you must use a browser that supports and has JavaScript enabled - c#

Question

Am trying to post using HTTPWebrequest and this is the response i keep getting back:

you must use a browser that supports and has JavaScript enabled

This is my post code:

HttpWebRequest myRequest = null;
myRequest = (HttpWebRequest)HttpWebRequest.Create(submitURL);
myRequest.Headers.Add("Accept-Language", "en-US");
myRequest.Accept = "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*";
myRequest.Method = WebRequestMethods.Http.Post;
myRequest.Headers.Add("Accept-Language", "en-US");
myRequest.Accept = "*/*, text/xml";
myRequest.ContentType = "application/x-www-form-urlencoded" + "\n" + "\r";
myRequest.CookieContainer = cookieContainer;
myRequest.Headers.Add("UA-CPU", "x86");
myRequest.Headers.Add("Accept-Encoding", "gzip, deflate");

//cPostData section removed as submitting to SO

myRequest.ContentLength = cPostData.Length;

myRequest.ServicePoint.Expect100Continue = false;

StreamWriter streamWriter = new System.IO.StreamWriter(myRequest.GetRequestStream());
streamWriter.Write(cPostData);
streamWriter.Close();


HttpWebResponse httpWebResponse = (HttpWebResponse)myRequest.GetResponse();
StreamReader streamReader = new System.IO.StreamReader(httpWebResponse.GetResponseStream());
string stringResult = streamReader.ReadToEnd();
streamReader.Close();

how do i avoid getting this error?

Answer 1

It is difficult to say what the exact problem is because the server that is receiving you request doesn't think it is valid.

Perhaps the first thing to try would be to set the UserAgent property on your HttpWebRequest to some valid browser's user agent string as the server may be using this value to determine whether or not to serve the page.

Answer 2

This doesn't have anything to do with your code - the web server code has something that detects or relies on Javascript. Most likely a piece of Javascript on the page fills out (or modifies prior to posting) some hidden form field(s).

The solution to this is entirely dependent on what the web server is expecting to happen with that form data.

Answer 3

This is a layman's answer, and not a 100% technically accurate description of the httpWebRequest object, and meant that way bcause of the amount of time it would take to post it. The first part of this answer is to clarify the final sentence.

The httpWebRequest object basically acts as a browser that is interacting with web pages. It's a very simple browser, with no UI. it's designed basically to be able to post to and read from web pages. As such, it does not support a variety of features normally found in a browser these days, such as JavaScript.

The page you are attempting to post to requires javascript, which the httpWebRequest object does not support. If you have no control over the page that the WebRequst object is posting to, then you'll have to find another wat to post to it. If you own or control the page, you will need to modify the page to strip out items that require javascript (such as Ajax features, etc).

Added

I purposely didn't add anything about specifying a user-agent to try to trick the web server into thinking the httpWebRequest object supports JavaScript. because it is likely that the page really needs to have JavaScript enabled in order for the page to be displayed properly. However, a lot of my assumptions prove wrong, so I would agree with @Andrew Hare and say it's worth a try.