[Zope-dev] ANNOUNCE: Xron spins off from ZScheduler

[Loren Stafford]

The copyright to ZScheduler belongs to my former employer, who, as far as I
know do not plan continued development.

I have created a derivitive product, Xron, in accord with the GPL licence of
ZScheduler, and my future development effort will go into Xron. The
copyright for the changes to ZScheduler which are implemented in Xron will
belong to me (tho I really can't see any advantage to owning copyright for
an open source product).

"Xron" is pronouced as you would pronounce the "chron" in "chronometer" or
the "cron" in Unix. The first version of Xron is alpha release 0.0.8 as it
is derived from ZScheduler version 0.0.7.

The following is from the CHANGES.txt document:

Xron Version 0.0.8 Date: 2000/07/28

  1. Derived Xron product from ZScheduler product Version 0.0.7 in accord
with license.

  2. Changed the Trigger tab method so it won't deadlock when Zope is in
single thread mode.

  3. Changed several names to improve consistency and comprehensibility.
  The most significant API change is that the class for Sheduled Event is
now 'XronDTMLMethod',
  its add method 'manage_addXronDTMLMethod', and its meta-type 'Xron DTML
Method'
  This change anticipates the possibility of implementing other kinds of
scheduled methods
  (Xron Python Method, for example).

  4. Added 'meta_type' to the Schedule catalog.
  Derived classes which have their own meta-type will be identifiable in the
Schedule listing.
  You will have to delete your old catalog, so that Xron can create a new
one.

  5. Simpified the manage_catalogView for the Schedule.

  6. Encapsulated the remote procedure call interface, so that you can
conveniently replace it.
  The existing RPC interface is Client.py, which uses the HTTP protocol.
  You may want to provide a different RPC interface that uses, for example,
the HTTPS protocol.


Upgrading from ZScheduler:

  No automatic upgrade path has been provided.
  Before installing Xron, you should delete any subclasses based on ZEvent
  (though you may want to save any significant text for pasting into new
Xron methods),
  delete the Schedule object, then delete the ZScheduler product.
  You may have to change some identifiers to their Xron synonyms.
  Then delete the ZEvents.

Known Problems:

  1. For Zope version 2.2.0 you will have to patch Client.py.
  See collector item #1480 http://classic.zope.org:8080/Collector/1480/view

-- Loren