Re: [Docutils-users] more-universal links?

David Goodger wrote:
> [Robert Brewer]
>  > I would just prefer to show the .txt file explicitly in the source
>  > text and add some other decoration that expresses it is rewritable
>  > by the backend.
> 
> That may be asking too much.

what about rules?

i think about this:

.. role:: link(rewrite)
     :transform: .txt|.html

and then to use it:

::

     for more information see :link:`README.txt`


it would be useful if it supported an additional option
     :format: html
so that separate rules for each format can be defined.
(like the "raw" role)

below is a simple implementation of "rewrite".
an improved version could allow regexps and not just replace the end of 
the string (the one below does not support internal links like 
README.txt#section-one

a more generic "rewrite", for not just links, could be useful for other 
things too.. maybe...

chris


#-------------- to be placed in a writer or rules.py ---
from docutils.nodes import whitespace_normalize_name
from docutils.parsers.rst import roles

def role_rewrite(name, rawtext, text, lineno, inliner,
             options={}, content=[]):
     if not options.has_key('transform'):
         msg = inliner.reporter.error(
           'No transform is associated with this role: "%s".\n'
           'The "rewrite" role cannot be used directly.\n'
           'Instead, use the "role" directive to create a new role with '
           'an associated format.' % role, line=lineno)
         prb = inliner.problematic(rawtext, rawtext, msg)
         return [prb], [msg]
     if '|' not in options['transform']:
         msg = inliner.reporter.error(
             'The transform is invalid with this role: "%s".\n'
             'e.g. ".txt|.html".' % role, line=lineno)
         prb = inliner.problematic(rawtext, rawtext, msg)
         return [prb], [msg]
     rin, rout = options['transform'].split('|')
     if text.endswith(rin):
         text = text[:-len(rin)] + rout
     node = nodes.reference(rawtext, utils.unescape(text), 
name=whitespace_normalize_name(text))
     return [node], []

role_rewrite.options = {
     'transform': directives.unchanged,
     'format': directives.unchanged
}

roles.register_local_role('rewrite', role_rewrite)

#------------------------

cr