Identify GET and POST parameters in Ruby on Rails

Question

What is the simplest way to identify and separate GET and POST parameters from a controller in Ruby on Rails, which will be equivalent to $_GET and $_POST variables in PHP?

Answer 1

You can use the get? and post? methods to distinguish between HTTP Gets and Posts.

• See http://api.rubyonrails.org/classes/ActionController/AbstractRequest.html

Answer 2

I think what you want to do isn't very "Rails", if you know what I mean. Your GET requests should be idempotent - you should be able to issue the same GET request many times and get the same result each time.

Answer 3

I don't know of any convenience methods in Rails for this, but you can access the querystring directly to parse out parameters that are set there. Something like the following:

request.query_string.split(/&/).inject({}) do |hash, setting|
  key, val = setting.split(/=/)
  hash[key.to_sym] = val
  hash
end

Answer 4

If you want to check the type of request in order to prevent doing anything when the wrong method is used, be aware that you can also specify it in your routes.rb file:

map.connect '/posts/:post_id', :controller => 'posts', :action => 'update', :conditions => {:method => :post}

or

map.resources :posts, :conditions => {:method => :post}

Your PostsController's update method will now only be called when you effectively had a post. Check out the doc for resources.

Answer 5

You don't need to know that level of detail in the controller. Your routes and forms will cause appropriate items to be added to the params hash. Then in the controller you just access say params[:foo] to get the foo parameter and do whatever you need to with it.

The mapping between GET and POST (and PUT and DELETE) and controller actions is set up in config/routes.rb in most modern Rails code.