VB.NET and XML parsing

AlexPonnath
AlexPonnath used Ask the Experts™
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Ok below is a rough layout of my file i am trying to parse. I was wondering how i can loop thru all Call elements /node in the CDR's
to extract its values. Also how can i check if the calls node has subnotes since that is not always the case. to make it more clear i attached the complete sample data  

<File>
  <FileHeader></FileHeader>
     <CDRs>
          <Call><RoutingInfo></RoutingInfo> </Call>
          <Call> </Call>
       </CDRs>
      <FileFooter></FileFooter>
</File>
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Fernando SotoRetired
Distinguished Expert 2017

Commented:
Hi

From your XML file shown here re-formatted.
<File>
  <FileHeader></FileHeader>
    <CDRs>
      <Call>
        <RoutingInfo>
        </RoutingInfo>
      </Call>
      <Call> </Call>
    </CDRs>
  <FileFooter></FileFooter>
</File>

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Using Linq to XML you can get a list of values from your document so that you do not have to loop through the nodes. The question is what values do you want to have returned to you, for example will they have Attributes or just inner text and which ones you want back? For the Call nodes it would be desirable to have attributes and not inner text because if you return the inner  text of those that have child elements the text from the child elements will also be in the Call node value.  This would not be the case for the RoutingInfo nodes because they do not have children.

To your question, "how can i check if the calls node has subnotes since that is not always the case", Linq to XML has a method HasElements which returns a Boolean if it has True and False for no. The following code snippet show one way to do what you need.
'' Load the XML into memory from the file system
Dim xdoc = XDocument.Load("Data.xml")
'' Get all the Call nodes with children if they have any
Dim results = (From n In xdoc.Root.Descendants("Call")
               Select New With {
                  .CallVal = n.Attribute("value").Value,
                  .HasChildren = n.HasElements
               }).ToList

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Using the Following XML document.
<File>
  <FileHeader></FileHeader>
    <CDRs>
      <Call value="1">
        <RoutingInfo>
        	Routing Value
        </RoutingInfo>
      </Call>
      <Call value="2"></Call>
    </CDRs>
  <FileFooter></FileFooter>
</File>

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From Visual Studio the results look like the following.How the results look like

Author

Commented:
I am a bit confused here, for one or the other reason neither my or your code works against my file..
sample2.xml
Retired
Distinguished Expert 2017
Commented:
Hi Alex;

The reason that neither your code or my code works with the XML that you are using is that the XML you are using contains a name space attribute on the document. In order to get the results you need to reference that name space. Here is my code modified to work with the name space that is defined in the Root element.
'' Load the XML into memory from the file system
Dim xdoc = XDocument.Load("CallData.xml")
Dim ns = xdoc.Root.Name.Namespace

'' Get all the Call nodes with children if they have any
Dim results = (From n In xdoc.Root.Descendants(ns + "Call")
               Select New With {
                  .CallVal = n.Attribute("seqnum").Value,
                  .HasChildren = n.HasElements
               }).ToList

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Author

Commented:
Thanks, that somewhat proofs why my code didn't work. But i  don't want to use Linq or datasets since i have existing logic which handles my parsing. The only problem is it doesn't work with namespace.
So what do i have to do to be able to pretty much read my XML file, and get all Call nodes so i can process them and find subnodes etc.
Fernando SotoRetired
Distinguished Expert 2017

Commented:
Please see your other post.
Fernando SotoRetired
Distinguished Expert 2017

Commented:
Hi Alex;

To your statement, " But i  don't want to use Linq or datasets since i have existing logic which handles my parsing", this was not stated in this question and therefore you got a generalized code that would do the job. Seeming you now know why my code snippet gave you issues was with the Xml Namespace that was not stated in the original question but once you posted the actual schema of the XML the updated code snippet solved the issue.

Please close this question with the solution that worked and if you still have issues with the more specific code please post in the other question you have on this subject.

Thank you and have a great day.

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