[Twisted-Python] twisted plugins

[Gabriel Rossetti]

Hello,

I tried creating some test plugins using the plugin howto on the twisted 
website. I did as shown, I added the plugins dir to the PYTHONPATH and 
tested it. The problem is I get nothing back when calling 
getPlugins(IMyInterface).  Here is some code :

----------------------------------------------------------------------------------------------

    from zope.interface import Interface

    class IHelloWorld(Interface):
        """
        A simple test plugin that displays "Hello world"
        """
       
        def display():
            """
            Displays on stdout "Hello world" in a language chosen by the
    programmer
            """

----------------------------------------------------------------------------------------------

    from twisted.plugin import IPlugin
    from zope.interface import implements
    from interfaces import ihelloworld

    class EnglishHelloWorld(object):
       
        implements(IPlugin, ihelloworld.IHelloWorld)

        def display(self):
            """
            Displays on stdout "Hello world" in English
            """
            print "Hello world!"

---------------------------------------------------------------------------------------------- 


    from twisted.plugin import getPlugins
    from twisted.plugin import IPlugin
    from interfaces import ihelloworld

    def displayHelloWorld():
       
        for h in getPlugins(ihelloworld.IHelloWorld):
            h().display()
           
    if(__name__ == "__main__"):
        displayHelloWorld()

----------------------------------------------------------------------------------------------

I tried running in debug mode to see what happens, but I don't get it, 
in the getPlugins() code, it does this :

    allDropins = getCache(package)

and in this dict I see my plugins, but their inner "plugin" member is an 
empty list. I looked at the code of some of the examples, they used 
"classProvides()" and not "implements()", so I tried that :

----------------------------------------------------------------------------------------------

    from twisted.plugin import IPlugin
    from zope.interface import implements
    from zope.interface import classProvides
    from interfaces import ihelloworld

    class EnglishHelloWorld(object):
       
        classProvides(IPlugin, ihelloworld.IHelloWorld)

        def display(self):
            """
            Displays on stdout "Hello world" in English
            """
            print "Hello world!"

----------------------------------------------------------------------------------------------

which works, is the doc out of sync with the current code or did I do 
something wrong? Another question, it's not really very practical to 
have to iterate all the plugins and I guess test to see which one is 
which, is there a better way of doing it?

Thank you,
Gabriel