My JSON-RPC client (browser using dojo JSON-RPC) makes a JSON-RPC request (dojo.callRemote) to my JSON-RPC server on myserver.com/12345 (Python 2.5, SimpleJSONRPCServer).
The server then gets a HTTP request with header “OPTIONS / HTTP/1.1”, which it can’t handle by default, so I wrote a custom handler for this request.
The request header from the browser says:
OPTIONS / HTTP/1.1
Host: myserver:12345
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100214 Linux Mint/8 (Helena) Firefox/3.5.8 (.NET CLR 3.5.30729)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.7,de;q=0.3
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Origin: http://myserver.com
Access-Control-Request-Method: POST
Access-Control-Request-Headers: x-requested-with
And the response I’m sending looks like this:
HTTP/1.0 200 OK
Server: BaseHTTP/0.3 Python/2.5
Date: Mon, 05 Apr 2010 18:58:34 GMT
Access-Control-Allow-Method: POST
Access-Control-Allow-Headers: POST
Allow: POST
Content-Type: application/json-rpc
Content-length: 0
But in the browser I get the following error:
Error: Unable to load http://myserver.com:12345 status:0
I verified that the JSON-Service is reachable from the net.
Now the question is, what does the browser (say, Firefox) expect the response hearders to say? Or maybe the problem lies elsewhere?
See the CORS Specification.
(BTW; there’s a header registry for HTTP, see http://www.iana.org/assignments/message-headers/prov-headers.html and http://www.iana.org/assignments/message-headers/perm-headers.html, which would have pointed you to the right spec).