Christoph Haas wrote:
> On Sun, Sep 25, 2005 at 11:33:03PM -0400, Jeff Schwab wrote:
>
>>I recently came up against this exact problem. My preference is to have
>>the plugin writer call a method to register the plugins, as this allows
>>him the most control. Something along these lines:
>>
>> class A_plugin(Plugin):
>> ...
>>
>> class Another_plugin(Plugin):
>> ...
>>
>> register( A_plugin )
>> register( Another_plugin, optional_custom_registration_parameters )
>
>
> I like the idea. And "supybot" seems to do just that. What would the
> "def register:" do? Maintain a global list of registered plugins?
> I didn't like the idea of having global variables. Or would register
> be a method of some "main" class? How would I access that?
The registry clearly has to be shared between modules, so I think it's
best to make it a module-level variable. In the simple-minded code
below, I've stored it in the "plugins" module. A better choice might be
the module that defines your plugins' common base class, if they have one.
# BEGIN framework.py
if __name__ == "__main__":
import plugins
print plugins.plugin_registry
# END framework.py
# BEGIN plugins.py
# Define some plugins.
class A_plugin(object):
def __init__(self):
print "A_plugin()"
class Another_plugin(object):
def __init__(self):
print "Another_plugin()"
# Register the plugins.
import registry
plugin_registry = registry.Registry()
plugin_registry.register(A_plugin)
plugin_registry.register(Another_plugin)
# END plugins.py
# BEGIN registry.py
class Registry(object):
"Each instance may be used to store a set of objects."
def __init__(self):
"Initialize an empty registry."
self.registered_objects = set()
def register(self, o):
"Add an object to the registry."
self.registered_objects.add(o)
def __repr__(self):
return "Registry Contents:\n\t" + \
"\n\t".join(repr(o) for o in self.registered_objects)
# END registry.py
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