Detecting empty or missing nodes

conolan · August 11th, 2010, 05:40 AM

I'm parsing XMl with Microsoft.XMLDOM. My problem is sometimes a node is empty or missing (when exporting XML from Excel) and I get an error.
So, how do I test for teh existance of a named node and whether it is empty or not?
Example below is missing para2 node (because it was empty). However if the client edited the XML in notepad, a node might exist thus <subhead></subhead>

<news>
<headline>AlphaWireless to exhibit at 4GWorld in Chicago</headline>
<subhead> Oct 19-21, 2010</subhead>
<para1>See us on stand 106. See http://4gworld.com for details.</para1>
<subdate>10/08/2010</subdate>
<expiredate>01/11/2010</expiredate>
<ID>2</ID>
</news>

Martin Honnen · August 11th, 2010, 06:13 AM

Code:

Dim doc
Set doc = CreateObject("Msxml2.DOMDocument.3.0")
doc.async = False
If doc.load(Server.MapPath("file.xml")) Then
  doc.setProperty "SelectionLanguage", "XPath"
  Set para2El = doc.selectSingleNode("news/para2")
  If para2El Is Nothing Then
    ' element does not exist, handle that here
  Else
    ' element does exist
    If para2El.hasChildNodes() Then
      ' para2El is not empty
    End If
  End If
End If

conolan · August 11th, 2010, 06:44 AM

Excellent. So hard to find that info online, everyone assumes all xml nodes present.