How to get to specific node and retrieve data

Question

Heres my XML

 <metadata created="2015-02-24T17:50:40.188Z" xmlns="http://example.com" xmlns:ext="http://example.com">
  <customer-group-list count="10">
    <customer-group id="790174c22752" type="Corporate">
      <title>Mr</title>
      <primary-type>Corporate</primary-type>
      <customer-credit>
        <name-credit>
          <customer id="3d57f91ecf5e">
            <name>Michael Jackson</name>
            <sort-name>Jackson, Michael</sort-name>
            <alias-list>
              <alias sort-name="JACKSON MICHAEL JOE">JACKSON MICHAEL JOE</alias>
            </alias-list>
          </customer>
        </name-credit>
      </customer-credit>
    </customer-group>
    </customer-group-list>
    </metadata>

Im trying to get the (Customer ID), So i have this code

XDoc = XDocument.Parse(XDoc.ToString());

GetCustomers = from c in XDoc.Descendants(ns + "customer-group")
               select
               new Customer
               {
                   ID = c.Element(ns + "customer-credit").Elements(ns + "name-credit").Any()
                     ? c.Element(ns + "customer").Attribute(ns + "id").Value
                     : "",
                   Title = c.Element(ns + "title").Value,
               };

So the ID line of code is where im attempting to nest into the node i need and then get the ID but i get "Object not set to an instance" error and not sure if theres a way to do this or not?

I thought i understood this but if you are posting an answer i would appreciate any explanation of how to get to nested Elements in this fashion.

Thanks

Answer 1

The problem in your code is in the ID line

? c.Element(ns + "customer").Attributes(ns + "id").Value

You can not just jump to an inner element like that. if you want the query to work you can use

? c.Descendants(ns + "customer").Attributes("id").Value

If you can figure out a solution with the hint. This is the full code

void static Main()
{
    var xml= @"<metadata created=""2015-02-24T17:50:40.188Z"" xmlns=""http://example.com"" xmlns:ext=""http://example.com"">
<customer-group-list count=""10"">
    <customer-group id=""790174c22752"" type=""Corporate"">
    <title>Mr</title>
    <primary-type>Corporate</primary-type>
    <customer-credit>
        <name-credit>
        <customer id=""3d57f91ecf5e"">
            <name>Michael Jackson</name>
            <sort-name>Jackson, Michael</sort-name>
            <alias-list>
            <alias sort-name=""JACKSON MICHAEL JOE"">JACKSON MICHAEL JOE</alias>
            </alias-list>
        </customer>
        </name-credit>
    </customer-credit>
    </customer-group>
    </customer-group-list>
    </metadata>";

    XNamespace nameSpace  = "http://example.com";
    XElement dataSet1Tree = XElement.Parse(xml);
    var dataSet1List = from cg in dataSet1Tree.Descendants(nameSpace +"customer-group")
                    let customer = cg.Descendants(nameSpace +"customer").FirstOrDefault()
                    let title  = cg.Descendants(nameSpace +"title").FirstOrDefault()

                    select new {
                                    ID =   customer == null ? "" : customer.Attributes("id").First().Value,
                                    Title = title == null? null : title.Value
                                };

    foreach(var cust in dataSet1List)
    {
        Console.WriteLine(cust.ID +" " + cust.Title);
    }

}