[Zope3-Users] Re: Still trying to connect to ZODB from external

[Jürgen Kartnaller]

Florian,
you should definitely have a look at the package zc.async and/or 
lovely.remotetask.
lovely.remotetask is in heavy use in our applications and contains a 
scheduler like the scheduler provided in zope.

Jürgen

Florian Lindner wrote:
> Hello,
> I have a function called by a scheduler. Since it operates outside of Zope 
> context I need to create a connection to the ZODB in order to call a utility:
> 
>     db = getUtility(ZODB.interfaces.IDatabase)
>     conn = db.open()
>     root = conn.root().data['Application']
>    
>     zope.app.component.hooks.setSite(root["cs"])
>     
>     utils = getUtilitiesFor(INewsfeed)
>     for i in utils:
>         print "Utility called:", i[0]
>         i[1].sendNotification()
>    
>     conn.close()
> 
> This produces errors like:
> 
> Unhandled error in Deferred:
> Traceback (most recent call last):
>   File "/home/florian/Zope3/src/twisted/internet/posixbase.py", line 220, in 
> run
>     self.mainLoop()
>   File "/home/florian/Zope3/src/twisted/internet/posixbase.py", line 228, in 
> mainLoop
>     self.runUntilCurrent()
>   File "/home/florian/Zope3/src/twisted/internet/base.py", line 561, in 
> runUntilCurrent
>     call.func(*call.args, **call.kw)
>   File "/home/florian/Zope3/src/twisted/internet/task.py", line 108, in 
> __call__
>     d = defer.maybeDeferred(self.f, *self.a, **self.kw)
> --- <exception caught here> ---
>   File "/home/florian/Zope3/src/twisted/internet/defer.py", line 107, in 
> maybeDeferred
>     result = f(*args, **kw)
>   File "/home/florian/Desktop/zope/lib/python/CS/centershock/centershock.py", 
> line 34, in releaseRefreshEvent
>     conn.close()
>   File "/home/florian/Zope3/src/ZODB/Connection.py", line 268, in close
>     raise ConnectionStateError("Cannot close a connection joined to "
> ZODB.POSException.ConnectionStateError: Cannot close a connection joined to a 
> transaction
> 
> What is the right way to do it?
> 
> Thanks,
> 
> Florian