VBScript and loadXML: Invalid at the top level of the document. How to fix it?

Question

This is my fort post on stackoverflow. I have searched many similiar Q&A's on this site but my conditions seem a bit different. here is my vbscript code:

------------ code snippet ---------------

xmlurl = "songs.xml"

set xmlDoc = CreateObject("Microsoft.XMLDOM")
xmlDoc.async = False
xmlDoc.loadXML(xmlurl)

if xmlDoc.parseError.errorcode<>0 then
  'error handling code
  msgbox("error! " & xmlDoc.parseError.reason)
end if

------------ end code snippet ---------------

XML:

<?xml version="1.0" encoding="UTF-8"?>
<nowplaying-info-list>
  <nowplaying-info mountName="CKOIFMAAC" timestamp="1339771946" type="track">
    <property name="track_artist_name"><![CDATA[CKOI]]></property>
    <property name="cue_title"><![CDATA[HITMIX]]></property>
  </nowplaying-info>
  <nowplaying-info mountName="CKOIFMAAC" timestamp="1339771364" type="track">
    <property name="track_artist_name"><![CDATA[AMYLIE]]></property>
    <property name="cue_title"><![CDATA[LES FILLES]]></property>
  </nowplaying-info>
  <nowplaying-info mountName="CKOIFMAAC" timestamp="1339771149" type="track">
    <property name="track_artist_name"><![CDATA[MIA MARTINA]]></property>
    <property name="cue_title"><![CDATA[TOI ET MOI]]></property>
  </nowplaying-info>
</nowplaying-info-list>

I also tried removing the first line in case maybe UTF-8 was not compatible with windows (saw some posts about this), but I still got the same error. I also tried unix2dos and vice versa in case there were carriage return issues (hidden characters embedded in the xml). I just can't seem to figure out what's wrong. It's such a simole XML file. I could parse it in a few minutes using perl regex but I need to run this script on windows so using vbscript. I use the same technique to parse XML from other sources without any issues. I cannot modify the XML unfortunately, it is from an external source. I have this exact same error on both my Windows Vista home edition and Windows Server 2008. I am running the vbscript from the command line for testing so far (ie not in ASP).

Thanks in advance,

Sam

Answer 1

xmlDoc.loadXML() can load an XML string. It cannot retrieve a URL.

Use an XMLHTTPRequest object if you need to make an HTTP request.

Function LoadXml(xmlurl)
  Dim xmlhttp

  Set xmlhttp = CreateObject("MSXML2.XMLHTTP")
  xmlhttp.Open "GET", xmlurl, false

  ' switch to manual error handling
  On Error Resume Next

  xmlhttp.Send
  If err.number <> 0 Then 
    WScript.Echo xmlhttp.parseError.Reason
    Err.Clear
  End If 

  ' switch back to automatic error handling 
  On Error Goto 0

  Set LoadXml = xmlhttp.ResponseXml
End Function

Use like

Set doc = LoadXml("http://your.url/here")

Answer 2

Three addition remarks:

(1) As .parseError.reason tends to be cryptic, it pays to include its .srcTxt property (and the parameter to .loadXml):

  Dim xmlurl : xmlurl = "song.xml"
  Dim xmlDoc : Set xmlDoc = CreateObject("Microsoft.XMLDOM")
  xmlDoc.async = False
  xmlDoc.loadXML xmlurl
  If 0 <> xmlDoc.parseError.errorcode Then
     WScript.Echo xmlDoc.parseError.reason, "Src:", xmlDoc.parseError.srcText
  Else
     WScript.Echo "surprise, surprise"
  End if

output:

Invalid at the top level of the document.
 Src:  song.xml

Of course, writing a Function/Sub that takes all properties of .parseError into account and using that always, would be even better.

(2) To load a file or URL, use .load:

  Dim xmlDoc : Set xmlDoc = CreateObject("Microsoft.XMLDOM")
  Dim xmlurl
  For Each xmlurl In Array("song.xml", "http://gent/~eh/song.xml", "zilch")
    xmlDoc.async = False
    if xmlDoc.load(xmlurl) Then
       With xmlDoc.documentElement.firstChild
          WScript.Echo    xmlurl _
                       , .tagName _
                       , .firstChild.tagName _
                       , .firstChild.text
       End With
    Else
       WScript.Echo xmlurl, xmlDoc.parseError.reason, "Src:", xmlDoc.parseError.srcText
    End if
  Next

output:

song.xml nowplaying-info property CKOI-ÄÖÜ
http://gent/~eh/song.xml nowplaying-info property CKOI-ÄÖÜ
zilch The system cannot locate the object specified.
 Src:

(3) Using the DOM avoids all encoding problems (that's why I put some german umlauts into 'your' file - which even made it to the DOS-Box output) and makes RegExps (even Perl's) a second best choice.