Params variable not getting filled with JSON post data....Why? - ruby-on-rails

Question

I had this service working before, with some other fields, but right now i seem not to get it working, and am not quite getting why.
I'm posting the following json to my Rails app (with RestClient 2.4, for the test) :
{
"camp":{
"total": 100,
"number": "epw1f6e"
},
"machine":{
"serial_number": "1234567",
"token": "fONxDN"
}
}
Camp controller :
def create
if is_it_json?
logger.debug params.inspect
machine = Machine.find_by_serial_number(params[:machine][:serial_number])
...
From the logger, I get that params are : {"action"=>"create", "controller"=>"camp"}
Where is the json information??
My log error :
Started POST "/camps" for 127.0.0.1 at 2012-07-15 00:08:21 +0100
Processing by CampsController#create as JSON
WARNING: Can't verify CSRF token authenticity
{"action"=>"create", "controller"=>"camps"}
Completed 500 Internal Server Error in 2ms
NoMethodError (undefined method `[]' for nil:NilClass):
app/controllers/camps_controller.rb:24:in `create'
What might i be doing wrong?
Thank you

Answer 1

After a lot of reading and questioning, i just found out the solution :
The params weren't getting filled because i was missing Headers (I had the Accept, but was missing the Content-type) :
Accept: application/json
Content-type: application/json
Adding the headers solved this issue.

Answer 2

Can't verify CSRF token authenticity {"action"=>"create", "controller"=>"camps"}
Completed 500 Internal Server Error in 2ms
That error is thrown when an invalid (or nonexistent) CSRF token is posted with your json. The CSRF needs to be attached to the header of any posted data. For testing you can disable CSRF tokens by adding the following to your controller (for Rails 3):
protect_from_forgery :except => :create
Do not leave that in your controller when the site goes into production. CSRF tokens prevent CSRF attacks. Refer to the Ruby on Rails Security Guide for more details.
Let me know if that does the trick!