Hello,

  Imagine I have the following XML input:

<doc>
 <entry>
  <a>some data</a>
  <b>some data</b>
 </entry>
 <entry>
  <a>more data</a>
  <b>more data</b>
 </entry>
</doc>

  And I want to produce something like this in the output

FILE 1:
<group_a>
 <a>some data</a>
 <a>more data</a>
</group_a>

FILE 2:
<group_b>
 <b>some data</b>
 <b>more data</b>
</group_b>

  I know how to do this kind of transformation in two passes. But can it be done in one pass? I have a really big XML file, and I'd sure like to avoid iterating through its elements multiple times. In other words, can I handle multiple files in the output simultaneously? If so, how?

  Thanks in advance,
   Rodrigo

You can do this in XSLT 2.0 using the xsl:result-document instruction.

You can't do it in standard XSLT 1.0, but several XSLT 1.0 processors provide an extension instruction for the purpose.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Yes, I know about the result-document statement, but I don't know how to use it to do the transformation in a single pass. What I meant from my previous question was that, if a had to separate my XML input in ten different files, I'd have to write ten "for" statements, one for each class I had in mind, generating one file at a time. What I'd like to have is some way to build multiple files at the same time; for instance, while iterating through the many elements, test "if this element is of the type A, it goes into file A.xml; if it is of type B, it goes into B.xml..." and so on.

xsl:result-document doesn't work that way. The reason is that the order of items in the output files would then depend on the order of evaluation of instructions in the "loop" (which isn't really a loop at all, it's a mapping function). Writing documents is thus just like writing multiple elements: you have to structure your code according to the output you are producing, not the input you are reading.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference