Simulating submit button using HttpRequest

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fahd - 29 Jul 2008 15:57 GMT

Hi,

I'm trying to run a ccxml, and consequently, a voiceXML page on the
voice server through my application and the documentation of the
server mention that it can be done using HTTP POST.

Following is a sample example of html that works and successfully
starts a ccxml page on a remote destination

<html>
    <body>
        <form method="post" action="http://localhost:4045/basichttp"
enctype="application/x-www-form-urlencoded">
            ID="Form1">
            name: <input type="text" name="name" size="40"
value="OutBoundCallEvent" id="Text1" />

            URI to be contacted by the outbound: <input type="text"
name="ToBeContacted_URI" size="52" value="10.2.50.42" id="Text5" />

            VoiceXML URI: <input type="text" name="VoiceXML_URI" size="73"
value="file:///C:/voiceXML/three.vxml">
                ID="Text6" />

            CCXML URI: <input type="text" name="uri" size="75" value="file:///
C:/CCXML/outboundcall.ccxml">
                ID="Text7" />

            <input type="submit" id="Submit1" name="Submit1">
        </input></input></input></form>
    </body>
</html>

Now I want to achieve the same effect through my c# application and I
am using HttpRequest and HttpResponse to mimic submitting the form
above.

following is my attempt on this

            string uri = @"http://localhost:4045/basichttp";
            string data =
@"name=OutBoundCallEvent&ToBeContacted_URI=10.2.50.42&VoiceXML_URI=file:///
C:/voiceXML/three.vxml&uri=file:///C:/CCXML/outboundcall.ccxml";
            byte [] bytes = System.Text.Encoding.ASCII.GetBytes(data);

            HttpWebRequest req = (HttpWebRequest) WebRequest.Create(uri);
            req.ContentType = "application/x-www-form-urlencoded";
            req.Method = "POST";
            req.ContentLength = bytes.Length;

            System.IO.Stream os = req.GetRequestStream();
            os.Write (bytes, 0, bytes.Length);
            os.Close();

            HttpWebResponse resp = (HttpWebResponse) req.GetResponse();
            if (resp== null)
            {
                MessageBox.Show("Problem in sending response!");
            }

            System.IO.StreamReader sr = new
System.IO.StreamReader(resp.GetResponseStream());
            string result = sr.ReadToEnd().Trim();
            MessageBox.Show("All done!");

Now when I try to get the response using HttpResponse I get an error "
The remote server returned an error: (400) Bad Request."

Q1 Does writing the data into the stream means that the data has been
sent just like pressing the submit button? or does using the
getResponse method do this?
Q2 Is there something im missing in order to achieve a simple submit
function? I have tried sending some data over to an asp page and use
response like above and it all seems to work fine.

Any help will be greatly appreciated.
Kind Regards
Fahd

Reply to this Message

Nicholas Paldino [.NET/C# MVP] - 29 Jul 2008 17:36 GMT

Fahd,

When you press the Submit button on the form, it encodes the fields in
the form (which may contain hidden fields) and then sends that data to the
server.

Your best bet here is to get an HTTP request sniffer (look for Fiddler,
it's free, and will do what you want). Basically, you will be able to issue
the request in your browser of choice, and see how it is sent to the server.
That will help determine the best way to construct the message in code.

Signature

- Nicholas Paldino [.NET/C# MVP]
- mvp@spam.guard.caspershouse.com

> Hi,
>
[quoted text clipped - 74 lines]
> Kind Regards
> Fahd

Reply to this Message

fahd - 31 Jul 2008 16:07 GMT

Hi Nicholas,

Thanks for the tip, im on it.
Just one question if you may

does the following piece of code sends the data to the server

System.IO.Stream os = req.GetRequestStream();
os.Write (bytes, 0, bytes.Length);
os.Close();

or this bit sends data to the server
HttpWebResponse resp = (HttpWebResponse)
req.GetResponse();

Thanks
Fahd

Reply to this Message

fahd - 31 Jul 2008 16:37 GMT

Hi Nicholas,

used fiddler and got to know my mistake the dreaded escape
characters!!!
and I found out answer to my question as well. Thanks a million and
Fiddler is a gem :)

take care
Fahd

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Simulating submit button using HttpRequest

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