Rails: How do I print the request parameters?

Question

I have a Rails 3 application and I want to print in the view the request parameters. How do I do it?

Edit:

The purpose is to see what is being sent in a Form

Answer 1

Source: http://guides.rubyonrails.org/getting_started.html#creating-articles

When a form is submitted, the fields of the form are sent to Rails as parameters. These parameters can then be referenced inside the controller actions, typically to perform a particular task. To see what these parameters look like, change the create action to this:

def create
  render plain: params[:article].inspect
end

---

The response when POST'ing a form to the targeted #create route would be a plain-text hash output of params[:article]

Answer 2

Learnt this from the Ruby Hero James Edward Gray II on this episode of Ruby Rogues podcast which I highly recommend. raise is a swiss army knife for inspecting anything in your Rails code which prints it nicely on your browser.

raise params.inspect

Answer 3

You can use for models, controllers, etc.

puts YAML::dump(params)

Source: Ruby / Rails alternative to PHP print_r() and var_dump()

For views:

DebugHelper’s debug(object)

In your case:

DebugHelper’s debug(params)

Answer 4

Parameters are stored in the params hash. For example, if there was a title parameter, you could display it in your view using <%= params[:title] %>.

Answer 5

Something like

<%= params.inspect %>

works, but what I would like to add is the following gem and Chrome plugin which was literally an eye-opener.

I am putting it here because I think it will help people check out params hashes, see SQL queries or view Errors.

Answer 6

I would use debug(params). That will give you a nicely formatted view of them.