.. Ross Patterson's Blog imported post, created by `$ ./bin/rfc822-to-post` on Mar 15, 2021.

.. meta::
   :description: GenericSetup import hadlers ala ZCML directive handlers
   :keywords: Plone, Zope

.. post:: Aug 23, 2009
   :tags: Plone, Zope
   :author: Ross Patterson
   :redirect:  @@redirect-to-uuid/bfdaab0e00295d8bae163b07317300a9

####
GSML
####

    GenericSetup import hadlers ala ZCML directive handlers

I've gotten so far behind on my blogging, I think it's time to admit
that I'm not behind, I've simply stopped.  :)  In the hopes that I
start up again, I'd like to write a bit about something I wrote a
while ago and still use today: GSML.

The amount of code duplication involved in writing a properly
declaritive GenericSetup import/export handler has always bothered
me.  It seems like most of the duplication involves fairly manually
walking the XML DOM to extract the data needed.  I find this to be
very tedious and error prone.  I think implementing GS import/export
handlers should have *nothing* to do with XML.

ZCML does a great job of allowing directive handlers to be simple
Python functions that know nothing of XML.  I wrote GSML to bring that
separation of concerns to GS import handlers so I could stop writing
DOM walkers.

Currently, GSML lives in `collective.gsqi
<http://pypi.python.org/pypi/collective.gsqi>`_ which is just my
grab bag of patches to GS and portal_quickinstaller I use in my client
work.  Here's a doctest that covers `writing an import handler
<http://dev.plone.org/collective/browser/collective.gsqi/trunk/collective/gsqi/gsml/README.txt>`_
with GSML.  Here's are a `groups import handler
<http://dev.plone.org/collective/browser/collective.gsqi/trunk/collective/gsqi/group/README.txt>`_
and a `references import handler
<http://dev.plone.org/collective/browser/collective.gsqi/trunk/collective/gsqi/refs/meta.py>`_
implemented with GSML.

The current implementation of GSML just wraps the ZCML configuration
engine sufficiently to use it for GS import handlers.  Since ZCML has
never concerned itself with writing ZCML, however, GSML currently
includes no support for export handlers.  This is obviously the most
important TODO.

So please try it out, take a look at it and let me know what you
think.  In particular, if anyone out there has any interest in the
export stuff, either in contributing to it, sprinting on it, advising
on it, or anything else, I'd really like to hear from you.


.. update:: Aug 23, 2009

   Imported from Plone on Mar 15, 2021.  The date for this update is the last
   modified date in Plone.