lets say you have the resultant transformation produced by
http://localhost/transform.php
which produces
<?xml version="1.0"?>
<test><?php echo "test" ?></test>


then to reprocess it, just call it from another PHP script like so
include_once "http://localhost/transform.php";


Of course this requires short open tags to be off. But it is simpler
than anything else. You can use this rechnique for any sort of
processing pipeline but be careful when getting a script to recursively
call itself :)


I haven't tried this myself but I think I read somehwere that protocol
identifiers (like "http://") are supported by include statements. It
should work.