REXML::ParseException does not have a valid root

Question

I get the following error when I attempt to make a json post request:

REXML::ParseException (The document "{\"user\":1,\"email\":\"some@email.com\"}:" does not have a valid root):

Not sure where to start.

My header looks like this:

Accept:application/json, text/javascript, */*; q=0.01
Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8
Connection:keep-alive
Content-Length:38
Content-Type:application/x-www-form-urlencoded
Cookie:_washapp_session=SOME_COOKIE_STRING
Host:myapp.herokuapp.com
Origin:http://myapp.herokuapp.com
Referer:http://myapp.herokuapp.com/user/1/add_friends
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/536.5 (KHTML, like Gecko) Chrome/19.0.1084.52 Safari/536.5
X-CSRF-Token:k5bxjBJ3SCMhe1ILfChoiy6qwkYfVsg0JYZV9KDnwIg=
X-Requested-With:XMLHttpRequest

Answer 1

Content-Type should be application/json. Accept just specifies how you want the information returned, Content-Type describes what you're sending.

You can specify the data type using $.post:

$.post("http://myapp.herokuapp.com/user/1/add_friends", 
    {user:1, email:"some@email.com"},
    function(data){
        processResponse(data);
    }, 
    "json");