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Extract data from a XML string using linq vs xmlDocument

I have done the below many times using a xmlDocument approach, but I wanted to use the more powerful linq to xml approach.
However, I seem to have run into a wall.
I am getting data back from a restful API from twillio / crmText.
Here is a link to their site where their docs live:
http://crmtext.com/api/docs
Here is my XML string:
<response op="getcustomerinfo" status="200" message="ok" version="1.0">
<customer>
<totalMsg>3</totalMsg>
<custId>9008281</custId>
<custName></custName>
<timestamp>2015-04-30 16:17:19</timestamp>
<optinStatus>3</optinStatus>
<custMobile>6185551212</custMobile>
<subacct>1st Choice Courier</subacct>
</customer>
</response>
I need to find out the optinStatus. It should return 3.
I am using the below, which return the above xml
XDocument xdoc = XDocument.Parse(result1);
I have tried about 4000 different things, including:
IEnumerable<XElement> otinStatus = from el in xdoc.Elements("customer") select el;
IEnumerable<XElement> otinStatus2 = from el in xdoc.Elements("cusotmer.optinStatus") select el;
IEnumerable<XElement> otinStatus3 = from el in xdoc.Elements("optinStatus") select el;
All of which returns no results.
Please help, I know this is something simple I am missing.
Thank you in advance -- Joe

Retrieve an Element's Value
var status = xDoc
.Descendants("optinStatus") // get the optinStatus element
.Single() // we're expecting a single result
.Value; // get the XElement's value
Example
Here is a working Fiddle for you. You can see it running live here. The output is 3.
using System;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
public class Program
{
public static void Main()
{
var xDoc = XDocument.Parse(xmlString);
var status = xDoc.Descendants("optinStatus").Single();
Console.WriteLine(status.Value);
}
private static string xmlString = #"
<response op=""getcustomerinfo"" status=""200"" message=""ok"" version=""1.0"">
<customer>
<totalMsg>3</totalMsg>
<custId>9008281</custId>
<custName></custName>
<timestamp>2015-04-30 16:17:19</timestamp>
<optinStatus>3</optinStatus>
<custMobile>6185312349</custMobile>
<subacct>1st Choice Courier</subacct>
</customer>
</response>
";
}
Explanation
Descendents() is an instance axes method (or just axes in shorthand). It returns an IEnumerable<XElement> of all matching descendents. On its results, we call Single(). It is a Linq method that returns the only element of a sequence. If there is more than one element, it throws an error. We're left with a single XElement. This represent an entire XML element. Since we only want its value not the entire element, we call the Value property. Bingo, we're done.
A Bit More Detail
Axes come in two kinds:
Instance axes methods, which MSDN lists here, are invokable members of the XElement, XDocument, and XNode classes.
Extension axes methods, which MSDN lists here, are invokable on collections.
With one exception, an axes method returns a collection of type IEnumerable<T>. The exception is Element(), which returns the first matching child object. That what AmatuerDev used and, as in your question, if you are only expecting a single result, it is a just as good if not better approach that is Descendants().
Retrieve an Attribute Value
Once we have an XElement, we can retrieve one of its attributes instead of its value. We do that by calling the Attributes() method. It returns the matching XAttribute. Since we only want the attribute value, we call the Value property. Voila.
// for attribute
var response = xDoc.Descendants("response").Single();
var attr = response.Attribute("status");
General Approach
Using Linq to XML is a two step process.
Call an axes method to obtain an IEnumerable<T> result.
Use Linq to query that.
See Also
Here is some relevant MSDN documentation:
How to: Retrieve the Value of an Element (LINQ to XML)
LINQ to XML Axes

Assuming xDoc being the XDocument. Have you tried..
var customer = xDoc.Root.Element("customer");
var optinStatus = customer.Element("optinStatus");
var optinStatusValue = optinStatus.Value;

How to get a second or third XML node when using an anonymous type?

I'm using an anonymous type to grab some XML data. All was going well until I ran across a section of XML where there can be 2 or 3 similar nodes. Like in the XML sample below there are 3 separate "Phones". My code was working fine when there was only ONE element that was possible to grab after following the "element path" I led it to. How can i grab a specific one? Or all 3 for that matter? Handling XML is still new to me and there seems to be soo many ways of handling it Searching the web for my exact need here didn't prove successful. Thanks.
var nodes = from node in doc.Elements("ClaimsSvcRs").Elements("ClaimDownloadRs")
select new
{
Phone1 = (string)node.Elements("Communications").Elements("PhoneInfo").Elements("PhoneNumber").FirstOrDefault(),
Phone2 = (string)node.Elements("Communications").Elements("PhoneInfo").Elements("PhoneNumber").FirstOrDefault(),
};
The XML Code is
<?xml version="1.0" encoding="UTF-8"?>
<TEST>
<ClaimsSvcRs>
<ClaimDownloadRs>
<Communications>
<PhoneInfo>
<PhoneTypeCd>Phone</PhoneTypeCd>
<CommunicationUseCd>Home</CommunicationUseCd>
<PhoneNumber>+1-715-5553944</PhoneNumber>
</PhoneInfo>
<PhoneInfo>
<PhoneTypeCd>Phone</PhoneTypeCd>
<CommunicationUseCd>Business</CommunicationUseCd>
<PhoneNumber>+1-715-5552519</PhoneNumber>
</PhoneInfo>
<PhoneInfo>
<PhoneTypeCd>Phone</PhoneTypeCd>
<CommunicationUseCd>Cell</CommunicationUseCd>
<PhoneNumber>+1-715-5551212</PhoneNumber>
</PhoneInfo>
</Communications>
</ClaimDownloadRs>
</ClaimsSvcRs>
</TEST>

I haven't used xpath in a while so i'll let someone else stand in there... but there's a way to select a particular PhoneInfo object based upon its subelements. So if you knew whether you wanted Home or Business or Cell or whatever, you'd be able to select that particular PhoneInfo object. Otherwise if you wanted simple Phone1,2,3 and nulls where ok, use the Skip linq function. Phone2 = query.Skip(1).FirstOrDefault()
lol no worries ;) xpath can be intermixed in here, was my thought, and might be more elegant if your CommunicationUseCd fields were deterministic. Then you could have Home = ... and Work = ..., etc, instead of Phone1 & Phone2
The same could be accomplished by slipping a where clause into each your query lines

If you're up for LINQ you can get all your elements in one go:
foreach(XElement phone in XDocument.Parse(xmlString).Descendants("PhoneInfo"))
{
Console.WriteLine(phone.Element("PhoneNumber").Value);
//etc
}
I find XDocument & LINQ a lot easier than XmlDocument & XPath, if you're okay with the alternative. There's more info on them here

What is the proper way to retrieve a value from a single, nested, XElement?

To retieve the value of a nested XElement I have the following in my code:
XElement xml = new XElement("UserDefinedSettings", new XElement("RootFolder", new XElement("FolderName", "User Input Goes Here")));
xml.Save("UserDefinedSettings.xml");
Which gives me this saved to the hard drive:
<?xml version="1.0" encoding="utf-8"?>
<UserDefinedSettings>
<RootFolder>
<FolderName>User Input Goes Here</FolderName>
</RootFolder>
</UserDefinedSettings>
Later, To retrieve the name of the folder that the user has chosen I am using:
XDocument xdoc = XDocument.Load("UserDefinedSettings.xml");
var myVar = xdoc.Descendants("FolderName").Single();
textBox1.Text = myVar.Value;
I am new to Linq-XML and I am wondering if what I have done is the right way to go about it?
Initially I had been using the following line of code to get the name of the folder, but I knew there had to be a better way and after searching here on SO for examples I am using the code above instead.
string s =xdoc.Element("UserDefinedSettings").Element("RootFolder").Element("FolderName").Value;

What you have should be fine (the newer way), as long as you are certain those elements exist. It runs the risk of throwing a null reference exception however if any of them do not exist. I typically query with Elements() rather than Element(). Elements() returns an IEnumerable which you can safely chain together with more Elements() queries (or whatever). For example, you might consider:
var folder = (string)xdoc.Elements("UserDefinedSettings").Elements("RootFolder").Elements("FolderName").FirstOrDefault();
Another thing I typically do when I want the value from an attribute or element is cast my XElements and XAttributes with a string as I did above. A null value cast as a string will return a null string, preventing a null reference exception that you would get with a .Value call.

Also would work:
xdoc.XPathSelectElement("/UserDefinedSettings/RootFolder/FolderName").Value
I prefer to use XPath for it's succinctness but it's your choice.

issue selecting descendants in LINQ to XML

This is driving me a little crazy. I am pulling an XML string from a database column and successfully creating an XDocument using XDocument.Parse. I've used linq to xml before to query xml trees but for some reason on this everything I am doing is returning null. Is it something to do with the namespace?
Here is a sampling of the text visualizer for my XDocument object:
// removed XML for privacy reasons
An example of the query I am trying:
XElement algorithmId = (from algoId in reportLogXml.Descendants(ALGORITHM_ID)
select algoId).FirstOrDefault();
I am using a constant for the string value and I have quadruple checked that the spelling matches as well as trying several different elements that are clearly in the document but they all return null. What am I doing wrong here?

Yes, it probably has to do with the namespace but also the <AlgorithmId> element has no descendants.
You can fix the ns problem like this:
//untested
XNameSpace ns0 = "http://schemas.datacontract.org/2004/07/Adapters.Adapter";
var ns1 = reportLogXml.Root.GetDefaultNamespace();
// check: ns0 and ns1 should be equal here
... in reportLogXml.Descendants(ns1 + ALGORITHM_ID)
Note that this is a special + operator, follow the format exactly.

Can't add items to ListView from my XMLs in WPF

The main problem is this one.
I have 2 XMLs containing information about what my company does. One is considered the template XML where you can find the general information and the other one is the Catalog containing information about each individual equipment, containing a reference to the template XML.
They look like this
Catalog XML
<list>
<A>
<B>
<c>reference to template</c>
<d>info 2</d>
<e>info 3</e>
<f>info 4</f>
<g>
<h>info5</h>
<i>info5</i>
</g>
</B>
<B>
<c>reference to template</c>
<d>info a</d>
<e>info s</e>
<f>info d</f>
<g>
<h>infof</h>
<i>infog</i>
</g>
</B>
<B>
<c>reference to template</c>
<d>info h</d>
<e>info j</e>
<f>info k</f>
<g>
<h>infot</h>
<i>infoy</i>
</g>
</B>
</A>
</list>
Template
<list>
<R>
<S>
<t>info 7</t>
<u>info 8</u>
<v>info 9</v>
<w>info 10</w>
</S>
</R>
</list>
What I need to do is to display all of the equipment catalogued in a listView, which will lits information from both XMLs.
I've tried that and had no succes, all I can display is one equipment, weel it actually isn'y displayed, all that appears is invisible information.
I run through both XMLs using this:
xDocument load = xDocument.load("Myxml.xml");
var run = (from x in load.Descendants("A")
where x.Element("c").Value == comboBox1.SelectedItems.ToString()
select new
{
a = x.Element("d").Valuye.ToString(),
//here I gather the rest of the information
}).ToList();
listView.Items.Add(run);
//after that I tried listview.Items.Add(run.a) ... but the code which I use to run through
//ends with FirstorDefault(), instead of ToList() and I try adding all the components manually
The only thing that Appears is an invisible Equipment, which means that when I click on it I can see there's something there, but I just can't see the information.
So I tried adding strings using the same methodology, but got the same result.
Can anyone please tell me where's my mistake? I can't see it.
PS: After I manage to do this, I'm gonna Implement a function, that by double clicking on the information, the client will be able to alter the information. If someone knows where to start with this one, please point me in the right direction

I believe your linq query needs a bit of a touch up, something like:
xDocument load = xDocument.load("Myxml.xml");
var run = (from x in load.Descendants("B")
where x.Element("c") == comboBox1.SelectedItems.ToString()
select new
{
a = x.Element("d").Valuye.ToString(),
//here I gather the rest of the information
}).ToList();
Also, you should try using a for loop on the list and adding the strings one by one
foreach (var item in run)
listView.Items.Add(item.a);
You can take a look at the different overloads of the Add method on this MSDN page:
http://msdn.microsoft.com/en-us/library/system.windows.forms.listview.listviewitemcollection.aspx

To be honest, I'm not entirely sure what the question is. I'll take a shot at the XDocument query, though.
When doing comparisons, you need to compare the correct types. The comparison from the example won't even compile because there is a comparison of an XElement with a String:
where x.Element("c") == comboBox1.SelectedItems.ToString()
Should be:
where x.Element("c").Value == comboBox1.SelectedItems.ToString()
If the overall goal is to get a list of strings from the query, then take a look at the following:
string match = comboBox1.SelectedItems.ToString();
var doc = XDocument.Load( "MyXml.xml" );
var query = doc.Descendants( "B" )
.Where( x => x.Element( "c" ).Value == match )
.Select( x => x.Element( "d" ).Value )
.ToList();
Notice that the query starts with the "B" element. Starting at the "A" element will result in 0 elements matched in the where clause.
Also, it is easier to break these types of problems down by using additional variables to break down the statement, i.e., variables for the matching criteria, for the XDocument, for the query, etc... Even the query could be broken down into further sub-queries if needed.
This should get you started.

If you are using the Detail mode of the list view, you need to add columns to the list and subitems in the items corresponding to each column, else your items will be "invisible".
See the ListView.Columns and ListViewItem.SubItems members for more details.

I found out what was wrong, I needed to add an observable collection, to which I added the content I wanted to put on the viewlist, and then I put the information in the observablecollection in the viewlist.
Thank you all for helping me.