Readng XML via LINQ

**tlhintoq** · Feb 3 '10, 03:50 PM

Just guessing that the path "dk.xml" does not lead to a file.
I think the default search is to check in the same folder as the executable.
Perhaps testing with the file a known valid location like "C:\\dk.xml "

**Samishii23** · Feb 3 '10, 04:01 PM

Thanks for the quick response.

I tried putting the XML file in the C:/ . Same result.
I tried using Console.Write instead.
I tried using data.ToString() .

All the "Talent" tags in my XML file with don't have a closing tag (The syntax is w3 compliant though). So I tried to read a tag with a closing tag... Still no go...

Just figured I would try and see if it did anything. Though it didn't seem to work. =\

**Curtis Rutland** · Feb 3 '10, 04:30 PM

I've been meaning to do a writeup of this eventually, but I haven't had time. I'll do a quick condensed version here for you to get started. I really love LINQ and want everyone to start using it =D

First, make sure to add a reference to System.Xml.Linq if you haven't, and make sure it's in your using statements. (I see that you already have, but I'm putting this here for other people's benefit).

The first part of the following code gets all the descendant nodes of the root element in the XML document, then loops through them and prints their values. I used the standard long notation for this.

The second part shows a query to find a specific string in the xml, namely the value of the first descendant node called "body". I used shorthand and a lambda expression for this example.

Here's a sample that can get you started.
C# Program

Code:

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

namespace TermsHelper
{
    class Program
    {
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(@"c:\dev\temp.xml");

            //standard notation
            var data = from x in doc.Root.Descendants()
                       select x;
            foreach (XElement e in data)
                Console.WriteLine(e.Value);

            //alternate notation
            string body = doc.Root.Descendants().Where(x => x.Name == "body").First().Value;

            Console.WriteLine("\nBody: {0}", body);

            //attribute example
            string attribute = doc.Root.Descendants().Where(x => x.Name == "body").First().Attribute("type").Value;
            Console.WriteLine("\nAttribute: {0}", attribute);
            Console.Read();
        }
    }
}

temp.xml

Code:

<?xml version="1.0"?>
<note>
    <to>Tove</to>
    <from>Jani</from>
    <heading>Reminder</heading>
    <body type="text">Don't forget me this weekend!</body>
</note>

Expected output when executed

Code:

Tove
Jani
Reminder
Don't forget me this weekend!

Body: Don't forget me this weekend!

Attribute: text

Good luck.

**Samishii23** · Feb 3 '10, 06:31 PM

Don't suppose I could get a quickie example pertaining to attributes?

**Curtis Rutland** · Feb 3 '10, 06:49 PM

Sure, I'll edit my original post to include an attribute example.

Attribute("name ") is a method of XElement that returns the first XAttribute of the XElement that matches the name. Attributes() will return a list.

**Samishii23** · Feb 3 '10, 08:24 PM

Awesome. I believe I've got the hang of singular Linq'n here. lol
This is a quickie layout of my current XML file.

Code:

<base>
  <tree1>
    <tag1 />
    ...
    <tag44 />
  </tree1>
  ...
  <tree3 />
</base>

So far I've wrote this:

Code:

var query = from x in xmldoc.Root.Descendants()
    select (XElement)x.Element("Talent");

And when I console it. I get Tag1 from each of the 3 trees and then a $hit ton of White Space. And thats it... lol

What I want to do is basicly read each Tag into a List or Array. All the examples I can find half the time either just give me a single item return, or they create an XML which I will not be doing at all.

**Curtis Rutland** · Feb 3 '10, 08:44 PM

This would work better:

Code:

var query = from x in xmldoc.Root.Descendants().Elements("Talent")
    select x;

Here's an example that uses your sample XML and does what you want in two different ways. The first way just gets all the elements who's name contains the string "tag". The second uses a custom data type and nested LINQ queries to give you a list of trees, with each tree containing a list of tags.

Code:

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

namespace TermsHelper
{
    class Program
    {
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(@"c:\dev\temp.xml");

            //just tags
            List<XElement> elements = (from x in doc.Root.Descendants()
                                      where x.Name.LocalName.Contains("tag")
                                      select x).ToList();

            foreach (XElement e in elements)
                Console.WriteLine(e.Name);

            Console.WriteLine();

            //custom data type, hierarchical

            List<Tree> trees = (from x in doc.Root.Descendants()
                                where x.Name.LocalName.Contains("tree")
                                select new Tree
                                {
                                    TreeName = x.Name.ToString(),
                                    Tags = (from y in x.Elements()
                                            where y.Name.LocalName.Contains("tag")
                                            select y).ToList()
                                }).ToList();

            foreach (Tree t in trees)
            {
                Console.WriteLine("Tree Name: {0}", t.TreeName);
                Console.WriteLine("Tags:");
                foreach (XElement e in t.Tags)
                    Console.WriteLine(e.Name);
                Console.WriteLine();
            }

            Console.Read();
        }
    }
    public class Tree
    {
        public string TreeName { get; set; }
        public List<XElement> Tags { get; set; }
    }
}

Contents of temp.xml

Code:

<?xml version="1.0"?>
 <base>
   <tree1>
     <tag1 />
	 <tag2 />
     <tag44 />
   </tree1>
   <tree2>
	<tag1 />
   </tree2>
   <tree3 />
</base>

Expected Output

Code:

tag1
tag2
tag44
tag1

Tree Name: tree1
Tags:
tag1
tag2
tag44

Tree Name: tree2
Tags:
tag1

Tree Name: tree3
Tags:

**Samishii23** · Feb 12 '10, 01:56 AM

Well. Thanks for all the help! Though this LINQ stuff is a headache, and I doubt I'll be learning much more since just trying to figure out your examples, I couldn't really figure it out. Most tutorials out there do more XML generation rather then reading. Especially the MSDN examples... Ugh.

This is what I came up with...

Code:

XDocument xmldoc = XDocument.Load("dk.xml");
	var query = from x in xmldoc.Root.Descendants()
			where x.Name == "Talent"
			select x;
	foreach (XElement q in query)
	{
		Console.Write(q.Name + ": ");
		Console.Write(q.Attribute("id").Value + ",");
		if (Int32.Parse(q.Attribute("pts").Value) > 0)
		{
			Console.Write(q.Attribute("pts").Value + ",");
			Console.Write(q.Attribute("title").Value + ",");
			Console.Write(q.Attribute("icon").Value);
			if (q.LastAttribute.Name == "req")
				Console.Write("," + q.Attribute("req").Value);
		}
		else
		{
    		Console.Write(q.Attribute("pts"));
		}
	Console.WriteLine("--");

Output is:

Code:

Tag: 1,5,title,icon
Tag: 2,0
... (132 total)

Each "Tag" output will be listed in its own List.

**Samishii23** · Feb 12 '10, 06:10 PM

So ok. Now my next question... Using the above code... How would I get a sibling node ( if thats what its called? ) through the same loop?

Would I use another Decendant() call?

Code:

<talent>
  <disc>
    Some stuff here
  </disc>
</talent>

**Curtis Rutland** · Feb 12 '10, 06:14 PM

Code:

q.Element["whatever"].Value

Should give you the value of the first child node named "whatever"

**Samishii23** · Feb 13 '10, 12:38 AM

The " [] " brackets didn't work, but the " () " did. Thanks!

**Curtis Rutland** · Feb 13 '10, 06:04 AM

Oops, sorry, forgot it was a method and not an index.

Readng XML via LINQ

Readng XML via LINQ

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