Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Why do I have trouble using linq on XML with namespaces?

Posted on 2010-08-27
4
Medium Priority
?
762 Views
Last Modified: 2013-11-11
Hello,

I have a class that parses XML from a string and sets the values from the XML to the class properties. I can parse an XML string fine except when a tag has a namespace attribute (xmlns). When I have the namespace included I get an index out of range error on the .ElementAt(0).

An exmaple of _responseXML is

<NetConnectResponse xmlns="http://www.experian.com/NetConnectResponse">
  <CompletionCode>0000</CompletionCode>
  <ReferenceId></ReferenceId>
  <Products xmlns="http://www.experian.com/ARFResponse">
    <CreditProfile>
      <Header>
        <ReportDate>08222010</ReportDate>
        <ReportTime>161300</ReportTime>
        <Preamble>TCA5</Preamble>
        <ARFVersion>07</ARFVersion>
      </Header>
      ...
      ...

Thanks for the help!
-gtar


//load response into XDoc
        xdoc = XDocument.Parse(_responseXML);

 
       //create assimble reportDateTime
        var header = from h in xdoc.Descendants("Header")
                     select new
                     {
                         ReportDate = h.Element("ReportDate").Value,
                         ReportTime = h.Element("ReportTime").Value
                     };

        //set linq vars to local vars
        string rawDate = header.ElementAt(0).ReportDate;
        string rawTime = header.ElementAt(0).ReportTime;

Open in new window

0
Comment
Question by:gtar
4 Comments
 
LVL 21

Accepted Solution

by:
chapmanjw earned 2000 total points
ID: 33547859
Here is Microsoft's article on using XML namespaces with LINQ: http://msdn.microsoft.com/en-us/library/bb669152.aspx
0
 
LVL 27

Expert Comment

by:nmarun
ID: 33547967
Try something like this:

xdoc = XDocument.Parse(_responseXML);
XNamespace xNamespace = "http://www.experian.com/ARFResponse";

//create assimble reportDateTime
var header = from h in xdoc.Descendants(xNamespace + "Header")
             select new
             {
                   ReportDate = h.Element(xNamespace + "ReportDate").Value,
                   ReportTime = h.Element(xNamespace + "ReportTime").Value
             };

Arun

0
 
LVL 64

Expert Comment

by:Fernando Soto
ID: 33548048
Hi gtar;

I have corrected the code you placed in the question. You have two issues. One is that you need to use the namespace for the nodes that it is assigned to in the XML, see code snippet comments and two the query would never execute because it needs to be enumerated so I added the ToList() which will do the job.

Fernando
//load response into XDoc
xdoc = XDocument.Parse(_responseXML);

// Namespace to be used for child elements off the Root node
// except for the element Products and its child nodes which have 
// another namespace. 
XNamespace rns = "http://www.experian.com/NetConnectResponse";
// Namesapce to be used on the Products element and it child nodes
XNamespace pns = "http://www.experian.com/ARFResponse";

//create assimble reportDateTime
var header = (from h in xdoc.Descendants(pns + "Header")
              select new
              {
                  ReportDate = h.Element(pns + "ReportDate").Value,
                  ReportTime = h.Element(pns + "ReportTime").Value
              }).ToList();

//set linq vars to local vars
string rawDate = header.ElementAt(0).ReportDate;
string rawTime = header.ElementAt(0).ReportTime;

Open in new window

0
 

Author Comment

by:gtar
ID: 33548076
All that was needed for my query to execute was to include the root <NetConnectResponse> namespace in the query.

I was able to execute the query without the toList() method. I'm unclear as to why this is needed. Are you saying that if I had several <Header> values that the ToList would ad them to a list and that my original query would not?

Thanks for all your help!

I awarded chapmanjw with the points because I read the suggested msdn article and resolved my problem before I saw the rest of the posts.

Do you have a better approach to accessing the header data. It seems awkward to do the following

header.ElementAt(0).ReportDate

Thanks again,
Gtar

        XNamespace xNamespace = "http://www.experian.com/NetConnectResponse";

        //create assimble reportDateTime
        var header = from h in xdoc.Descendants(xNamespace + "Header")
                     select new
                     {
                         ReportDate = h.Element(xNamespace + "ReportDate").Value,
                         ReportTime = h.Element(xNamespace + "ReportTime").Value
                     };

Open in new window

0

Featured Post

Get your Conversational Ransomware Defense e‑book

This e-book gives you an insight into the ransomware threat and reviews the fundamentals of top-notch ransomware preparedness and recovery. To help you protect yourself and your organization. The initial infection may be inevitable, so the best protection is to be fully prepared.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article shows how to deploy dynamic backgrounds to computers depending on the aspect ratio of display
This article aims to explain the working of CircularLogArchiver. This tool was designed to solve the buildup of log file in cases where systems do not support circular logging or where circular logging is not enabled
In response to a need for security and privacy, and to continue fostering an environment members can turn to for support, solutions, and education, Experts Exchange has created anonymous question capabilities. This new feature is available to our Pr…
Screencast - Getting to Know the Pipeline
Suggested Courses

927 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question