[jdom-interest] xpath [constructing path as you walk the tree ]

[Laurent Bihanic]

Hi,

Dan Douglas wrote:
> "Gu Xueying (Shinnie Gu)" <Shinnie.Gu at iuniverse.com.cn> writes:
> 
>>I want to get the path of each element when I walk through the jdom tree.
> 
> If you're already "walking" the tree, wouldn't it be easier and more
> efficient to just construct the path as you move down the tree? 
> 
But this is actually quite difficult if Gu wants to get the exact XPath 
selecting the current node as this may require an XPath expression with a test 
subexpression.
For example, in the following document:
<a>
  <b>
   <c>1</c>
   <d>2</d>
   <c>3</c>
   <d>4</d>
  </b>
</a>
selecting the node <c>3</c> requires building an XPath expression like
   /a/b/c[position() = '2']
or
   /a/b/*[position() = '3']

Given on document, building the XPath requires both walking the document tree 
up to the root and the sibling list.
If you code this, Gu, it would make a good helper class to add to jdom-contrib!

Laurent