[Zope3-dev] Re: a new zcml directive?

[Jim Fulton]

Martijn Faassen wrote:
...
> I just tried to write AnnotationAdapter. Unfortunately, I haven't gotten 
> very far yet, as it turns out I need to understand the internals of the 
> implementation of the zope:adapter ZCML statement.

No, you don't.

> zope:adapter has a bunch of automation to look for the interface of 
> something and what it adapts on the factory. This works if the factory 
> is the class itself, but in this case, the factory is a class which has 
> instances which can provide an instance of the annotation class when 
> called.

This may not be documented as well as it should be, but not for lack of
trying.

1. You can always provide the interface provided by an adapter
    when you register it.

2. If a factory declares that it implements a single interface,
    then you can omit the interface when registering the adapter.

    If a factory is a class, it typically declares that it implements
    an interface via the implements call in the class statement.

    If a factory is not a class, and if it allows attributes to be
    set on it, then the interface.implementor function can be used to make
    declarations for it.  This is documeted in zope/interfaces/README.txt
    and zope/component/README.txt.

Jim



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