Question

I have the following xml. Given, a UID, Manufacturer Name and Image Layout, I want to pull out all possible sizes that exist in the xml.

<Rules>
  <UniqueID UID="123413">
    <Manufacturer Name="XYZ Company">
      <Image Layout="Portrait">
        <Size rows="512" cols="512" price="x" />
        <Size rows="1024" cols="1024" price="y" />
      </Image>
    </Manufacturer>
  </UniqueID>
</Rules>

The way i do it right now is:

XElement rules = XElement.Parse(xmlDoc.OuterXml);

var uids = rules.Elements("UniqueID")
                .Where(x=> (string)x.Attribute("UID")=="123413")
                .ToList();

foreach(var uid in uids)
{
    var manufacturers = uid.Elements(("UniqueID")
                           .Where(x=> (string)x.Attribute("Name")=="XYZ Company")
                           .ToList();
}

and so on until I have a collection of the possible sizes.

So I am using 3 foreach loops. Is there a better way acheive this with probably one line of code, using LINQ?

Answer 1

It’s a little bit of a mouthful, but you can use XPathSelectElements:

 var sizes = rules.XPathSelectElements("//UniqueId[@UID = '123413']/Manufacturer[@Name = 'XYZ Company']//Size");

Obviously, you could use string formatting to dynamically insert values for @UID and @Name.

Make sure to include System.Xml.XPath.