Reading Specific Set Of XML Nodes via LINQ

Question

I have an XML file that looks like this...

<return>
  <availableOptions>
    <premiums>
      <item>
        <productCode>Poroduct Code 1</productCode>
        <productDescription>Product Desc 1</productDescription>
        <coverageCode>Coverage Code 1</coverageCode>
        <coverageDescription>Coverage Description 1</coverageDescription>
      </item>
      <item>
        <productCode>Poroduct Code 2</productCode>
        <productDescription>Product Desc 2</productDescription>
        <coverageCode>Coverage Code 2</coverageCode>
        <coverageDescription>Coverage Description 2</coverageDescription>
        <coverageOptions>
          <item>
            <label>label here</label>
            <value>true</value>
            <key>key</key>
          </item>
          <item>
            <label>label here</label>
            <value>true</value>
            <key>key</key>
          </item>
        </coverageOptions>
        <surcharges/>
      </item>
      <item>
         etc...
      </item>
      <item>
         etc...
      </item>
    </premiums>
  </availableOptions>
</return>

My goal is to: find all the unique coverageCodes

I have the following LINQ code:

XDocument xdoc = XDocument.Load("data.xml");

var linq = from item in xdoc.Descendants("premiums").Descendants("item")
            select new
            {
                ProductCode = item.Element("productCode").Value,
                CoverageCode = item.Element("coverageCode").Value
            };

foreach (var node in linq)
{
    Console.WriteLine("Product Code: " + node.ProductCode + ", Coverage Code: " + node.CoverageCode);
}

The first <item> outputs correctly. However, when it gets to the second <item> it throws an error Object reference not set to an instance of an object because it's looking for the productCode and coverageCode in the coverageOptions/item node, but there isn't any.

I do not want it to look there.

How can i have the LINQ just focus on the first <item> instead? I also would like the productCode and coverageCode to be distinct. In this XML file, there are multiple <item> that have the same productCode and coverageCode nodes.

Thank you very much in advance!

Answer 1

How can i have the LINQ just focus on the first <item> instead?

I assume you don't just want the very first <item> , but each top-level <item> . Just change Descendants("item") to Elements("item") . That way it will only look for immediate children of premiums instead of all descendant elements.

For the distinct part, you should be able to just use linq.Distinct() . Anonymous types implement equality and hash code generation appropriately. (It will only look for distinct combinations , mind you - if you have two items with the same product code but different coverage codes for example, they will still be viewed as distinct.)