Question

I’m trying to work out why my xpath won’t select the nodes I specificy

My xpath expression is //DefaultValue, so I expect all elements of name DefaultValue to be selected

My test file (cut down) is :

<?xml version="1.0" encoding="utf-8"?>
<SharedDataSet xmlns:rd="http://schemas.microsoft.com/SQLServer/reporting/reportdesigner" xmlns="http://schemas.microsoft.com/sqlserver/reporting/2010/01/shareddatasetdefinition">
  <Description />
  <DataSet Name="ddd">
    <Query>
      <DataSourceReference>xxx</DataSourceReference>
      <DataSetParameters>
        <DataSetParameter Name="p1">
          <DefaultValue>baaaah</DefaultValue> <!-- this node should be selected eh? -->
        </DataSetParameter>
        <DataSetParameter Name="p2">
          <DefaultValue>fooo</DefaultValue>   <!-- this node should be selected too eh? -->
        </DataSetParameter>
      </DataSetParameters>
   </Query>
 </SharedDataSet>

Code is :

XmlNamespaceManager xn = new XmlNamespaceManager(new NameTable());
xn.AddNamespace("ns", "http://schemas.microsoft.com/sqlserver/reporting/2010/01/shareddatasetdefinition");
xn.AddNamespace("rd", "http://schemas.microsoft.com/SQLServer/reporting/reportdesigner");
xn.AddNamespace("cl", "http://schemas.microsoft.com/sqlserver/reporting/2010/01/componentdefinition");

XDocument document = XDocument.Parse(reportBuffer, LoadOptions.PreserveWhitespace);
IEnumerable<XElement> elements = document.XPathSelectElements(xpath, xn);

at this point elements.Count() equals 0

Can anyone see what foolishness I present?

I can’t seem to make the xml demons happy… 🙁

Answer 1

The <DefaultValue> element is actually bound to the namespace http://schemas.microsoft.com/sqlserver/reporting/2010/01/shareddatasetdefinition.

The <SharedDataSet> document element has it declared without a prefix, so it is easy to miss. Since <DefaultValue> is a descendant, it inherits the namespace.

If you want to select the <DefaultValue> element you need to adjust your XPath:

//ns:DefaultValue