Oh dear. Products in Plone that don’t care to uninstall themselves at all when removed. One such product that comes to mind is ZipFileTransport.

I could go into depth all day about its failure to uninstall, but in specific, it’s this line of code in its setupHandlers.py file that kills me:

sm.registerUtility(ZipFileTransportUtility('zipfiletransport'), IZipFileTransportUtility)

Now, where’s the unregisterUtility called? Nowhere, unfortunately. So when one tries to go and install/uninstall/reinstall/do certain things on the site, you get a nasty failure message about trying to unpickle a python object:

2009-04-23 10:19:19 ERROR Zope.SiteErrorLog http://localhost:8080/eresearch/portal_quickinstaller/uninstallProductsTraceback (innermost last):
Module ZPublisher.Publish, line 125, in publish
Module Zope2.App.startup, line 238, in commit
Module transaction._manager, line 96, in commit
Module transaction._transaction, line 395, in commit
Module transaction._transaction, line 495, in _commitResources
Module ZODB.Connection, line 510, in commit
Module ZODB.Connection, line 555, in _commit
Module ZODB.Connection, line 582, in _store_objects
Module ZODB.serialize, line 407, in serialize
Module ZODB.serialize, line 416, in _dump
PicklingError: Can't pickle: import of module Products.ZipFileTransport.utilities.interfaces failed

Solution?

Okay, I found the unregisterUtility function in zope.component, and it can be accessed by something like this (ipython session, of course): (You’ll need at least the ZFT parts below present to import them).

from zope.app.component.hooks import setSite
from zope.component import getSiteManager
from Products.ZipFileTransport.utilities.interfaces import IZipFileTransportUtility
from Products.ZipFileTransport.utilities.utils import ZipFileTransportUtility
setSite(portal)
sm = getSiteManager()
sm.unregisterUtility(component=None, provided=IZipFileTransportUtility)

#Even though unregister happened, it probably said it worked but left crap around.
#Let's clean it up

#This intclass variable might not be right.  It's going to be the key present below,
#so you can always find the right InterfaceClass manually and set it accordingly.
intclass = IZipFileTransportUtility
del sm.utilities._adapters[0][intclass]
del sm.utilities._subscribers[0][intclass]

#From here, search for 'Zip' to see if it's gone
#Each should return -1.  If not, you've done something wrong!
str(sm.utilities._adapters[0]).find('Zip')
str(sm.utilities._subscribers[0]).find('Zip')
str(sm.utilities.__bases__[0].__dict__).find('Zip')

And thus ends the tyranny of ZipFileTransport.

• Filed under IT, Work
• Tags: plone, problem, products, zip
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