Question

I have xml that looks like this. I’m been stuck for a while on trying to add more values to the Author element.

I load it in like so:

XDocument cdata = XDocument.Parse(text);

here is the sample xml:

<a xmlns="http://www" version="5.050">  
  <Books>
   <Author> Poe,Edgar Allen Homer Walden</Author>
   <Address></Address>
   <State></State>
 </Books>
 <SYSTEM type="OTHER">
   <ORGANIZATION id="" />
 </SYSTEM>
 <HMDA_INFO is_hoepa="N" is_hoepa_manual="N" />
</a>

Just a side note ‘a’ is not necessarily always the root element name sometimes its b or c so I can’t go by the root name.

Tried doing this to access Author but I get sequence contains no elements:

XDocument cdata = XDocument.Parse(text);
var addElement = cdata.Descendants("Books").First();
addElement.SetAttributeValue("Authors", "insert this.");

Answer 1

You have two problems. First is that Author is an element, not attribute. And second – you forgot about namespace declared in a element:

XDocument cdata = XDocument.Parse(text);
XNamespace ns = "http://www";
var books = cdata.Descendants(ns + "Books").First();
var author = books.Element(ns + "Author"); 
author.Value = "insert this." + authors.Value;

Or if you want just to add new attribute to authors element:

books.Element(ns + "Author").SetAttributeValue(ns + "Foo", "insert this.");