############################################################################## # # Copyright (c) 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. # ############################################################################## """Interface Package Interfaces """ from __future__ import absolute_import __docformat__ = 'restructuredtext' from .interface import Attribute from .interface import Interface from .declarations import implementer _BLANK = u'' class IElement(Interface): """Objects that have basic documentation and tagged values. """ __name__ = Attribute('__name__', 'The object name') __doc__ = Attribute('__doc__', 'The object doc string') def getTaggedValue(tag): """Returns the value associated with `tag`. Raise a `KeyError` of the tag isn't set. """ def queryTaggedValue(tag, default=None): """Returns the value associated with `tag`. Return the default value of the tag isn't set. """ def getTaggedValueTags(): """Returns a list of all tags.""" def setTaggedValue(tag, value): """Associates `value` with `key`.""" class IAttribute(IElement): """Attribute descriptors""" interface = Attribute('interface', 'Stores the interface instance in which the ' 'attribute is located.') class IMethod(IAttribute): """Method attributes""" def getSignatureInfo(): """Returns the signature information. This method returns a dictionary with the following keys: o `positional` - All positional arguments. o `required` - A list of all required arguments. o `optional` - A list of all optional arguments. o `varargs` - The name of the varargs argument. o `kwargs` - The name of the kwargs argument. """ def getSignatureString(): """Return a signature string suitable for inclusion in documentation. This method returns the function signature string. For example, if you have `func(a, b, c=1, d='f')`, then the signature string is `(a, b, c=1, d='f')`. """ class ISpecification(Interface): """Object Behavioral specifications""" def providedBy(object): """Test whether the interface is implemented by the object Return true of the object asserts that it implements the interface, including asserting that it implements an extended interface. """ def implementedBy(class_): """Test whether the interface is implemented by instances of the class Return true of the class asserts that its instances implement the interface, including asserting that they implement an extended interface. """ def isOrExtends(other): """Test whether the specification is or extends another """ def extends(other, strict=True): """Test whether a specification extends another The specification extends other if it has other as a base interface or if one of it's bases extends other. If strict is false, then the specification extends itself. """ def weakref(callback=None): """Return a weakref to the specification This method is, regrettably, needed to allow weakrefs to be computed to security-proxied specifications. While the zope.interface package does not require zope.security or zope.proxy, it has to be able to coexist with it. """ __bases__ = Attribute("""Base specifications A tuple if specifications from which this specification is directly derived. """) __sro__ = Attribute("""Specification-resolution order A tuple of the specification and all of it's ancestor specifications from most specific to least specific. (This is similar to the method-resolution order for new-style classes.) """) __iro__ = Attribute("""Interface-resolution order A tuple of the of the specification's ancestor interfaces from most specific to least specific. The specification itself is included if it is an interface. (This is similar to the method-resolution order for new-style classes.) """) def get(name, default=None): """Look up the description for a name If the named attribute is not defined, the default is returned. """ class IInterface(ISpecification, IElement): """Interface objects Interface objects describe the behavior of an object by containing useful information about the object. This information includes: o Prose documentation about the object. In Python terms, this is called the "doc string" of the interface. In this element, you describe how the object works in prose language and any other useful information about the object. o Descriptions of attributes. Attribute descriptions include the name of the attribute and prose documentation describing the attributes usage. o Descriptions of methods. Method descriptions can include: - Prose "doc string" documentation about the method and its usage. - A description of the methods arguments; how many arguments are expected, optional arguments and their default values, the position or arguments in the signature, whether the method accepts arbitrary arguments and whether the method accepts arbitrary keyword arguments. o Optional tagged data. Interface objects (and their attributes and methods) can have optional, application specific tagged data associated with them. Examples uses for this are examples, security assertions, pre/post conditions, and other possible information you may want to associate with an Interface or its attributes. Not all of this information is mandatory. For example, you may only want the methods of your interface to have prose documentation and not describe the arguments of the method in exact detail. Interface objects are flexible and let you give or take any of these components. Interfaces are created with the Python class statement using either Interface.Interface or another interface, as in:: from zope.interface import Interface class IMyInterface(Interface): '''Interface documentation''' def meth(arg1, arg2): '''Documentation for meth''' # Note that there is no self argument class IMySubInterface(IMyInterface): '''Interface documentation''' def meth2(): '''Documentation for meth2''' You use interfaces in two ways: o You assert that your object implement the interfaces. There are several ways that you can assert that an object implements an interface: 1. Call zope.interface.implements in your class definition. 2. Call zope.interfaces.directlyProvides on your object. 3. Call 'zope.interface.classImplements' to assert that instances of a class implement an interface. For example:: from zope.interface import classImplements classImplements(some_class, some_interface) This approach is useful when it is not an option to modify the class source. Note that this doesn't affect what the class itself implements, but only what its instances implement. o You query interface meta-data. See the IInterface methods and attributes for details. """ def names(all=False): """Get the interface attribute names Return a sequence of the names of the attributes, including methods, included in the interface definition. Normally, only directly defined attributes are included. If a true positional or keyword argument is given, then attributes defined by base classes will be included. """ def namesAndDescriptions(all=False): """Get the interface attribute names and descriptions Return a sequence of the names and descriptions of the attributes, including methods, as name-value pairs, included in the interface definition. Normally, only directly defined attributes are included. If a true positional or keyword argument is given, then attributes defined by base classes will be included. """ def __getitem__(name): """Get the description for a name If the named attribute is not defined, a KeyError is raised. """ def direct(name): """Get the description for the name if it was defined by the interface If the interface doesn't define the name, returns None. """ def validateInvariants(obj, errors=None): """Validate invariants Validate object to defined invariants. If errors is None, raises first Invalid error; if errors is a list, appends all errors to list, then raises Invalid with the errors as the first element of the "args" tuple.""" def __contains__(name): """Test whether the name is defined by the interface""" def __iter__(): """Return an iterator over the names defined by the interface The names iterated include all of the names defined by the interface directly and indirectly by base interfaces. """ __module__ = Attribute("""The name of the module defining the interface""") class IDeclaration(ISpecification): """Interface declaration Declarations are used to express the interfaces implemented by classes or provided by objects. """ def __contains__(interface): """Test whether an interface is in the specification Return true if the given interface is one of the interfaces in the specification and false otherwise. """ def __iter__(): """Return an iterator for the interfaces in the specification """ def flattened(): """Return an iterator of all included and extended interfaces An iterator is returned for all interfaces either included in or extended by interfaces included in the specifications without duplicates. The interfaces are in "interface resolution order". The interface resolution order is such that base interfaces are listed after interfaces that extend them and, otherwise, interfaces are included in the order that they were defined in the specification. """ def __sub__(interfaces): """Create an interface specification with some interfaces excluded The argument can be an interface or an interface specifications. The interface or interfaces given in a specification are subtracted from the interface specification. Removing an interface that is not in the specification does not raise an error. Doing so has no effect. Removing an interface also removes sub-interfaces of the interface. """ def __add__(interfaces): """Create an interface specification with some interfaces added The argument can be an interface or an interface specifications. The interface or interfaces given in a specification are added to the interface specification. Adding an interface that is already in the specification does not raise an error. Doing so has no effect. """ def __nonzero__(): """Return a true value of the interface specification is non-empty """ class IInterfaceDeclaration(Interface): """Declare and check the interfaces of objects The functions defined in this interface are used to declare the interfaces that objects provide and to query the interfaces that have been declared. Interfaces can be declared for objects in two ways: - Interfaces are declared for instances of the object's class - Interfaces are declared for the object directly. The interfaces declared for an object are, therefore, the union of interfaces declared for the object directly and the interfaces declared for instances of the object's class. Note that we say that a class implements the interfaces provided by it's instances. An instance can also provide interfaces directly. The interfaces provided by an object are the union of the interfaces provided directly and the interfaces implemented by the class. """ def providedBy(ob): """Return the interfaces provided by an object This is the union of the interfaces directly provided by an object and interfaces implemented by it's class. The value returned is an IDeclaration. """ def implementedBy(class_): """Return the interfaces implemented for a class' instances The value returned is an IDeclaration. """ def classImplements(class_, *interfaces): """Declare additional interfaces implemented for instances of a class The arguments after the class are one or more interfaces or interface specifications (IDeclaration objects). The interfaces given (including the interfaces in the specifications) are added to any interfaces previously declared. Consider the following example:: class C(A, B): ... classImplements(C, I1, I2) Instances of ``C`` provide ``I1``, ``I2``, and whatever interfaces instances of ``A`` and ``B`` provide. """ def implementer(*interfaces): """Create a decorator for declaring interfaces implemented by a facory A callable is returned that makes an implements declaration on objects passed to it. """ def classImplementsOnly(class_, *interfaces): """Declare the only interfaces implemented by instances of a class The arguments after the class are one or more interfaces or interface specifications (IDeclaration objects). The interfaces given (including the interfaces in the specifications) replace any previous declarations. Consider the following example:: class C(A, B): ... classImplements(C, IA, IB. IC) classImplementsOnly(C. I1, I2) Instances of ``C`` provide only ``I1``, ``I2``, and regardless of whatever interfaces instances of ``A`` and ``B`` implement. """ def implementer_only(*interfaces): """Create a decorator for declaring the only interfaces implemented A callable is returned that makes an implements declaration on objects passed to it. """ def directlyProvidedBy(object): """Return the interfaces directly provided by the given object The value returned is an IDeclaration. """ def directlyProvides(object, *interfaces): """Declare interfaces declared directly for an object The arguments after the object are one or more interfaces or interface specifications (IDeclaration objects). The interfaces given (including the interfaces in the specifications) replace interfaces previously declared for the object. Consider the following example:: class C(A, B): ... ob = C() directlyProvides(ob, I1, I2) The object, ``ob`` provides ``I1``, ``I2``, and whatever interfaces instances have been declared for instances of ``C``. To remove directly provided interfaces, use ``directlyProvidedBy`` and subtract the unwanted interfaces. For example:: directlyProvides(ob, directlyProvidedBy(ob)-I2) removes I2 from the interfaces directly provided by ``ob``. The object, ``ob`` no longer directly provides ``I2``, although it might still provide ``I2`` if it's class implements ``I2``. To add directly provided interfaces, use ``directlyProvidedBy`` and include additional interfaces. For example:: directlyProvides(ob, directlyProvidedBy(ob), I2) adds I2 to the interfaces directly provided by ob. """ def alsoProvides(object, *interfaces): """Declare additional interfaces directly for an object:: alsoProvides(ob, I1) is equivalent to:: directlyProvides(ob, directlyProvidedBy(ob), I1) """ def noLongerProvides(object, interface): """Remove an interface from the list of an object's directly provided interfaces:: noLongerProvides(ob, I1) is equivalent to:: directlyProvides(ob, directlyProvidedBy(ob)-I1) with the exception that if ``I1`` is an interface that is provided by ``ob`` through the class's implementation, ValueError is raised. """ def implements(*interfaces): """Declare interfaces implemented by instances of a class This function is called in a class definition (Python 2.x only). The arguments are one or more interfaces or interface specifications (IDeclaration objects). The interfaces given (including the interfaces in the specifications) are added to any interfaces previously declared. Previous declarations include declarations for base classes unless implementsOnly was used. This function is provided for convenience. It provides a more convenient way to call classImplements. For example:: implements(I1) is equivalent to calling:: classImplements(C, I1) after the class has been created. Consider the following example (Python 2.x only):: class C(A, B): implements(I1, I2) Instances of ``C`` implement ``I1``, ``I2``, and whatever interfaces instances of ``A`` and ``B`` implement. """ def implementsOnly(*interfaces): """Declare the only interfaces implemented by instances of a class This function is called in a class definition (Python 2.x only). The arguments are one or more interfaces or interface specifications (IDeclaration objects). Previous declarations including declarations for base classes are overridden. This function is provided for convenience. It provides a more convenient way to call classImplementsOnly. For example:: implementsOnly(I1) is equivalent to calling:: classImplementsOnly(I1) after the class has been created. Consider the following example (Python 2.x only):: class C(A, B): implementsOnly(I1, I2) Instances of ``C`` implement ``I1``, ``I2``, regardless of what instances of ``A`` and ``B`` implement. """ def classProvides(*interfaces): """Declare interfaces provided directly by a class This function is called in a class definition. The arguments are one or more interfaces or interface specifications (IDeclaration objects). The given interfaces (including the interfaces in the specifications) are used to create the class's direct-object interface specification. An error will be raised if the module class has an direct interface specification. In other words, it is an error to call this function more than once in a class definition. Note that the given interfaces have nothing to do with the interfaces implemented by instances of the class. This function is provided for convenience. It provides a more convenient way to call directlyProvides for a class. For example:: classProvides(I1) is equivalent to calling:: directlyProvides(theclass, I1) after the class has been created. """ def provider(*interfaces): """A class decorator version of classProvides""" def moduleProvides(*interfaces): """Declare interfaces provided by a module This function is used in a module definition. The arguments are one or more interfaces or interface specifications (IDeclaration objects). The given interfaces (including the interfaces in the specifications) are used to create the module's direct-object interface specification. An error will be raised if the module already has an interface specification. In other words, it is an error to call this function more than once in a module definition. This function is provided for convenience. It provides a more convenient way to call directlyProvides for a module. For example:: moduleImplements(I1) is equivalent to:: directlyProvides(sys.modules[__name__], I1) """ def Declaration(*interfaces): """Create an interface specification The arguments are one or more interfaces or interface specifications (IDeclaration objects). A new interface specification (IDeclaration) with the given interfaces is returned. """ class IAdapterRegistry(Interface): """Provide an interface-based registry for adapters This registry registers objects that are in some sense "from" a sequence of specification to an interface and a name. No specific semantics are assumed for the registered objects, however, the most common application will be to register factories that adapt objects providing required specifications to a provided interface. """ def register(required, provided, name, value): """Register a value A value is registered for a *sequence* of required specifications, a provided interface, and a name, which must be text. """ def registered(required, provided, name=_BLANK): """Return the component registered for the given interfaces and name name must be text. Unlike the lookup method, this methods won't retrieve components registered for more specific required interfaces or less specific provided interfaces. If no component was registered exactly for the given interfaces and name, then None is returned. """ def lookup(required, provided, name='', default=None): """Lookup a value A value is looked up based on a *sequence* of required specifications, a provided interface, and a name, which must be text. """ def queryMultiAdapter(objects, provided, name=_BLANK, default=None): """Adapt a sequence of objects to a named, provided, interface """ def lookup1(required, provided, name=_BLANK, default=None): """Lookup a value using a single required interface A value is looked up based on a single required specifications, a provided interface, and a name, which must be text. """ def queryAdapter(object, provided, name=_BLANK, default=None): """Adapt an object using a registered adapter factory. """ def adapter_hook(provided, object, name=_BLANK, default=None): """Adapt an object using a registered adapter factory. name must be text. """ def lookupAll(required, provided): """Find all adapters from the required to the provided interfaces An iterable object is returned that provides name-value two-tuples. """ def names(required, provided): """Return the names for which there are registered objects """ def subscribe(required, provided, subscriber, name=_BLANK): """Register a subscriber A subscriber is registered for a *sequence* of required specifications, a provided interface, and a name. Multiple subscribers may be registered for the same (or equivalent) interfaces. """ def subscriptions(required, provided, name=_BLANK): """Get a sequence of subscribers Subscribers for a *sequence* of required interfaces, and a provided interface are returned. """ def subscribers(objects, provided, name=_BLANK): """Get a sequence of subscription adapters """ # begin formerly in zope.component class ComponentLookupError(LookupError): """A component could not be found.""" class Invalid(Exception): """A component doesn't satisfy a promise.""" class IObjectEvent(Interface): """An event related to an object. The object that generated this event is not necessarily the object refered to by location. """ object = Attribute("The subject of the event.") @implementer(IObjectEvent) class ObjectEvent(object): def __init__(self, object): self.object = object class IComponentLookup(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 = Attribute( "Adapter Registry to manage all registered adapters.") utilities = Attribute( "Adapter Registry to manage all registered utilities.") def queryAdapter(object, interface, name=_BLANK, 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=_BLANK): """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=_BLANK, default=None): """Look for a multi-adapter to an interface for multiple objects If a matching adapter cannot be found, returns the default. """ def getMultiAdapter(objects, interface, name=_BLANK): """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. """ class IRegistration(Interface): """A registration-information object """ registry = Attribute("The registry having the registration") name = Attribute("The registration name") info = 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 """ factory = Attribute("The factory used to create the utility. Optional.") component = Attribute("The object registered") provided = Attribute("The interface provided by the component") class _IBaseAdapterRegistration(IRegistration): """Information about the registration of an adapter """ factory = Attribute("The factory used to create adapters") required = 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 = 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 = Attribute("An object called used to handle an event") required = 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""" @implementer(IRegistrationEvent) class RegistrationEvent(ObjectEvent): """There has been a change in a registration """ def __repr__(self): return "%s event:\n%r" % (self.__class__.__name__, self.object) class IRegistered(IRegistrationEvent): """A component or factory was registered """ @implementer(IRegistered) class Registered(RegistrationEvent): pass class IUnregistered(IRegistrationEvent): """A component or factory was unregistered """ @implementer(IUnregistered) class Unregistered(RegistrationEvent): """A component or factory was unregistered """ pass class IComponentRegistry(Interface): """Register components """ def registerUtility(component=None, provided=None, name=_BLANK, info=_BLANK, factory=None): """Register a utility factory Factory for the component to be registerd. 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. Only one of component and factory can be used. A Registered event is generated with an IUtilityRegistration. """ def unregisterUtility(component=None, provided=None, name=_BLANK, factory=None): """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. factory Factory for the component to be unregisterd. 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. Only one of component and factory can be used. An UnRegistered event is generated with an IUtilityRegistration. """ def registeredUtilities(): """Return an iterable of IUtilityRegistration instances. These registrations describe the current utility registrations in the object. """ def registerAdapter(factory, required=None, provided=None, name=_BLANK, info=_BLANK): """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=_BLANK): """Unregister 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 IAdapterRegistration instances. These registrations describe the current adapter registrations in the object. """ def registerSubscriptionAdapter(factory, required=None, provides=None, name=_BLANK, 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=_BLANK): """Unregister 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 ISubscriptionAdapterRegistration instances. These registrations describe the current subscription adapter registrations in the object. """ def registerHandler(handler, required=None, name=_BLANK, 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, required=None, name=_BLANK): """Unregister a handler. A handler is a subscriber that doesn't compute an adapter but performs some function when called. A boolean is returned indicating whether the registry was changed. 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 IHandlerRegistration instances. These registrations describe the current handler registrations in the object. """ class IComponents(IComponentLookup, IComponentRegistry): """Component registration and access """ # end formerly in zope.component