Parsing SOAP XML with Classic ASP

[Auciker]

I'm typically a LAMP stack developer, so I'm a little out of my comfort zone on this one. I'm working on a classic ASP site that is doing a SOAP based XML API connection. It's worked in the past, but now we're updating the API to connect to a different application. Problem is, I'm not able to get the API to work any more and I've hit a wall with a generic 500 error. I've got detailed error reporting turned on, and this is all it returns:

An error occurred on the server when processing the URL. Please contact the system administrator.

I set up a SOAP client before writing this API, and it tested good. I've run several tests since to be sure that it is still working. I've inserted

Response.Write

statements describing what the code is doing at each step through execution to see which ones show up and which ones do not. It appears to break at this line:

isSuccess = objDoc.getElementsByTagName("Status").text

If it is helpful, here is the full document.

<%@ language=vbscript %>
<% Option Explicit %>
<%
'============================================================'
'   Authenticate a representative using the representative's
'   user name (RepDID or EmailAddress) and password.
'============================================================'

'----------------------------------------------------------'
' Process User Submitted Data
'----------------------------------------------------------'
If Request.ServerVariables("REQUEST_METHOD") = "POST" Then

	'Load form fields into variables
	Response.Write "<p>Loading form fields into variables</p>"
	Dim repUsername, repPassword
	repUsername = Trim(Request.Form("rep-username"))
	repPassword = Trim(Request.Form("rep-password"))

	'Set up basic Validation...
	Response.Write "<p>Validating form</p>"
	If repUsername = "" Or repPassword = "" Then
		Response.Redirect ("../index.asp?login=error#login")

	Else
		'----------------------------------------------------------'
		' Compose SOAP Request
		'----------------------------------------------------------'
		Dim xobj, SOAPRequest
		Set xobj = Server.CreateObject("Msxml2.ServerXMLHTTP")
		xobj.Open "POST", "http://api.domain.com/3.0/Api.asmx", False
		xobj.setRequestHeader "Content-Type", "text/xml; charset=utf-8"
		xobj.setRequestHeader "SOAPAction", "http://api.domain.com/AuthenticateCustomer"
		SOAPRequest = _
		"<?xml version=""1.0"" encoding=""utf-8""?>" &_
			"<x:Envelope xmlns:x='http://schemas.xmlsoap.org/soap/envelope/' xmlns:api='http://api.domain.com/'>"&_
				"<x:Header>" &_
					"<api:ApiAuthentication>" &_
						"<api:LoginName>string</api:LoginName>" &_
						"<api:Password>string</api:Password>" &_
						"<api:Company>string</api:Company>" &_
					"<api:ApiAuthentication>" &_
				"</x:Header>" &_
				"<x:Body>" &_
					"<api:AuthenticateCustomerRequest>" &_
						"<api:LoginName>"&repUsername&"</api:LoginName>" &_
						"<api:Password>"&repPassword&"</api:Password>" &_
					"</api:AuthenticateCustomerRequest>" &_
				"</x:Body>" &_
			"</x:Envelope>"

		Response.Write "<p>Sending SOAP envelope</p>"
		xobj.send SOAPRequest

        '----------------------------------------------------------'
        ' Retrieve SOAP Response
        '----------------------------------------------------------'
		Dim strReturn, objDoc, isSuccess
		Response.Write "<p>Receiving SOAP response</p>"
		strReturn = xobj.responseText 'Get the return envelope

        Set objDoc = CreateObject("Microsoft.XMLDOM")
		objDoc.async = False
		Response.Write "<p>Loading XML</p>"
		objDoc.LoadXml(strReturn)
		Response.Write "<p>Parsing XML</p>"
		isSuccess = objDoc.getElementsByTagName("Status")("Success").text

		'----------------------------------------------------------'
		' If user is valid set Session Authenticated otherwise
		' restrict user and redirect to the index page and show error
		'----------------------------------------------------------'
		Response.Write "<p>Authenticating...</p>"
		If isSuccess = "Success" Then
			Session("Authenticated") = 1
			'Session.Timeout = 1 '60 'Expire session 1 hours from current time
			Response.Redirect ("../welcome.asp#AdvancedTrainingVideos")

		Else
			Session("Authenticated") = 0
			Response.Redirect ("../index.asp?login=error#login")

		End IF 'END - isSuccess

	End IF ' END - Basic Validation...
End IF 'END - REQUEST_METHOD POST

%>

Any insights are very welcome.

[2kaud]

I'm neither a vbscript nor soap person, but I offer this.

In the first part of your post you give

isSuccess = objDoc.getElementsByTagName("Status").text

but in the full document you give

isSuccess = objDoc.getElementsByTagName("Status")("Success").text

[Auciker]

I'm neither a vbscript nor soap person, but I offer this.

In the first part of your post you give

isSuccess = objDoc.getElementsByTagName("Status").text

but in the full document you give

isSuccess = objDoc.getElementsByTagName("Status")("Success").text

Good catch. I've been doing a number of experiments to see if I can get it to work. At one point I entered in the value of the tag as well as the tag name to see if that would do it. The original API from which I modified this one had a boolean reponse in that second field, which was (0). This response is not boolean, but a string "Success". Unfortunately that didn't fix it. Not sure if it broke it more, but it definitely didn't fix it.

[Auciker]

Here's where I'm at. I've installed an ASP host on my computer so I can run locally and get more detailed error reporting. The error is as follows:

Microsoft VBScript runtime error '800a01c2'
Wrong number of arguments or invalid property assignment
/inc/verify.asp, line 69

The line of code in question is as follows:

isSuccess = objDoc.getElementsByTagName("Status")

I've been toying with this line for quite a while now and nothing I do seems to work, though I have been able to generate more types of errors!

[Arjay]

getElementsByTagName returns a list of objects, not a Boolean value.

Refer to https://msdn.microsoft.com/en-us/lib...(v=vs.85).aspx

[Auciker]

getElementsByTaskName returns a list of objects, not a Boolean value.

Refer to https://msdn.microsoft.com/en-us/lib...(v=vs.85).aspx

Hi Arjay! The return I'm getting is supposed to be a string, not boolean, so it sounds like I'm using the right method. However, I am having difficulty figuring out how to take that returned value and successfully load it into my "isSuccess" variable.

[Auciker]

Bump

[Arjay]

Hi Arjay! The return I'm getting is supposed to be a string, not boolean, so it sounds like I'm using the right method. However, I am having difficulty figuring out how to take that returned value and successfully load it into my "isSuccess" variable.

Okay, getElementsByTagName returns a list of objects, not a string.

[Auciker]

Okay, getElementsByTaskName returns a list of objects, not a string.

What is your recommendation on how I could alter the code to get it to work?

BTW, you keep entering "getElementsByTaskName", but the method I'm using is "getElementsByTagName". Is this a typo on your part?

[Arjay]

What is your recommendation on how I could alter the code to get it to work?

BTW, you keep entering "getElementsByTaskName", but the method I'm using is "getElementsByTagName". Is this a typo on your part?

Sorry, I had typo'd the name of the method, but had you clicked on the link I referred you to, you would have seen that it was getElementsByTagName. The link shows the method returns an array of objects and includes a code snippet that shows you how to access the first object.

[Auciker]

I assumed it was a typo, but I wanted to be sure we're on the same page.

I did visit the page, but unfortunately it is not clear to me exactly what I'm supposed to do. As with most code documentation, but I found it to be too obtuse for me. The examples are in Javascript and C++ and I'm working with ASP and VBS.

[2kaud]

What is your recommendation on how I could alter the code to get it to work?

From looking at the article in post #5, I would consider

isSuccess = objDoc.getElementsByTagName("Status")
...
If isSuccess.item(0).text = "Success" Then

or possibly

isSuccess = objDoc.getElementsByTagName("Status").item(0).text
...
If isSuccess = "Success" Then

[Auciker]

From looking at the article in post #5, I would consider

isSuccess = objDoc.getElementsByTagName("Status")
...
If isSuccess.item(0).text = "Success" Then

or possibly

isSuccess = objDoc.getElementsByTagName("Status").item(0).text
...
If isSuccess = "Success" Then

Thanks 2kaud. Unfortunately it's now returning the following error:

Microsoft VBScript runtime error '800a01a8'

Object required: '[object]'

[2kaud]

Which line is causing the error?

[Arjay]

Thanks 2kaud. Unfortunately it's now returning the following error:

Microsoft VBScript runtime error '800a01a8'

Object required: '[object]'

If objDoc.GetElementsByTagName("Status") doesn't find any objects, then attempting to access the first object in a list (with item(0)) is going to result in an error. You need to check if isSuccess is null and isSuccess.item is null (or has values).