Re: Options for making AT schemas more adaptive
"Martin Aspeli" <[email protected]>
| Newsgroups | gmane.comp.web.zope.plone.archetypes.devel |
|---|---|
| Message-ID | <[email protected]> |
On Tue, 02 May 2006 19:07:47 +0100, Rob Miller <ra-UE+B0n23d/[email protected]> wrote: > the first step in this process, i'd say, would be to define > ISchemaConsumer and ISchemaProvider interfaces. BaseObject, and > therefore all derived types, would implement ISchemaConsumer. the > BaseObject Schema() method would call ISchemaProvider(self) to retrieve > an adapter that would actually return the schema object. Out of interest, is the ISchemaConsumer any more than a marker? Also, I think this is pretty much what whit just did ... and see my latest reply to his post. > the default implementation of this adapter would do exactly what it does > now, simply accessing self.schema. we'll want to deprecate direct > schema attribute access... not quite sure how to achieve that; where do > we put the deprecation message? Make a property with an accessor method that spits a warning, perhaps? > anyway, now we've got more flexibility. adapters from more specific > interfaces to ISchemaProvider can be implemented that will override the > schema retrieval behaviour. ATSENG support can then be gained via a > marker interface, for instance, instead of the mix-in currently > required. also, the default adapter could be easily overridden if you > want to change global schema behaviour. we can also require that > adapters to ISchemaProvider fire events to allow for subscribers to > impact the process. As I mentioned to whit, I think there's some more thought to be had around having multiple schemas aggregated by this mechanism. E.g. a site policy could install some fields, a tagging product could install its own fields, and the type could have a few of its own. We could get all adapters to ISchemaProvider from self, of course, but we'd then also have to have some component responsible for sorting and merging the schemata. Martin -- "You can just adapt yourself out of it..." // Archipelago sprint 26/04/2006 ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642