view_paths=[]>

>> foo.extend YourHelperModule
=> #<ActionView::Base:0x2aaab0ac2af8 @assigns_added=nil, @assigns={}, @helpers=#<ActionView::Base::ProxyModule:0x2aaab0ac2a58>, @controller=nil, @view_paths=[]>

>> foo.your_helper_method(args)
=> "<html>created by your helper</html>"

Creating a new instance of ActionView::Base gives you access to the normal view methods that your helper likely uses. Then extending YourHelperModule mixes its methods into your object letting you view their return values.

Another way to do this is to use the Ruby on Rails debugger. There's a Ruby on Rails guide about debugging at http://guides.rubyonrails.org/debugging_rails_applications.html

Basically, start the server with the -u option:

./script/server -u

And then insert a breakpoint into your script where you would like to have access to the controllers, helpers, etc.

class EventsController < ApplicationController
  def index
    debugger
  end
end

And when you make a request and hit that part in the code, the server console will return a prompt where you can then make requests, view objects, etc. from a command prompt. When finished, just type 'cont' to continue execution. There are also options for extended debugging, but this should at least get you started.

The earlier answers are calling helpers, but the following will help for calling controller methods. I have used this on Ruby on Rails 2.3.2.

First add the following code to your .irbrc file (which can be in your home directory)

class Object
   def request(options = {})
     url=app.url_for(options)
     app.get(url)
     puts app.html_document.root.to_s
  end
end

Then in the Ruby on Rails console you can type something like...

request(:controller => :show, :action => :show_frontpage)

...and the HTML will be dumped to the console.

For controllers, you can instantiate a controller object in the Ruby on Rails console.

For example,

class CustomPagesController < ApplicationController

  def index
    @customs = CustomPage.all
  end

  def get_number
    puts "Got the Number"
  end

  protected

  def get_private_number
    puts 'Got private Number'
  end

end

custom = CustomPagesController.new
2.1.5 :011 > custom = CustomPagesController.new
 => #<CustomPagesController:0xb594f77c @_action_has_layout=true, @_routes=nil, @_headers={"Content-Type"=>"text/html"}, @_status=200, @_request=nil, @_response=nil>
2.1.5 :014 > custom.get_number
Got the Number
 => nil

# For calling private or protected methods,
2.1.5 :048 > custom.send(:get_private_number)
Got private Number
 => nil

If you have added your own helper and you want its methods to be available in console, do:

  1. In the console execute include YourHelperName
  2. Your helper methods are now available in console, and use them calling method_name(args) in the console.

Example: say you have MyHelper (with a method my_method) in 'app/helpers/my_helper.rb`, then in the console do:

  1. include MyHelper
  2. my_helper.my_method
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