[Zope3-dev] Re: zope.app.twisted.main?

[Philipp von Weitershausen]

On 5 Feb 2007, at 11:50 , Chris Withers wrote:
> Philipp von Weitershausen wrote:
>> Perhaps there's not a need for that separation in the Zope 3 core  
>> with packages like zope.paste around...
>
> Sorry, you lost me... there's what a need for what seperation?

What I meant: Since is we have things like zope.paste which work fine  
as 3rd party packages already, perhaps the Zope 3 core just needs to  
*support* this separation of server configuration and application  
definition, but doesn't necessarily need to *do* it.

>> Yes, the publication in Zope 3 (which was written at an very early  
>> stage with a lot of Zope 2 background) has a method  
>> "getApplication", but all it does is return the root object. So  
>> let's reflect that name in the utility.
>
> Right, okay, my mistake, that's what I was referring to...
>
>> It just occurred to me that we could make those IRootObjectFactory  
>> things named utilities. Then you cna register as many of them at  
>> the same time and just choose which one you want using a switch  
>> in, say, zope.conf.
>
> Why named? If only so you can register many of them, then I call  
> yagni. Like a unix file system, a zope instance should only have  
> one root :-)

Sure. But the use of named utilities would make it a tad easier  
because you wouldn't need ZCML overrides.

Let's say Zope 3 defines an IRootObjectFactory utility called  
'zope.app.appsetup'. So, a default zope.conf would look like this:

   # root-object-factory -- name of an IRootObjectFactory utility  
that the
   # publication will use to create the root object.
   #
   #  Default: root-object-factory zope.app.appsetup

Now, let's say you want to plug in a custom root object from, say,  
SQL. You'd write your own IRootObjectFactory utility, register it  
like so:

   <utility factory="..." name="my.great.factory" />

and flip the switch in zope.conf:

   root-object-factory my.great.factory

Actual spellings may and probalby should, of course, be subject to  
change.