plugin / intra process communication system

[Diez B. Roggisch]

Am 14.02.10 13:05, schrieb Florian Ludwig:
> On Sun, 2010-02-14 at 10:16 +0100, Paul Kölle wrote:
>> Am 13.02.2010 10:50, schrieb Florian Ludwig:
>>> Hi,
>>>
>>> I'm looking for a module/plugin/intra-process-communication/hook system
>>> for python. Maybe someone here could point me to some project I missed
>>> or might have some good ideas if I end up implementing it myself.
>>>
>>> [...]
>>>
>>> The plugins you wrote probably import them from the wiki module directly
>>> which means your blog would depend on the wiki. (?!) So where to put the
>>> interface/[...] definition that is imported by those plugins? Create a
>>> package/module just containing the interface? This really get
>>> troublesome if different people wrote the wiki, the blog and another
>>> third one a plugin.
>
>> If you are talking about code sharing you can move the common code out
>> of your applications in a seperate namespace. If you follow the model
>> trac is using you would install a module/package/egg with the basic
>> functionality of the pluginsystem (i.e. what's in core.py and env.py +
>> logging and whatever you think is necessary).
>
>> All shared code like your auth-plugins would go in a common plugin
>> directory to which you can refer via PYTHONPATH.
>
> You're right, its about code sharing/reusing - should have said it more
> clearly. What I am looking for is the pluginsystem that makes this easy.
> Here there problem with the trac (and other plugin systems I've seen)
> approach:
>
> You need to define something like:
> |
> | class IAuthPlugin(Interface): [...]
> |
> in your blog software.

Why? Any reason you can't define it in a separate package the 
blog-software depends on, as well as your wiki?


And then of course, this is not really needed. In Python, behavior 
counts, not type-information. So you can get away without any explicit 
declared interface. You might chose to not do that, for aestetic 
reasons, or better documentation. But you aren't forced.

diez