[Zope3-dev] Component install script

[Jim Fulton]

Stephan Richter wrote:
> On Thursday 17 March 2005 10:14, Julien Anguenot wrote:
> 
>>What whould be the proper mecanism for a zope3 component installation
>>script ? (like the external methods we are using with the CMF)
>>
>>Registering a subscriber on the IDataBaseOpenedEvent seems a little bit
>>violent to me ;);)
> 
> 
> Subscribing to IDataBaseOpenedEvent is exactely the right thing to do. The 
> reason the event is there is to use it :-)

Actually, we've discovered that that's not the right thing to do.

If you *do* go this route, you should subscribe to a
IDatabaseOpenedWithRootEvent so that you know that the root
object has already been created and so that you don't rely
on event ordering.

The better way to do this is to define a generations schema manager with
an installation script. That way, you can also update your installation
in a controlled way.

See: http://svn.zope.org/Zope3/trunk/src/zope/app/generations/README.txt?view=markup

This all assumes that you want the installation done globally.

If you want installation for each site, then it would probably be better
to install event subscribers for adding sites.

Jim

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