Re: Schema provider/CA lookup status

whit morriss-2 wrote:
> 
> cool...will we still be able to register a schema by interface? wouldn't 
> the classgen stuff go inside the adapter function/class?
> 
> so if you didn't need the slight overhead, you could avoid it? or will 
> all schema require this?
> 
> I need to look at the code but anything you could do in Schema() should 
> be able to be done in an adapter.  hopefully Schema() will go away 
> eventually...
> 

I don't quite see the win in this. Schema() (well, the aq-wrapping is a bit
annoying) is the canonical way of getting the schema of an AT object, and is
part of the IBaseObject contract.

AT as it is now won't work unless ClassGen has had a chance to generate
methods for every field in the schema. I'm not sure how wide-spread this
assumption is, but there are many things doing a getattr(context,
field.accessor) for example - assuming those methods exist. Without it, the
checks fo whether a field is writable fail, meaning that they don't show up
in base_edit.

The need to re-run ClassGen's method generation is general and ought to be
in the framework, not a requirement of each adapter. If you look at
http://svn.plone.org/svn/collective/company/trunk/content/schema.py you'll
see how I use a slightly different pattern, looking up an ISchemaExtender
that's allowed to extend the schema.

Getting rid of the ClassGen assumption entirely is likely to be fairly
invasive, since it's such a fundamental part of the interface to AT objects.
OTOH, the pattern in the file above is fairly non-invasive and seems to work
well.

Martin
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View this message in context: http://www.nabble.com/Schema-provider-CA-lookup-status-tf1921614.html#a5578095
Sent from the Archetypes - devel forum at Nabble.com.


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