How to read multiple CodeTables within XML Form

Question

I have multiple Code Tables at the bottom of the XML that I am processing and I would like to lookup a code that comes from the top portion of the XML and get the CodeText from a table at the bottom of the XML.

Here are two of the CodeTables:

<CodeTable Name="Codes - Days of Week">
  <CodeText CodeValue="" /> 
  <CodeText CodeValue="1">SUNDAY</CodeText> 
  <CodeText CodeValue="2">MONDAY</CodeText> 
  <CodeText CodeValue="3">TUESDAY</CodeText> 
  <CodeText CodeValue="4">WEDNESDAY</CodeText> 
  <CodeText CodeValue="5">THURSDAY</CodeText> 
  <CodeText CodeValue="6">FRIDAY</CodeText> 
  <CodeText CodeValue="7">SATURDAY</CodeText> 
</CodeTable>
<CodeTable Name="Codes - Bus Type">
  <CodeText CodeValue="" /> 
  <CodeText CodeValue="0">NOT A BUS</CodeText> 
  <CodeText CodeValue="1">SCHOOL (PUBLIC OR PRIVATE)</CodeText> 
  <CodeText CodeValue="2">TRANSIT</CodeText> 
  <CodeText CodeValue="3">INTERCITY</CodeText> 
  <CodeText CodeValue="4">CHARTER</CodeText> 
  <CodeText CodeValue="5">OTHER</CodeText>
</CodeTable>

I am able to use the following lines of code to get to the code table:

string CodeTableName = "Codes - Days of Week";
XmlNode CodeTableNode = doc.SelectSingleNode("//CodeTable[@Name=\"" + Convert.ToString(CodeTableName) + "\"]");

And I have been able to use the following to get the CodeText for Bus Type = 0:

XmlNode CodeTextNode = doc.SelectSingleNode("//CodeText[@CodeValue=\"" + Convert.ToString(BusCode) + "\"]");
code_text = CodeTextNode.InnerText;
Console.WriteLine(code_text);    

What I would like to be able to do is put both of these together somehow? So I can get to the CodeTable I need and then pull the correct CodeText based on the CodeValue.

Answer 1

If you use LinqToXml you could do the following:

using System.Linq;
using System.Xml.Linq;

// [...]
var codeKey = "0";
var name = "Codes - Bus Type";

var doc = XDocument.Load("bla");
var code = doc.Descendants().Where(
        d => d.Name == "CodeText" &&
        d.Parent.Attribute("Name").Value == name &&
        d.Attribute("CodeValue").Value == codeKey).FirstOrDefault().Value;

In productive code I'd make sure that you first check for null before the last .Value call. But otherwise this should work.