Post publication hook? Hook for cleanup operations after request finished

Plone Support Add-on Development
1

Is there a replacement for the plone.postpublicationhook in Plone 5.2/Zope 4?

Scenario: I generated a ZIP file within a browser view which is delivered back to the client as response.
The generated temporary ZIP file should be deleted after delivery. The ZIP file is returned through a filestream_iterator. One option might be to create a custom iterator and hook the deletion into its __del__() implementation but this appears too ugly to me. Are there any other post publication hooks available in Zope 4?

2

The plone.postpublicationhook readme says: "The IPubBeforeCommit event is equivalent to the IAfterPublicationEvent".
Here's a bunch of them: https://github.com/zopefoundation/Zope/blob/master/src/ZPublisher/pubevents.py

https://github.com/zopefoundation/Zope/blob/8e6b9336d109e97f6e7915b4a18c57c278afcd1d/src/ZPublisher/interfaces.py#L23-L28 might be an option. Keep in mind that it will fire multiple times if requests are retried.

1 Like
3

There are the ZPublisher.interfaces.IPubEnd events.

For request related cleanup, BaseRequest._hold is often used. You could for example represent your zip file as a TemporaryFile and hold it via _hold until the request object is deleted.

4

According to the Python docs if you use tempfile.TemporaryFile then the file is "destroyed as soon as it is closed (including an implicit close when the object is garbage collected)".

I would try that.

5

May can anyone of you point me to a code that works out of the box?
I tried this but the event never fires:

from Products.CMFCore.interfaces import ISiteRoot
from ZPublisher.pubevents import IPubBeforeCommit

def pubend(**kwargs):
    print(kwargs)

gsm = zope.component.getGlobalSiteManager()
gsm.registerHandler(pubend, (ISiteRoot, IPubBeforeCommit))

I also tried ZPublisher.interfaces.IPubEnd which does not work either.

What works on the other hand is this:

from Products.CMFCore.interfaces import ISiteRoot
from zope.traversing.interfaces import IBeforeTraverseEvent
gsm = zope.component.getGlobalSiteManager()
gsm.registerHandler(hookTraverse, (ISiteRoot, IBeforeTraverseEvent))

But in my case I need a hook just before the response to the browser goes out. And then inside the hook I need access to the request and the response.

It can not see where there was an explicit example in this thread.