XPATHS and Default Namespaces

Question

What is the story behind XPath and support for namespaces? Did XPath as a specification precede namespaces? If I have a document where elements have been given a default namespace: ``` <foo xmlns="uri" /> ``` It appears as though some of the XPath processor libraries won't recognize `//foo` because of the namespace whereas others will. The option my team has thought about is to add a namespace prefix using regular expressions to the XPath (you can add a namespace prefix via XmlNameTable) but this seems brittle since XPath is such a flexible language when it comes to node tests. Is there a standard that applies to this? My approach is a bit hackish but it seems to work fine; I remove the `xmlns` declaration with a search/replace and then apply XPath. ``` string readyForXpath = Regex.Replace(xmldocument, "xmlns=\".+\"", String.Empty ); ``` Is that a fair approach or has anyone solved this differently?

Accepted Answer

I tried something similar to what palehorse proposed and could not get it to work. Since I was getting data from a published service I couldn't change the xml. I ended up using XmlDocument and XmlNamespaceManager like so:

```
XmlDocument doc = new XmlDocument();
doc.LoadXml(xmlWithBogusNamespace);            
XmlNamespaceManager nSpace = new XmlNamespaceManager(doc.NameTable);
nSpace.AddNamespace("myNs", "http://theirUri");

XmlNodeList nodes = doc.SelectNodes("//myNs:NodesIWant",nSpace);
//etc
```

XPATHS and Default Namespaces

Solution

Problem