Posting data using XMLHttpRequest

Hi,

I need to post the data using XMLHttpRequest. While posting, few values have to be passed in the URL like http://site.com?var1=value1&var2=value2 and few values have to be sent as form data.

Please suggest how to construct the required headers and message format to post the data in this format using XMLHttpRequest in VB Script.

If I try to set the URL as http://site.com?var1=value1&var2=value2 for the open method of XMLHttpRequest and the other values related form data by specifying content-disposition and the name of the variable and trying to send the data, looks like the variable values passed in the URL doesn't seem to be recognized by the target server.

Thanks in advance,

Raghu

It's difficult to help you if you don't say what site it is AND post your code.

Probably don't need to know what site it is, but it sounds like you've tried something already and it didn't work - it'd be helpful to post the code you tried.

Here is the portion of the code I have used to post the data using XMLHttpRequest object

Code:

---

        Const MULTIPART_BOUNDARY = "9876543210----------0123456789"

        Dim strResponse, xmlhttp, xmlDom, returnVal
        Dim strData

        strData = ""

        strData = strData & "--" & MULTIPART_BOUNDARY & vbCrLf
        strData = strData & "Content-Disposition: form-data; name=""message""" & vbCrLf & vbCrLf
        strData = strData & strMessage
        strData = strData & vbCrLf

        strData = strData & "--" & MULTIPART_BOUNDARY & "--"

        Set xmlhttp = CreateObject("Microsoft.XMLHTTP")
        xmlhttp.open "POST", "http://mysite.com?environmentId=Development", false

        xmlhttp.SetRequestHeader "Accept", "application/x-www-form-urlencoded,text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"
        xmlhttp.SetRequestHeader "Accept-Language", "en-us,en;q=0.5"
        xmlhttp.SetRequestHeader "Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7"
        xmlhttp.SetRequestHeader "Content-Type", "multipart/form-data; boundary=" & MULTIPART_BOUNDARY
        xmlhttp.SetRequestHeader "Content-Length", Len(strData) + 2
        xmlhttp.Send strData

        'If the state of the request is 4 then get the response and parse it
        If xmlhttp.readyState = 4 Then
                'Get the response and set it to a string
                strResponse = xmlhttp.responseText       

                'Create DOM object reference and parse the xml string
                Set xmlDom = CreateObject("Msxml2.DOMDocument")
                xmlDom.loadxml(strResponse)
                'Echo if any error while parsing
                If xmlDom.parseerror.errorcode <> 0 Then
                        Wscript.echo "Reason for the error:" & xmlDom.parseerror.reason
                Else
                        retVal = xmlDom.text
                        Wscript.echo "Reason for the error:" & retVal
                End If
        End If

---

In the above code, I passing environmentID value as part of URL and message value as a form variable as the server expects the data in this format. But based on the response from the server it appears that Environment ID value is not recognized. As the server returns that as the error, I am not sure whether the message variable passed in the form data is recognized or not. The message parameter value is an XML which will be read from an XML file (Not shown in the code). I am not sure whether is it required to set the message type or not.

Please suggest what is wrong in the above code for my requirement.

I don't see anything wrong here, and testing it out for myself worked correctly (environmentID was recognized). Do you have access to the code on the server? Do you know how it's trying to access that variable?

Hi,

I do not have access to the code on the server. However, I tried posting it again. Looks like environmentID is recognized. However, message value that is passed like form data is not recognized. Is something wrong in constructing the form data to be sent to the server?

Thanks in advance.

Raghu

Your strData should be set up in the following format:

Code:

---

strData = "var1=value1&var2=value2"

---

Etc. I don't believe you need anything about content disposition or any other data in the string except for variable and value pairs.

Hi,

I have simulated my requirement by creating a web page that posts the data to the server and verified HTTP headers sent by the browser. The browser used the content-type as application/x-www-form-urlencoded and the XML file content also encoded to URL format, which I was not doing in my code. Following code worked fine for my requirement.

Code:

---

        Dim strResponse, xmlhttp, xmlDom, returnVal
        Dim strMessage

        Set xmlhttp = CreateObject("Microsoft.XMLHTTP")
        xmlhttp.open "POST", "http://mysite.com?environmentId=Development", false

        xmlhttp.SetRequestHeader "Content-Type", "application/x-www-form-urlencoded"
        xmlhttp.SetRequestHeader "Accept", "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, */*"
        xmlhttp.SetRequestHeader "Accept-Language", "en-us"
        xmlhttp.SetRequestHeader "Accept-Encoding", "gzip, deflate"

        'Send the request synchronously by converting the encoding the message to be sent
        xmlhttp.send "message=" & escape(strMessage)

        'If the state of the request is 4 then get the response and parse it
        If xmlhttp.readyState = 4 Then
                'Get the response and set it to a string
                strResponse = xmlhttp.responseText       

                'Create DOM object reference and parse the xml string
                Set xmlDom = CreateObject("Msxml2.DOMDocument")
                xmlDom.loadxml(strResponse)
                'Echo if any error while parsing
                If xmlDom.parseerror.errorcode <> 0 Then
                        Wscript.echo "Reason for the error:" & xmlDom.parseerror.reason
                Else
                        retVal = xmlDom.text
                        Wscript.echo "Reason for the error:" & retVal
                End If
        End If

---

Thank you,
Raghu