In ye olde barbaric days, one thing was handy: templates and python scripts reloaded just fine in debug mode and a refresh.txt in your product went a long way to not having to restart your zope too often.

Zcml only loads on startup, so a change there means a zope restart, probably nothing to be done about that. But I seem to be restarting zope for just about every single little python change.

So I asked around on the mailinglist last month: on the current strategies for preventing too many zope restarts during development?  I was bound to miss a few tips and tricks otherwise :-) So here's a summary.

• Raphael Ritz had the shortest answer: TDD. Yes, test driven development is   core to preventing restarts as you minimize the amount of in-browser testing   and trying.
• I've tried RefreshNG and that seemed to   work reasonably OK. Not all the time, but it helped. Andreas Jung rightfully   mentioned it. I didn't install it in the last projects I worked on: time for   a more focused test later this month.
• Kai points towards my restart-preventing product of   choice: pyflakes   . The best python syntax checker available! Missing imports, = instead of   ==, head-slapping stuff like that. Catch it before restarting zope :-)
• Kai again: PDBDebugMode can help you to find a solution exactly at the point   of error. It does actually prevent try-error-retry restarts and is a joy to   use.

Martin Aspeli provided the full list of rules on what requires a restart:

• If you are in non-debug-mode, a restart is required for any change at all,   more or less.
• If you are in debug mode, any .pt file changed anywhere does not require a   restart
• If you are in debug mode, any Zope 3 browser resource (accessed with the   ++resource++ namespace) can be changed without a restart
• GenericSetup XML files and Install.py files (unless there's also an   Install.pyc file, but you can delete it while Zope is running) created in   Extensions for use by portal_quickinstaller can be changed without a   restart. However, a custom setuphandler in a normal .py file cannot be   change.d
• Anything in a skin layer will not require a restart - that includes Script   (Python)'s.
• Any other kind of .py file change will require a restart
• Any ZCML change will require a restart

Those plone mailing lists sure are great :-)

Tags: plone