Question

Is there a way to search an XDocument without knowing the namespace? I have a process that logs all SOAP requests and encrypts the sensitive data. I want to find any elements based on name. Something like, give me all elements where the name is CreditCard. I don’t care what the namespace is.

My problem seems to be with LINQ and requiring a xml namespace.

I have other processes that retrieve values from XML, but I know the namespace for these other process.

XDocument xDocument = XDocument.Load(@"C:\temp\Packet.xml");
XNamespace xNamespace = "http://CompanyName.AppName.Service.Contracts";

var elements = xDocument.Root
                        .DescendantsAndSelf()
                        .Elements()
                        .Where(d => d.Name == xNamespace + "CreditCardNumber");

I really want to have the ability to search xml without knowing about namespaces, something like this:

XDocument xDocument = XDocument.Load(@"C:\temp\Packet.xml");
var elements = xDocument.Root
                        .DescendantsAndSelf()
                        .Elements()
                        .Where(d => d.Name == "CreditCardNumber")

This will not work because I don’t know the namespace beforehand at compile time.

How can this be done?

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <Request xmlns="http://CompanyName.AppName.Service.ContractA">
        <Person>
            <CreditCardNumber>83838</CreditCardNumber>
            <FirstName>Tom</FirstName>
            <LastName>Jackson</LastName>
        </Person>
        <Person>
            <CreditCardNumber>789875</CreditCardNumber>
            <FirstName>Chris</FirstName>
            <LastName>Smith</LastName>
        </Person>
        ...

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <Request xmlns="http://CompanyName.AppName.Service.ContractsB">
        <Transaction>
            <CreditCardNumber>83838</CreditCardNumber>
            <TransactionID>64588</FirstName>
        </Transaction>      
        ...

Answer 1

As Adam precises in the comment, XName are convertible to a string, but that string requires the namespace when there is one. That’s why the comparison of .Name to a string fails, or why you can’t pass “Person” as a parameter to the XLinq Method to filter on their name.
XName consists of a prefix (the Namespace) and a LocalName. The local name is what you want to query on if you are ignoring namespaces.
Thank you Adam 🙂

You can’t put the Name of the node as a parameter of the .Descendants() method, but you can query that way :

var doc= XElement.Parse(
@"<s:Envelope xmlns:s=""http://schemas.xmlsoap.org/soap/envelope/"">
<s:Body xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"">
  <Request xmlns=""http://CompanyName.AppName.Service.ContractA"">
    <Person>
        <CreditCardNumber>83838</CreditCardNumber>
        <FirstName>Tom</FirstName>
        <LastName>Jackson</LastName>
    </Person>
    <Person>
        <CreditCardNumber>789875</CreditCardNumber>
        <FirstName>Chris</FirstName>
        <LastName>Smith</LastName>
    </Person>
   </Request>
   </s:Body>
</s:Envelope>");

EDIT : bad copy/past from my test 🙂

var persons = from p in doc.Descendants()
              where p.Name.LocalName == "Person"
              select p;

foreach (var p in persons)
{
    Console.WriteLine(p);
}

That works for me…