How can an XSL template call itself?

I´m about to generate a plain text file from a variable XML source by using XSL. The problem is that every time the transform would take place, the XSL doesn´t know what the tree structure of the XML is.
The only aproach I thought of was to add recursion by making the XSL browse the tree for children nodes and, for each one found call itself again and so on.

Something like this:







0">
has child






Can anyone give me a hand?