Reputation: 4844
<Document>
<A>
<B>
<C></C>
</B>
</A>
<E>
<F>
<C></C>
</F>
<G>
<C></C>
</G>
</E>
</Document>
If i load the above XML into an XmlDocument and do a SelectSingleNode on A using the XPath query //C
XmlNode oNode = oDocument.SelectSingleNode("E"); XmlNodeList oNodeList = oNode.SelectNodes("//C");
why does it return nodes from Under B when what I would expect to happen would that it only return nodes from under E
Make sense?
Edit : How would i make it only return from that node onwards?
Upvotes: 19
Views: 31197
Reputation: 22777
//C
is all C nodes in the entire document
/E//C
would be only C nodes under E
/C
would be only the root C node
See the xpath syntax reference
Upvotes: 6
Reputation: 62397
Specifying .//C
will achieve what you want, otherwise, the XPath starts from the document root rather than the current node.
The confusion is in the definition of //
from the XPath standard as follows:
// is short for /descendant-or-self::node()/. For example, //para is short for /descendant-or-self::node()/child::para and so will select any para element in the document (even a para element that is a document element will be selected by //para since the document element node is a child of the root node); div//para is short for div/descendant-or-self::node()/child::para and so will select all para descendants of div children.
Because //
is short for /descendant-or-self::node()/
it starts at the document level unless you specify a node at the start.
Upvotes: 11
Reputation: 22859
In the XPATH Specification you will find under 2.5 the following statement:
//para selects all the para descendants of the document root and thus selects all para elements in the same document as the context node
i.e. the behaviour you observe is valid. You should do something like "/E//C"
Upvotes: 3
Reputation: 1063884
Simply: a leading // means "at any level" in the same document as the selected node.
From the spec:
Upvotes: 29