Getting Dates with Plone: Connecting People with Events (Aaron VanDerlip)

An overview of Plone4ArtistsCalendar, targeted at integrators.

Plone4ArtistsCalendar was a big monolith at the beginning, but it has be refactored to have a more modular design:

  • dateable.chronos: the user interface (provides calendar views, calls event providers, reusable outside p4a)
  • datable.kalends: the interfaces
  • p4a.plonecalendar: extention of calendar framework (register folders and topic types to implement IPossibleCalendar, hooks for import/export of iCal feeds)
  • p4a.ploneevents: extension of event type (implements dateable.kalends.IRecurringEvent, uses schemaextender to add Recurrence support)
  • p4a.subtypes: provide a way for adding marker interfaces through the Plone UI.

After installing Plone4ArtistsCalendar, folders + topics can be marked as calendar subtype. And since collections can also be subtyped to be a calendar, one can show only the events belonging to the category X.

Plone events do not support recurrence. With Plone4ArtistsCalendar you can have an event recurring e.g. every day, instead of having just a single start and end date. A practical example, you can add the Plone Conference event and have that start at 9 AM and end at 5 PM each day for October 8 - 10, instead of having a single event starting October 8th, 9 AM and end at October 10th at 5 PM.

Plone4ArtistsCalendar can also import either iCal files from file system or from a URL. To do this, add a folder, mark it as being a calendendar and you can instantly import the iCal. Importing the same iCal file, events are not duplicated since a hash of the event is stored. As long as the event hasn’t changed, the event is left alone. Changes in the event could result in duplicates however. Note that the events are not synchronised when you import from an URL; importing is only done once. (Unless you manually import it again obviously.)

By having the ICalendarEnhanced interface, it’s quite easy to e.g. add a viewlet to the calendar views. There is no need to subtype anything. A piece of ZCML and a page template could be enough to do the job. (Depending on the complexity of the content of the viewlet obviously.)