[Zope3-Users] Scheduler package usage

[Thierry Florac]

  Hi,

I'm trying to use the "scheduler" package available from Zope3's CVS to
handle a set of regular and automatic tasks in my Zope-3.3 setup (using
Twisted).

My code is as follows :

manager.py::

        def fire_alerts():
            # Handle exception because alert can be fired
            # before utilities are registered
            try:
                query = zapi.getUtility(IQuery)
                query_index = ('Catalog','alert')
                query_param = Le(query_index, datetime.now())
                alerts = query.searchResults(query_param)
                for alert in alerts:
                    alert.alert()
            except:
                print " >>> AlertsManager : an error occurred !"
        
        
        class AlertsManager(CronTask):
            """Alerts are defined as CronTasks launched every 5
        minutes"""
            
            implements(IAlertsManager)
            
            def __init__(self, *args, **kw):
                super(AlertsManager,self).__init__(callable=fire_alerts,
        \
        
        minute=(5,10,15,20,25,30,35,40,45,46,47,48,49,50,55,))
        
configure.zcml::

    <utility
        name="AlertsManager"
        factory=".manager.AlertsManager"
        provides="scheduler.interfaces.ITask" />


Adding a few "prints" show that AlertsManager is well instanciated and
that the defined alert is called only once if the "start" method is
overriden with "now=True" ; but after that, even if the alert seems to
be rescheduled at the correct time, the corresponding task is not called
anymore.

Another last question : are transaction handled "normally" and
"transparently" as are other Zope3 transactions, or should I have to
handle them specifically when the requested task can modify data ??

Any help or advise would be greatly appreciated...

  Thierry Florac
-- 
  Chef de projet intranet/internet
  Office National des Forêts - Département Informatique
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  75570 PARIS Cedex 12
  Mél : thierry.florac at onf.fr
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