############################################################################ # # Copyright (c) 2001, 2002 Zope Corporation 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. # ############################################################################ """Component and Component Architecture Interfaces $Id: interfaces.py 69652 2006-08-18 15:19:59Z philikon $ """ import zope.deferredimport from zope import interface # BBB: Backward-compatibility; 12/05/2004 from bbb.interfaces import * class ComponentLookupError(LookupError): """A component could not be found.""" class Invalid(Exception): """A component doesn't satisfy a promise.""" class Misused(Exception): """A component is being used (registered) for the wrong interface.""" class IObjectEvent(interface.Interface): """An event related to an object. The object that generated this event is not necessarily the object refered to by location. """ object = interface.Attribute("The subject of the event.") class ObjectEvent(object): interface.implements(IObjectEvent) # for repr backward compatibility. In the next release cycle, we'll # provide a testing framework that addresses repr migration. __module__ = 'zope.app.event.objectevent' def __init__(self, object): self.object = object class IComponentArchitecture(interface.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 `IGlobalSiteManager`. """ 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 `IComponentLookup` can be found. If no adapter is found, a `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 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 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.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 ComponentLookupError. If context is None, an application-defined policy is used to choose an appropriate service manager from which to get an 'Adapters' service. If 'context' is not None, context is adapted to IServiceService, and this adapter's 'Adapters' service is used. """ 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 ComponentLookupError. Context is adapted to IServiceService, and this adapter's 'Adapters' service is used. 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.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 ComponentLookupError. If context is None, an application-defined policy is used to choose an appropriate service manager from which to get an 'Adapters' service. If 'context' is not None, context is adapted to IServiceService, and this adapter's 'Adapters' service is used. 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.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. If context is None, an application-defined policy is used to choose an appropriate service manager from which to get an 'Adapters' service. If 'context' is not None, context is adapted to IServiceService, and this adapter's 'Adapters' service is used. """ 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. Context is adapted to IServiceService, and this adapter's 'Adapters' service is used. 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.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. If context is None, an application-defined policy is used to choose an appropriate service manager from which to get an 'Adapters' service. If 'context' is not None, context is adapted to IServiceService, and this adapter's 'Adapters' service is used. 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. If context is None, an application-defined policy is used to choose an appropriate service manager from which to get an 'Adapters' service. If 'context' is not None, context is adapted to IServiceService, and this adapter's 'Adapters' service is used. """ 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. If context is None, an application-defined policy is used to choose an appropriate service manager from which to get an 'Adapters' service. If 'context' is not None, context is adapted to IServiceService, and this adapter's 'Adapters' service is used. """ 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 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. """ class IComponentLookup(interface.Interface): """Component Manager for a Site This object manages the components registered at a particular site. The definition of a site is intentionally vague. """ adapters = interface.Attribute( "Adapter Registry to manage all registered adapters.") utilities = interface.Attribute( "Adapter Registry to manage all registered utilities.") def queryAdapter(object, interface, name=u'', default=None): """Look for a named adapter to an interface for an object If a matching adapter cannot be found, returns the default. """ def getAdapter(object, interface, name=u''): """Look for a named adapter to an interface for an object If a matching adapter cannot be found, a ComponentLookupError is raised. """ def queryMultiAdapter(objects, interface, name=u'', default=None): """Look for a multi-adapter to an interface for multiple objects If a matching adapter cannot be found, returns the default. """ def queryMultiAdapter(objects, interface, name=u''): """Look for a multi-adapter to an interface for multiple objects If a matching adapter cannot be found, a ComponentLookupError is raised. """ def getAdapters(objects, provided): """Look for all matching adapters to a provided interface for objects Return an iterable of name-adapter pairs for adapters that provide the given interface. """ def subscribers(objects, provided): """Get subscribers Subscribers are returned that provide the provided interface and that depend on and are comuted from the sequence of required objects. """ def handle(*objects): """Call handlers for the given objects Handlers registered for the given objects are called. """ def queryUtility(interface, name='', default=None): """Look up a utility that provides an interface. If one is not found, returns default. """ def getUtilitiesFor(interface): """Look up the registered utilities that provide an interface. Returns an iterable of name-utility pairs. """ def getAllUtilitiesRegisteredFor(interface): """Return all registered utilities for an interface This includes overridden utilities. An iterable of utility instances is returned. No names are returned. """ zope.deferredimport.deprecated( "Use IComponentLookup instead. ISiteManager will be removed in 2007.", ISiteManager = "zope.component.interfaces:IComponentLookup", ) class IComponentRegistrationConvenience(interface.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.) 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 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.) 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 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.) 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 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.) 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. """ class IRegistry(interface.Interface): """Object that supports component registry """ def registrations(): """Return an iterable of component registrations """ class IFactory(interface.Interface): """A factory is responsible for creating other components.""" title = interface.Attribute("The factory title.") description = interface.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. """ class IRegistration(interface.Interface): """A registration-information object """ registry = interface.Attribute("The registry having the registration") name = interface.Attribute("The registration name") info = interface.Attribute("""Information about the registration This is information deemed useful to people browsing the configuration of a system. It could, for example, include commentary or information about the source of the configuration. """) class IUtilityRegistration(IRegistration): """Information about the registration of a utility """ component = interface.Attribute("The object registered") provided = interface.Attribute("The interface provided by the component") class _IBaseAdapterRegistration(IRegistration): """Information about the registration of an adapter """ factory = interface.Attribute("The factory used to create adapters") required = interface.Attribute("""The adapted interfaces This is a sequence of interfaces adapters by the registered factory. The factory will be caled with a sequence of objects, as positional arguments, that provide these interfaces. """) provided = interface.Attribute("""The interface provided by the adapters. This interface is implemented by the factory """) class IAdapterRegistration(_IBaseAdapterRegistration): """Information about the registration of an adapter """ class ISubscriptionAdapterRegistration(_IBaseAdapterRegistration): """Information about the registration of a subscription adapter """ class IHandlerRegistration(IRegistration): handler = interface.Attribute("An object called used to handle an event") required = interface.Attribute("""The handled interfaces This is a sequence of interfaces handled by the registered handler. The handler will be caled with a sequence of objects, as positional arguments, that provide these interfaces. """) class IRegistrationEvent(IObjectEvent): """An event that involves a registration""" class RegistrationEvent(ObjectEvent): """There has been a change in a registration """ interface.implements(IRegistrationEvent) def __repr__(self): return "%s event:\n%r" % (self.__class__.__name__, self.object) class IRegistered(IRegistrationEvent): """A component or factory was registered """ class Registered(RegistrationEvent): interface.implements(IRegistered) class IUnregistered(IRegistrationEvent): """A component or factory was registered """ class Unregistered(RegistrationEvent): """A component or factory was registered """ interface.implements(IUnregistered) class IComponentRegistry(interface.Interface): """Register components """ def registerUtility(component, provided=None, name=u'', info=u''): """Register a utility component The registered component provided This is the interface provided by the utility. If the component provides a single interface, then this argument is optional and the component-implemented interface will be used. name The utility name. info An object that can be converted to a string to provide information about the registration. A Registered event is generated with an IUtilityRegistration. """ def unregisterUtility(component=None, provided=None, name=u''): """Unregister a utility A boolean is returned indicating whether the registry was changed. If the given component is None and there is no component registered, or if the given component is not None and is not registered, then the function returns False, otherwise it returns True. component The registered component The given component can be None, in which case any component registered to provide the given provided interface with the given name is unregistered. provided This is the interface provided by the utility. If the component is not None and provides a single interface, then this argument is optional and the component-implemented interface will be used. name The utility name. An UnRegistered event is generated with an IUtilityRegistration. """ def registeredUtilities(): """Return an iterable of IUtilityRegistrations. These registrations describe the current utility registrations in the object. """ def registerAdapter(factory, required=None, provided=None, name=u'', info=u''): """Register an adapter factory Parameters: factory The object used to compute the adapter required This is a sequence of specifications for objects to be adapted. If omitted, then the value of the factory's __component_adapts__ attribute will be used. The __component_adapts__ attribute is usually attribute is normally set in class definitions using adapts function, or for callables using the adapter decorator. If the factory doesn't have a __component_adapts__ adapts attribute, then this argument is required. provided This is the interface provided by the adapter and implemented by the factory. If the factory implements a single interface, then this argument is optional and the factory-implemented interface will be used. name The adapter name. info An object that can be converted to a string to provide information about the registration. A Registered event is generated with an IAdapterRegistration. """ def unregisterAdapter(factory=None, required=None, provided=None, name=u''): """Register an adapter factory A boolean is returned indicating whether the registry was changed. If the given component is None and there is no component registered, or if the given component is not None and is not registered, then the function returns False, otherwise it returns True. Parameters: factory This is the object used to compute the adapter. The factory can be None, in which case any factory registered to implement the given provided interface for the given required specifications with the given name is unregistered. required This is a sequence of specifications for objects to be adapted. If the factory is not None and the required arguments is omitted, then the value of the factory's __component_adapts__ attribute will be used. The __component_adapts__ attribute attribute is normally set in class definitions using adapts function, or for callables using the adapter decorator. If the factory is None or doesn't have a __component_adapts__ adapts attribute, then this argument is required. provided This is the interface provided by the adapter and implemented by the factory. If the factory is not None and implements a single interface, then this argument is optional and the factory-implemented interface will be used. name The adapter name. An Unregistered event is generated with an IAdapterRegistration. """ def registeredAdapters(): """Return an iterable of IAdapterRegistrations. These registrations describe the current adapter registrations in the object. """ def registerSubscriptionAdapter(factory, required=None, provides=None, name=u'', info=''): """Register a subscriber factory Parameters: factory The object used to compute the adapter required This is a sequence of specifications for objects to be adapted. If omitted, then the value of the factory's __component_adapts__ attribute will be used. The __component_adapts__ attribute is usually attribute is normally set in class definitions using adapts function, or for callables using the adapter decorator. If the factory doesn't have a __component_adapts__ adapts attribute, then this argument is required. provided This is the interface provided by the adapter and implemented by the factory. If the factory implements a single interface, then this argument is optional and the factory-implemented interface will be used. name The adapter name. Currently, only the empty string is accepted. Other strings will be accepted in the future when support for named subscribers is added. info An object that can be converted to a string to provide information about the registration. A Registered event is generated with an ISubscriptionAdapterRegistration. """ def unregisterSubscriptionAdapter(factory=None, required=None, provides=None, name=u''): """Register a subscriber factory A boolean is returned indicating whether the registry was changed. If the given component is None and there is no component registered, or if the given component is not None and is not registered, then the function returns False, otherwise it returns True. Parameters: factory This is the object used to compute the adapter. The factory can be None, in which case any factories registered to implement the given provided interface for the given required specifications with the given name are unregistered. required This is a sequence of specifications for objects to be adapted. If the factory is not None and the required arguments is omitted, then the value of the factory's __component_adapts__ attribute will be used. The __component_adapts__ attribute attribute is normally set in class definitions using adapts function, or for callables using the adapter decorator. If the factory is None or doesn't have a __component_adapts__ adapts attribute, then this argument is required. provided This is the interface provided by the adapter and implemented by the factory. If the factory is not None implements a single interface, then this argument is optional and the factory-implemented interface will be used. name The adapter name. Currently, only the empty string is accepted. Other strings will be accepted in the future when support for named subscribers is added. An Unregistered event is generated with an ISubscriptionAdapterRegistration. """ def registeredSubscriptionAdapters(): """Return an iterable of ISubscriptionAdapterRegistrations. These registrations describe the current subscription adapter registrations in the object. """ def registerHandler(handler, adapts=None, name=u'', info=''): """Register a handler. A handler is a subscriber that doesn't compute an adapter but performs some function when called. Parameters: handler The object used to handle some event represented by the objects passed to it. required This is a sequence of specifications for objects to be adapted. If omitted, then the value of the factory's __component_adapts__ attribute will be used. The __component_adapts__ attribute is usually attribute is normally set in class definitions using adapts function, or for callables using the adapter decorator. If the factory doesn't have a __component_adapts__ adapts attribute, then this argument is required. name The handler name. Currently, only the empty string is accepted. Other strings will be accepted in the future when support for named handlers is added. info An object that can be converted to a string to provide information about the registration. A Registered event is generated with an IHandlerRegistration. """ def unregisterHandler(handler=None, adapts=None, name=u''): """Register a handler. A handler is a subscriber that doesn't compute an adapter but performs some function when called. Parameters: handler This is the object used to handle some event represented by the objects passed to it. The handler can be None, in which case any handlers registered for the given required specifications with the given are unregistered. required This is a sequence of specifications for objects to be adapted. If omitted, then the value of the factory's __component_adapts__ attribute will be used. The __component_adapts__ attribute is usually attribute is normally set in class definitions using adapts function, or for callables using the adapter decorator. If the factory doesn't have a __component_adapts__ adapts attribute, then this argument is required. name The handler name. Currently, only the empty string is accepted. Other strings will be accepted in the future when support for named handlers is added. An Unregistered event is generated with an IHandlerRegistration. """ def registeredHandlers(): """Return an iterable of IHandlerRegistrations. These registrations describe the current handler registrations in the object. """ class IComponents(IComponentLookup, IComponentRegistry): """Component registration and access """