zope.interface memo

gistfile1.rst

summary

	provide	implement
descriptor	classProvides moduleProvides	implements implementsOnly
decorator	provider	implementer implementer_only
imperative	directlyProvides alsoProvides noLongerProvides	classImplements classImplementsOnly
predicate	providedBy directlyProvidedBy	implementedBy

• "X provides Y" means the object X can act as the interface Y.
• "X implements Y" means an instance of class X can act as the interface Y.

example

>>> from zope.interface import *
>>> class IFoo(Interface): pass
...
>>> class IBar(Interface): pass
...
>>> class IFooFactory(Interface): pass
...

>>> class C1(object):
...   implements(IFoo)
...   classProvides(IFooFactory)
...

>>> @implementer(IFoo)
... @provider(IFooFactory)
... class C2(object):
...   pass
...

>>> class C3(object):
...   pass
...
>>> classImplements(C3, IFoo)
>>> directlyProvides(C3, IFooFactory)

>>> [i.getName() for i in implementedBy(C1)]
['IFoo']
>>> [i.getName() for i in providedBy(C1)]
['IFooFactory']
>>> [i.getName() for i in providedBy(C1())]
['IFoo']
>>> [i.getName() for i in directlyProvidedBy(C1)]
['IFooFactory']
>>> [i.getName() for i in directlyProvidedBy(C1())]
[]
>>> o = C1()
>>> directlyProvides(o, IBar)
>>> [i.getName() for i in providedBy(o)]
['IBar', 'IFoo']
>>> [i.getName() for i in directlyProvidedBy(o)]
['IBar']

>>> from zope.interface.registry import Components
>>> registry = Components()
>>> registry.registerUtility(C1)
>>> registry.registerUtility(o, IBar)
>>> registry.queryUtility(IFooFactory) is C1
True
>>> registry.queryUtility(IBar) is o
True