XML.Linq - get value based on another value

Question

I am trying to user Linq to XML to pull out a value from some xml based on another value..

Here is my xml

<Lead>
<ID>1189226</ID>
<Client>
    <ID>8445254</ID>
    <Name>City of Lincoln Council</Name>
</Client>
<Contact>
    <ID>5747449</ID>
    <Name>Fred Bloggs</Name>
</Contact>
<Owner>
    <ID>36612</ID>
    <Name>Joe Bloggs</Name>
</Owner>
<CustomFields>
    <CustomField>
      <ID>31961</ID>
      <Name>Scotsm_A_n_Authority_Good</Name>
      <Boolean>true</Boolean>
    </CustomField>
    <CustomField>
      <ID>31963</ID>
      <Name>Scotsma_N_Need Not Want</Name>
      <Boolean>false</Boolean>
    </CustomField>
 </CustomFields>

So, for example, I want to try and get the value of <Boolean> in the <CustomField> where <Name> equals "Scotsm_A_n_Authority_Good" which should be "true"

I have tried the following:

var xmlAnswers = xe.Element("CustomFields").Element("CustomField").Element("Scotsm_A_n_Authority_Good");

But I get an error saying that:

The ' ' character, hexadecimal value 0x20, cannot be included in a name...

Can anyone help please?

Answer 1

You're looking for the wrong thing at the moment. You should be looking for a CustomField element with a Name element with the specified value :

string target = "Scotsm_A_n_Authority_Good"; // Or whatever
var xmlAnswers = xe.Element("CustomFields")
                   .Elements("CustomField")
                   .Where(cf => (string) cf.Element("Name") == target);

This will give you all the matching CustomField elements. You can then get the Boolean value with something like:

foreach (var answer in xmlAnswers)
{
    int id = (int) answer.Element("ID");
    bool value = (bool) answer.Element("Boolean");
    // Use them...
}

(You could extract the ID and value in the LINQ query of course...)

Answer 2

Here is an xml linq solution

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;

namespace ConsoleApplication93
{
    class Program
    {
        static void Main(string[] args)
        {
            string xml =
                "<Lead>" +
                    "<ID>1189226</ID>" +
                    "<Client>" +
                        "<ID>8445254</ID>" +
                        "<Name>City of Lincoln Council</Name>" +
                    "</Client>" +
                    "<Contact>" +
                        "<ID>5747449</ID>" +
                        "<Name>Fred Bloggs</Name>" +
                    "</Contact>" +
                    "<Owner>" +
                        "<ID>36612</ID>" +
                        "<Name>Joe Bloggs</Name>" +
                    "</Owner>" +
                    "<CustomFields>" +
                        "<CustomField>" +
                          "<ID>31961</ID>" +
                          "<Name>Scotsm_A_n_Authority_Good</Name>" +
                          "<Boolean>true</Boolean>" +
                        "</CustomField>" +
                        "<CustomField>" +
                          "<ID>31963</ID>" +
                          "<Name>Scotsma_N_Need Not Want</Name>" +
                          "<Boolean>false</Boolean>" +
                        "</CustomField>" +
                     "</CustomFields>" +
                 "</Lead>";
            XDocument doc = XDocument.Parse(xml);

            //to get all customField
            var results = doc.Descendants("CustomField").Select(x => new
            {
                id = (int)x.Element("ID"),
                name = (string)x.Element("Name"),
                boolean = (Boolean)x.Element("Boolean")
            }).ToList();
            //to get specific
            XElement Scotsm_A_n_Authority_Good = doc.Descendants("CustomField")
                .Where(x => ((string)x.Element("Name") == "Scotsm_A_n_Authority_Good") && (Boolean)(x.Element("Boolean"))).FirstOrDefault();


        }
    }

}