Cross-origin resource sharing (CORS) post request works from plain javascript, but why not with jQuery
ajax, cherrypy, cors, jquery
Solution
I finally stumbled upon this link "A CORS POST request works from plain javascript, but why not with jQuery?" that notes that jQuery 1.5.1 adds the
Access-Control-Request-Headers: x-requested-with
header to all CORS requests. jQuery 1.5.2 does not do this. Also, according to the same question, setting a server response header of
Access-Control-Allow-Headers: *
does not allow the response to continue. You need to ensure the response header specifically includes the required headers. ie:
Access-Control-Allow-Headers: x-requested-with
Problem
I have a machine on my local lan (machineA) that has two web servers. The first is the in-built one in XBMC (on port 8080) and displays our library. The second server is a CherryPy python script (port 8081) that I am using to trigger a file conversion on demand. The file conversion is triggered by a AJAX POST request from the page served from the XBMC server. - Goto http://machineA:8080 which displays library - Library is displayed - User clicks on 'convert' link which issues the following command - jQuery Ajax Request ``` $.post('http://machineA:8081', {file_url: 'asfd'}, function(d){console.log(d)}) ``` - The browser issues a HTTP OPTIONS request with the following headers; Request Header - OPTIONS ``` Host: machineA:8081 User-Agent: ... Firefox/4.01 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 115 Connection: keep-alive Origin: http://machineA:8080 Access-Control-Request-Method: POST Access-Control-Request-Headers: x-requested-with ``` - The server responds with the following; Response Header - OPTIONS (STATUS = 200 OK) ``` Content-Length: 0 Access-Control-Allow-Headers: * Access-Control-Max-Age: 1728000 Server: CherryPy/3.2.0 Date: Thu, 21 Apr 2011 22:40:29 GMT Access-Control-Allow-Origin: * Access-Control-Allow-Methods: POST, GET, OPTIONS Content-Type: text/html;charset=ISO-8859-1 ``` - The conversation then stops. The browser, should in theory, issue a POST request as the server responded with the correct (?) CORS headers (Access-Control-Allow-Origin: *) For troubleshooting, I have also issued the same $.post command from http://jquery.com. This is where I am stumped, from jquery.com, the post request works, a OPTIONS request is sent following by a POST. The headers from this transaction are below; Request Header - OPTIONS ``` Host: machineA:8081 User-Agent: ... Firefox/4.01 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 115 Connection: keep-alive Origin: http://jquery.com Access-Control-Request-Method: POST ``` Response Header - OPTIONS (STATUS = 200 OK) ``` Content-Length: 0 Access-Control-Allow-Headers: * Access-Control-Max-Age: 1728000 Server: CherryPy/3.2.0 Date: Thu, 21 Apr 2011 22:37:59 GMT Access-Control-Allow-Origin: * Access-Control-Allow-Methods: POST, GET, OPTIONS Content-Type: text/html;charset=ISO-8859-1 ``` Request Header - POST ``` Host: machineA:8081 User-Agent: ... Firefox/4.01 Accept: */* Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 115 Connection: keep-alive Content-Type: application/x-www-form-urlencoded; charset=UTF-8 Referer: http://jquery.com/ Content-Length: 12 Origin: http://jquery.com Pragma: no-cache Cache-Control: no-cache ``` Response Header - POST (STATUS = 200 OK) ``` Content-Length: 32 Access-Control-Allow-Headers: * Access-Control-Max-Age: 1728000 Server: CherryPy/3.2.0 Date: Thu, 21 Apr 2011 22:37:59 GMT Access-Control-Allow-Origin: * Access-Control-Allow-Methods: POST, GET, OPTIONS Content-Type: application/json ``` I can't work out why the same request would work from one site, but not the other. I am hoping someone might be able to point out what I am missing. Thanks for your help!