Getting XML data from attributes in C#

Question

I have an API that returns data in XML. The relevant part of the XML looks like this:

<data name="Rows">
   <data Name="Row">
     <data name="CONTACT">John Smith</data>
     <data name="PHONE1">(555)123-4567</data>
   </data>
   <data Name="Row">
     <data name="CONTACT">Jim Smith</data>
     <data name="PHONE1">(555)123-6754</data>
   </data>
</data>

I can get a collection of nodes of each Row with this:

var query = from item in xdoc.Root.Descendants("data")
            where (string)item.Attribute("Name") == "Row"
            select item;

And a collection of strings for each element if I filter by attribute:

var query2 = from item in query.Elements("data")
             where (string)item.Attribute("name") == "CONTACT" 
             select item;

returns: John Smith, James Smith

But I can't figure out how to get each contact name and phone number together.

Something like:

foreach(var row in query)
{
    contact = query.???;
    phone1 = query.????;
}

Answer 1

You need to use your first query to get collection of row elements. Then for each element you need to look for children with desired attribute:

// Find all elements  <data Name="Row">
var query = from item in xdoc.Root.Descendants("data")
     where (string)item.Attribute("Name") == "Row"
     select item;

// Loop through the elements
foreach(var row in query)
{
    // find child element, that has attribute Name="CONTACT"
    var contactElement = row.Descendants("data")
        .Where(x=>(string)x.Attribute("Name") == "CONTACT")
        .First();
    // find child element, that has attribute Name="PHONE1"
    var phoneElement = row.Descendants("data")
        .Where(x=>(string)x.Attribute("Name") == "PHONE1")
        .First();
    // get values of found elements
    var contact = contactElement.Value;
    var phone1 = phoneElement.Value;
}

Above code assumes that you will always have all elements, so function First() is used. If some elements might be missing, you need to handle that accordingly.

Answer 2

Since in your XML all the nodes are data , using Descedants may result in unexpected results as it will find all the nodes no matter where it is present. I will go step by step:-

1) From the root node find all the elements using xdoc.Root.Elements("data") this will give you two nodes with attribute Name as Row .
2) Now from the collection retrieved in step 1, find the first data which have name attribute as CONTACT or PHONE1 .
3) Simply project the items retrieved in step 2.

 var res = from item in xdoc.Root.Elements("data")
           let ContactRow = item.Elements("data")
                            .FirstOrDefault(x => (string)x.Attribute("name") == "CONTACT")
           let PHONE1Row = item.Elements("data")
                            .FirstOrDefault(x => (string)x.Attribute("name") == "PHONE1")
           select new
                 {
                    Contact = (string)ContactRow,
                    Phone1 = (string)PHONE1Row
                 };

Or With Method Syntax:-

 var result = xdoc.Root.Elements("data")
                  .Select(x =>
                       {
                           var ContactRow = x.Elements("data")
                            .FirstOrDefault(z => (string)z.Attribute("name") == "CONTACT");
                           var PHONE1Row = x.Elements("data")
                            .FirstOrDefault(z => (string)z.Attribute("name") == "PHONE1");
                           return new
                                  {
                                     Contact = (string)ContactRow,
                                     Phone1 = (string)PHONE1Row
                                  };
                       });

Answer 3

Or try this

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string xml =
                "<data name=\"Rows\">" +
                   "<data Name=\"Row\">" +
                     "<data name=\"CONTACT\">John Smith</data>" +
                     "<data name=\"PHONE1\">(555)123-4567</data>" +
                   "</data>" +
                   "<data Name=\"Row\">" +
                     "<data name=\"CONTACT\">Jim Smith</data>" +
                     "<data name=\"PHONE1\">(555)123-6754</data>" +
                   "</data>" +
                "</data>";

            XElement doc = XElement.Parse(xml);

            var results = doc.Descendants().Where(x => (string)x.Attribute("Name") == "Row").Select(x => new {
               contact = x.Elements().Where(y => (string)y.Attribute("name") == "CONTACT").FirstOrDefault().Value,
               phone = x.Elements().Where(y => (string)y.Attribute("name") == "PHONE1").FirstOrDefault().Value,
            }).ToList();
        }
    }
}
​