DOCBOOK-APPS: breaking urls in PDF

I produce PDF from DocBook XML using openjade and pdftex.  I have been 
struggling with the problem of long URLs creating over-long lines.  I have 
been helped by the document "Correcting page make-up problems in SGML-based 
documentation" by Pascal Lo Re (a translation of which is referred to in a 
posting to this group).  This explains how to modify a DSSSL print stylesheet 
to transform ulink elements into JadeTEX commands that can utilise the tex 
url package.:

(element ulink
  (sosofo-append
       (process-children)
        (make formatting-instruction
             data: (string-append
              " (\\url{" (attribute-string (normalize "url")) "}) "))))


 What I eventually get in the PDF is the ulink contents followed by the url 
attribute value in parentheses.  If this latter occurs towards the end of a 
line it can be indeed broken (with no hyphen) - this is good as far as it 
goes.

However what I would like to know is:

i) how can I apply linebreaking instuctions to ulink contents (in addition 
to url attribute value)?

ii) how can I print out the breakable url attribute only if its value differs 
from the value of the ulink element contents (i.e. I would like to emulate 
the behaviour of  ulink within dblink.dsl)


Thanks,

Matthew


--
Matthew Hobbs    +61 2 9036 3004
BioLateral Pty Ltd          http://www.biolateral.com.au/
Level 5, 92 Parramatta Rd, Camperdown, NSW 2050 Australia