############################################################################
#
# Copyright (c) 2001, 2002 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
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"""
Component and Component Architecture Interfaces
The `IComponentArchitecture` and `IComponentRegistrationConvenience` interfaces
are provided by `zope.component` directly.
"""
from zope.interface import Attribute
from zope.interface import Interface
# pylint:disable=inherit-non-class,no-self-argument,no-method-argument
[docs]class IComponentArchitecture(Interface):
"""The Component Architecture is defined by two key components: Adapters
and Utiltities. Both are managed by site managers. All other components
build on top of them.
"""
# Site Manager API
def getGlobalSiteManager():
"""Return the global site manager.
This function should never fail and always return an object that
provides `zope.interface.interfaces.IComponents`.
"""
def getSiteManager(context=None):
"""Get the nearest site manager in the given context.
If *context* is `None`, return the global site manager.
If the *context* is not `None`, it is expected that an adapter
from the *context* to
:mod:`zope.interface.interfaces.IComponentLookup` can be
found. If no adapter is found, a
`~zope.interface.interfaces.ComponentLookupError` is raised.
"""
# Utility API
def getUtility(interface, name='', context=None):
"""Get the utility that provides interface
Returns the nearest utility to the context that implements the
specified interface. If one is not found, raises
`~zope.interface.interfaces.ComponentLookupError`.
"""
def queryUtility(interface, name='', default=None, context=None):
"""Look for the utility that provides *interface*
Returns the nearest utility to the *context* that implements the
specified interface. If one is not found, returns *default*.
"""
def queryNextUtility(context, interface, name='', default=None):
"""Query for the next available utility.
Find the next available utility providing *interface* and having the
specified name. If no utility was found, return the specified *default*
value.
"""
def getNextUtility(context, interface, name=''):
"""Get the next available utility.
If no utility was found, a `~zope.interface.interfaces.ComponentLookupError` is raised.
"""
def getUtilitiesFor(interface, context=None):
"""Return the utilities that provide an interface
An iterable of utility name-value pairs is returned.
"""
def getAllUtilitiesRegisteredFor(interface, context=None):
"""Return all registered utilities for an interface
This includes overridden utilities.
An iterable of utility instances is returned. No names are
returned.
"""
# Adapter API
def getAdapter(object,
interface=Interface, name=u'',
context=None):
"""Get a named adapter to an interface for an object
Returns an adapter that can adapt object to interface. If a matching
adapter cannot be found, raises `~zope.interface.interfaces.ComponentLookupError`.
"""
def getAdapterInContext(object, interface, context):
"""Get a special adapter to an interface for an object
.. note::
This method should only be used if a custom context
needs to be provided to provide custom component
lookup. Otherwise, call the interface, as in::
interface(object)
Returns an adapter that can adapt object to interface. If a
matching adapter cannot be found, raises
`~zope.interface.interfaces.ComponentLookupError`.
If the object has a ``__conform__`` method, this method will be
called with the requested interface. If the method returns a
non-None value, that value will be returned. Otherwise, if the
object already implements the interface, the object will be
returned.
"""
def getMultiAdapter(objects,
interface=Interface, name='',
context=None):
"""Look for a multi-adapter to an *interface* for an *objects*
Returns a multi-adapter that can adapt *objects* to *interface*.
If a matching adapter cannot be found, raises
`~zope.interface.interfaces.ComponentLookupError`.
The name consisting of an empty string is reserved for unnamed
adapters. The unnamed adapter methods will often call the
named adapter methods with an empty string for a name.
"""
def queryAdapter(object, interface=Interface, name=u'',
default=None, context=None):
"""Look for a named adapter to an interface for an object
Returns an adapter that can adapt object to interface. If a
matching adapter cannot be found, returns the default.
"""
def queryAdapterInContext(object, interface, context, default=None):
"""
Look for a special adapter to an interface for an object
.. note::
This method should only be used if a custom context
needs to be provided to provide custom component lookup.
Otherwise, call the interface, as in::
interface(object, default)
Returns an adapter that can adapt object to interface. If a
matching adapter cannot be found, returns the default.
If the object has a ``__conform__`` method, this method will be
called with the requested interface. If the method returns a
non-None value, that value will be returned. Otherwise, if the
object already implements the interface, the object will be
returned.
"""
def queryMultiAdapter(objects,
interface=Interface, name=u'',
default=None,
context=None):
"""Look for a multi-adapter to an interface for objects
Returns a multi-adapter that can adapt objects to interface. If a
matching adapter cannot be found, returns the default.
The name consisting of an empty string is reserved for unnamed
adapters. The unnamed adapter methods will often call the
named adapter methods with an empty string for a name.
"""
def getAdapters(objects, provided, context=None):
"""
Look for all matching adapters to a provided interface for
objects
Return a list of adapters that match. If an adapter is named,
only the most specific adapter of a given name is returned.
"""
def subscribers(required, provided, context=None):
"""Get subscribers
Subscribers are returned that provide the provided interface
and that depend on and are computed from the sequence of
required objects.
"""
def handle(*objects):
"""Call all of the handlers for the given objects
Handlers are subscription adapter factories that don't produce
anything. They do all of their work when called. Handlers are
typically used to handle events.
"""
def adapts(*interfaces):
"""
Declare that a class adapts the given interfaces.
This function can only be used in a class definition.
(TODO, allow classes to be passed as well as interfaces.)
"""
# Factory service
def createObject(factory_name, *args, **kwargs):
"""Create an object using a factory
Finds the named factory in the current site and calls it with
the given arguments. If a matching factory cannot be found
raises `~zope.interface.interfaces.ComponentLookupError`.
Returns the created object.
A context keyword argument can be provided to cause the
factory to be looked up in a location other than the current
site. (Of course, this means that it is impossible to pass a
keyword argument named "context" to the factory.
"""
def getFactoryInterfaces(name, context=None):
"""Get interfaces implemented by a factory
Finds the factory of the given name that is nearest to the
context, and returns the interface or interface tuple that
object instances created by the named factory will implement.
"""
def getFactoriesFor(interface, context=None):
"""Return a tuple (name, factory) of registered factories that
create objects which implement the given interface.
"""
[docs]class IRegistry(Interface):
"""Object that supports component registry
"""
def registrations():
"""Return an iterable of component registrations
"""
[docs]class IComponentRegistrationConvenience(Interface):
"""API for registering components.
.. caution::
This API should only be used from test or
application-setup code. This api shouldn't be used by regular
library modules, as component registration is a configuration
activity.
"""
def provideUtility(component, provides=None, name=u''):
"""Register a utility globally
A utility is registered to provide an interface with a
name. If a component provides only one interface, then the
provides argument can be omitted and the provided interface
will be used. (In this case, provides argument can still be
provided to provide a less specific interface.)
"""
def provideAdapter(factory, adapts=None, provides=None, name=u''):
"""Register an adapter globally
An adapter is registered to provide an interface with a name
for some number of object types. If a factory implements only
one interface, then the provides argument can be omitted and
the provided interface will be used. (In this case, a provides
argument can still be provided to provide a less specific
interface.)
If the factory has an adapts declaration, then the adapts
argument can be omitted and the declaration will be used. (An
adapts argument can be provided to override the declaration.)
"""
def provideSubscriptionAdapter(factory, adapts=None, provides=None):
"""Register a subscription adapter
A subscription adapter is registered to provide an interface
for some number of object types. If a factory implements only
one interface, then the provides argument can be omitted and
the provided interface will be used. (In this case, a provides
argument can still be provided to provide a less specific
interface.)
If the factory has an adapts declaration, then the adapts
argument can be omitted and the declaration will be used. (An
adapts argument can be provided to override the declaration.)
"""
def provideHandler(handler, adapts=None):
"""Register a handler
Handlers are subscription adapter factories that don't produce
anything. They do all of their work when called. Handlers
are typically used to handle events.
If the handler has an adapts declaration, then the adapts
argument can be omitted and the declaration will be used. (An
adapts argument can be provided to override the declaration.)
"""
[docs]class IPossibleSite(Interface):
"""An object that could be a site.
"""
def setSiteManager(sitemanager):
"""Sets the site manager for this object.
"""
def getSiteManager():
"""Returns the site manager contained in this object.
If there isn't a site manager, raise a component lookup.
"""
[docs]class ISite(IPossibleSite):
"""Marker interface to indicate that we have a site"""
[docs]class Misused(Exception):
"""A component is being used (registered) for the wrong interface."""
[docs]class IFactory(Interface):
"""A factory is responsible for creating other components."""
title = Attribute("The factory title.")
description = Attribute("A brief description of the factory.")
def __call__(*args, **kw):
"""Return an instance of the objects we're a factory for."""
def getInterfaces():
"""Get the interfaces implemented by the factory
Return the interface(s), as an instance of Implements, that objects
created by this factory will implement. If the callable's Implements
instance cannot be created, an empty Implements instance is returned.
"""
# Internal helpers
def _inherits_docs(func, iface):
doc = iface[func.__name__].__doc__
# doc can be None if the interpreter drops all docstrings when the
# environment variable PYTHONOPTIMIZE is set 2.
if not doc:
return func
# By adding the ..seealso:: we get a link from our overview page
# to the specific narrative place where the function is described, because
# our overview page uses :noindex:
doc += "\n .. seealso::"
doc += "\n Function `~zope.component.%s` for notes, and " % (func.__name__,)
doc += "\n `~zope.component.interfaces.%s` for the defining interface." % (iface.__name__,)
doc += "\n"
func.__doc__ = doc
return func
def inherits_arch_docs(func):
return _inherits_docs(func, IComponentArchitecture)
def inherits_reg_docs(func):
return _inherits_docs(func, IComponentRegistrationConvenience)