[Docutils-users] Using reporter observer pattern in a writer

[Dave K. <dku...@re...>]

While I was working on implementing a writer for Docutils ...  The
Writer/Translator design seems very powerful and has been very
useful to me, especially as I learn and understand it better.

So, I have a question (or two) ...

The translator (in my case, a subclass of nodes.GenericNodeVisitor)
has a document attribute, which has a reporter attribute.  The
reporter supports 'a modified form of the "Observer" pattern'. 
When I attach an observer (a method), I find that it receives as
its argument an instance of class nodes.system_message.  How do I
use this system_message object?

- One thing that I want to be able to use in my observer method is
  the current node.  I can't find it.  Is it in the system_message
  object someplace?

- The system_message object has a tagname attribute.  But, that
  seems to always return "system_message".  I was hoping for the
  name of the current node.

- How would I write an observer method that prints out just the
  name of the current node?  Ditto for the name of the current
  visit_/depart_ method.  The system_message object has a string
  representation that contains this information, and I suppose I
  could parse that.  But, I suspect that is not the way this object
  was intended to be used.

This observer and system_message thing seems very ingenious.  It
looks like a lot of time and attention was put into its design.  But,
it's quite opaque to me so far.  Is there someplace I could look
for hints and suggestions?

Thanks for help.

Dave

-- 
Dave Kuhlman
http://www.rexx.com/~dkuhlman