Need for NewDataSet when processing data from web service

I'm retrieving some data from a webservice as follows

        Dim RestXML As New Data.DataSet
        Dim returnedXML As System.Xml.XmlDataDocument

        RestXML.ReadXml(functionURL)
        returnedXML = New XmlDataDocument(RestXML)

The return is something like this..

  <?xml version="1.0" encoding="utf-8" ?>
- <CallResults>
    - <ServiceOutput>
          <accountBalance>46.5</accountBalance>
          <rentalPrice>3.5</rentalPrice>
          <purchasePrice>6.5</purchasePrice>
      </ServiceOutput>
    - <ServiceResult>
      <ResultCode>01</ResultCode>
      <ResultAdvisory>message</ResultAdvisory>
      </ServiceResult>
  </CallResults>

I extract the Result code as follows

        strReturncode = returnedXML.DocumentElement.SelectSingleNode("/
CallResults/ServiceResult/ResultCode").InnerText

However with different input parameters to functionURL the XML
returned can be as follows (ServiceOutput is empty)

 <?xml version="1.0" encoding="utf-8" ?>
- <CallResults>
      <ServiceOutput />
    - <ServiceResult>
          <ResultCode>00</ResultCode>
          <ResultAdvisory>Message</ResultAdvisory>
      </ServiceResult>
  </CallResults>

In this case there is a failure unless I add "/NewDataSet" to identify
which element I want to extract as follows.

        strReturncode = returnedXML.DocumentElement.SelectSingleNode("/
NewDataSet/CallResults/ServiceResult/ResultCode").InnerText

Am I retrieving the response from the web service correctly. How can I
process it so that it works whether ServiceOutput is empty or not.

Thanks for reading.

Date:Wed, 15 Aug 2007 02:06:19 -0700 Author:

Re: Need for NewDataSet when processing data from web service

wrote in message 
news:1187168779.072339.278700@22g2000hsm.googlegroups.com...

> I'm retrieving some data from a webservice as follows
>
>        Dim RestXML As New Data.DataSet
>        Dim returnedXML As System.Xml.XmlDataDocument
>
>        RestXML.ReadXml(functionURL)
>        returnedXML = New XmlDataDocument(RestXML)
>
> The return is something like this..
>
>  <?xml version="1.0" encoding="utf-8" ?>
> - <CallResults>
>    - <ServiceOutput>
>          <accountBalance>46.5</accountBalance>
>          <rentalPrice>3.5</rentalPrice>
>          <purchasePrice>6.5</purchasePrice>
>      </ServiceOutput>
>    - <ServiceResult>
>      <ResultCode>01</ResultCode>
>      <ResultAdvisory>message</ResultAdvisory>
>      </ServiceResult>
>  </CallResults>
>
> I extract the Result code as follows
>
>        strReturncode = returnedXML.DocumentElement.SelectSingleNode("/
> CallResults/ServiceResult/ResultCode").InnerText
>
> However with different input parameters to functionURL the XML
> returned can be as follows (ServiceOutput is empty)
>
> <?xml version="1.0" encoding="utf-8" ?>
> - <CallResults>
>      <ServiceOutput />
>    - <ServiceResult>
>          <ResultCode>00</ResultCode>
>          <ResultAdvisory>Message</ResultAdvisory>
>      </ServiceResult>
>  </CallResults>
>
> In this case there is a failure unless I add "/NewDataSet" to identify
> which element I want to extract as follows.
>
>        strReturncode = returnedXML.DocumentElement.SelectSingleNode("/
> NewDataSet/CallResults/ServiceResult/ResultCode").InnerText
>
> Am I retrieving the response from the web service correctly. How can I
> process it so that it works whether ServiceOutput is empty or not.


It would seem that you would have the same problem regardless of where you 
got this XML from. Try loading the problem XML directly into an XmlDocument 
and see if the problem still occurs.
-- 
John Saunders [MVP]

Date:Wed, 15 Aug 2007 09:38:49 -0400 Author: