collective.timedevents 0.2.1

Plone/Zope time based event mechanism

Overview

This is a developer level product. This product is indended to replace Products.TickingMachine with more robust Zope 3 codebase.

Usage

1. Install collective.timedevents

Add the following to your buildout.cfg:

eggs =
        ...
        collective.timedevents

Add clock server to tick timedevents subscribers - use your Plone instance name:

[instance]
...
zope-conf-additional =
        <clock-server>
            method /mysite/@@tick
            period 90
        user admin
            password adminpassword
            host localhost
        </clock-server>

2. Add collective.timedevents.interfaces.ITickEvent subscribers to your product ZCML declarations.

   Example:

   <configure
   xmlns="http://namespaces.zope.org/zope"
   xmlns:browser="http://namespaces.zope.org/browser"
   i18n_domain="harvinaiset.app">
   
                <subscriber
                      handler="myproduct.tickers.on_tick"
                      for="collective.timedevents.intefaces.ITickEvent"
                    />
   
   </configure>
   

3. Configure your event handler to react after certain period has expired:

   from zope.app.component.hooks import getSite
   
   def on_tick(event):
       """ Do something after one hour has elapsed """
       interval_in_days = 1.0 / 24.0 # One hour, floating point
       context = site.my_magic_context # Persistent object which stores our timing data
       if event.last_tick > context.last_action + interval_in_days: # Check whether enough time has elaped
           do_stuff()
           context.last_action = event.last_tick # Store when we last time did something
   

Other

All ticking code is executed under admin privileges. Tick period is 300 seconds by default. This can be controlled in views.py. Ticks are logged by events.tick_logger defined in configure.zcml.

The product is loosely connected to Plone, but can be used standalone with little modifications.

Quality assurance

This product fills the following quality criteria:

• Unit tests provided
• Good documentation provided
• Commented code
• PyPi eggs provided

Future

Cron like "on day/hour/minute X" like subscribers could be added.

Author

• Mikko Ohtamaa
• Quintagroup
• The orignal concept and code was created by Tomasz J. Kotarba