Esempio n. 1
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def classImplements(cls, *interfaces):
    """Declare additional interfaces implemented for instances of a class

      The arguments after the class are one or more interfaces or
      interface specifications (`~zope.interface.interfaces.IDeclaration` objects).

      The interfaces given (including the interfaces in the specifications)
      are added to any interfaces previously declared.
    """
    spec = implementedBy(cls)
    spec.declared += tuple(_normalizeargs(interfaces))

    # compute the bases
    bases = []
    seen = {}
    for b in spec.declared:
        if b not in seen:
            seen[b] = 1
            bases.append(b)

    if spec.inherit is not None:

        for c in spec.inherit.__bases__:
            b = implementedBy(c)
            if b not in seen:
                seen[b] = 1
                bases.append(b)

    spec.__bases__ = tuple(bases)
def classImplements(cls, *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.
    """
    spec = implementedBy(cls)
    spec.declared += tuple(_normalizeargs(interfaces))

    # compute the bases
    bases = []
    seen = {}
    for b in spec.declared:
        if b not in seen:
            seen[b] = 1
            bases.append(b)

    if spec.inherit is not None:

        for c in spec.inherit.__bases__:
            b = implementedBy(c)
            if b not in seen:
                seen[b] = 1
                bases.append(b)

    spec.__bases__ = tuple(bases)
Esempio n. 3
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 def __init__(self, cls, metacls, *interfaces):
     self._cls = cls
     self._implements = implementedBy(cls)
     self.__args = (
         cls,
         metacls,
     ) + interfaces
     Declaration.__init__(self, *(interfaces + (implementedBy(metacls), )))
Esempio n. 4
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def providedByFallback(ob):

    # Here we have either a special object, an old-style declaration
    # or a descriptor

    # Try to get __providedBy__
    try:
        r = ob.__providedBy__
    except AttributeError:
        # Not set yet. Fall back to lower-level thing that computes it
        return getObjectSpecification(ob)

    try:
        # We might have gotten a descriptor from an instance of a
        # class (like an ExtensionClass) that doesn't support
        # descriptors.  We'll make sure we got one by trying to get
        # the only attribute, which all specs have.
        r.extends

    except AttributeError:

        # The object's class doesn't understand descriptors.
        # Sigh. We need to get an object descriptor, but we have to be
        # careful.  We want to use the instance's __provides__, if
        # there is one, but only if it didn't come from the class.

        try:
            r = ob.__provides__
        except AttributeError:
            # No __provides__, so just fall back to implementedBy
            return implementedBy(ob.__class__)

        # We need to make sure we got the __provides__ from the
        # instance. We'll do this by making sure we don't get the same
        # thing from the class:

        try:
            cp = ob.__class__.__provides__
        except AttributeError:
            # The ob doesn't have a class or the class has no
            # provides, assume we're done:
            return r

        if r is cp:
            # Oops, we got the provides from the class. This means
            # the object doesn't have it's own. We should use implementedBy
            return implementedBy(ob.__class__)

    return r
def providedByFallback(ob):

    # Here we have either a special object, an old-style declaration
    # or a descriptor

    # Try to get __providedBy__
    try:
        r = ob.__providedBy__
    except AttributeError:
        # Not set yet. Fall back to lower-level thing that computes it
        return getObjectSpecification(ob)

    try:
        # We might have gotten a descriptor from an instance of a
        # class (like an ExtensionClass) that doesn't support
        # descriptors.  We'll make sure we got one by trying to get
        # the only attribute, which all specs have.
        r.extends

    except AttributeError:

        # The object's class doesn't understand descriptors.
        # Sigh. We need to get an object descriptor, but we have to be
        # careful.  We want to use the instance's __provides__, if
        # there is one, but only if it didn't come from the class.

        try:
            r = ob.__provides__
        except AttributeError:
            # No __provides__, so just fall back to implementedBy
            return implementedBy(ob.__class__)

        # We need to make sure we got the __provides__ from the
        # instance. We'll do this by making sure we don't get the same
        # thing from the class:

        try:
            cp = ob.__class__.__provides__
        except AttributeError:
            # The ob doesn't have a class or the class has no
            # provides, assume we're done:
            return r

        if r is cp:
            # Oops, we got the provides from the class. This means
            # the object doesn't have it's own. We should use implementedBy
            return implementedBy(ob.__class__)

    return r
Esempio n. 6
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    def __get__(self, inst, cls):
        """Get an object specification for an object
        """
        if inst is None:
            return getObjectSpecification(cls)

        provides = getattr(inst, '__provides__', None)
        if provides is not None:
            return provides

        return implementedBy(cls)
    def __get__(self, inst, cls):
        """Get an object specification for an object
        """
        if inst is None:
            return getObjectSpecification(cls)

        provides = getattr(inst, '__provides__', None)
        if provides is not None:
            return provides

        return implementedBy(cls)
Esempio n. 8
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def classImplementsOnly(cls, *interfaces):
    """Declare the only interfaces implemented by instances of a class

      The arguments after the class are one or more interfaces or interface
      specifications (`~zope.interface.interfaces.IDeclaration` objects).

      The interfaces given (including the interfaces in the specifications)
      replace any previous declarations.
    """
    spec = implementedBy(cls)
    spec.declared = ()
    spec.inherit = None
    classImplements(cls, *interfaces)
def classImplementsOnly(cls, *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.
    """
    spec = implementedBy(cls)
    spec.declared = ()
    spec.inherit = None
    classImplements(cls, *interfaces)
Esempio n. 10
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def getObjectSpecificationFallback(ob):

    provides = getattr(ob, '__provides__', None)
    if provides is not None:
        if isinstance(provides, SpecificationBase):
            return provides

    try:
        cls = ob.__class__
    except AttributeError:
        # We can't get the class, so just consider provides
        return _empty

    return implementedBy(cls)
def getObjectSpecificationFallback(ob):

    provides = getattr(ob, '__provides__', None)
    if provides is not None:
        if isinstance(provides, SpecificationBase):
            return provides

    try:
        cls = ob.__class__
    except AttributeError:
        # We can't get the class, so just consider provides
        return _empty

    return implementedBy(cls)
Esempio n. 12
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def implementedByFallback(cls):
    """Return the interfaces implemented for a class' instances

      The value returned is an `~zope.interface.interfaces.IDeclaration`.
    """
    try:
        spec = cls.__dict__.get('__implemented__')
    except AttributeError:

        # we can't get the class dict. This is probably due to a
        # security proxy.  If this is the case, then probably no
        # descriptor was installed for the class.

        # We don't want to depend directly on zope.security in
        # zope.interface, but we'll try to make reasonable
        # accommodations in an indirect way.

        # We'll check to see if there's an implements:

        spec = getattr(cls, '__implemented__', None)
        if spec is None:
            # There's no spec stred in the class. Maybe its a builtin:
            spec = BuiltinImplementationSpecifications.get(cls)
            if spec is not None:
                return spec
            return _empty

        if spec.__class__ == Implements:
            # we defaulted to _empty or there was a spec. Good enough.
            # Return it.
            return spec

        # TODO: need old style __implements__ compatibility?
        # Hm, there's an __implemented__, but it's not a spec. Must be
        # an old-style declaration. Just compute a spec for it
        return Declaration(*_normalizeargs((spec, )))

    if isinstance(spec, Implements):
        return spec

    if spec is None:
        spec = BuiltinImplementationSpecifications.get(cls)
        if spec is not None:
            return spec

    # TODO: need old style __implements__ compatibility?
    spec_name = _implements_name(cls)
    if spec is not None:
        # old-style __implemented__ = foo declaration
        spec = (spec, )  # tuplefy, as it might be just an int
        spec = Implements.named(spec_name, *_normalizeargs(spec))
        spec.inherit = None  # old-style implies no inherit
        del cls.__implemented__  # get rid of the old-style declaration
    else:
        try:
            bases = cls.__bases__
        except AttributeError:
            if not callable(cls):
                raise TypeError("ImplementedBy called for non-factory", cls)
            bases = ()

        spec = Implements.named(spec_name, *[implementedBy(c) for c in bases])
        spec.inherit = cls

    try:
        cls.__implemented__ = spec
        if not hasattr(cls, '__providedBy__'):
            cls.__providedBy__ = objectSpecificationDescriptor

        if (isinstance(cls, DescriptorAwareMetaClasses)
                and '__provides__' not in cls.__dict__):
            # Make sure we get a __provides__ descriptor
            cls.__provides__ = ClassProvides(
                cls,
                getattr(cls, '__class__', type(cls)),
            )

    except TypeError:
        if not isinstance(cls, type):
            raise TypeError("ImplementedBy called for non-type", cls)
        BuiltinImplementationSpecifications[cls] = spec

    return spec
 def __init__(self, cls, metacls, *interfaces):
     self._cls = cls
     self._implements = implementedBy(cls)
     self.__args = (cls, metacls, ) + interfaces
     Declaration.__init__(self, *(interfaces + (implementedBy(metacls), )))
def implementedByFallback(cls):
    """Return the interfaces implemented for a class' instances

      The value returned is an IDeclaration.
    """
    try:
        spec = cls.__dict__.get('__implemented__')
    except AttributeError:

        # we can't get the class dict. This is probably due to a
        # security proxy.  If this is the case, then probably no
        # descriptor was installed for the class.

        # We don't want to depend directly on zope.security in
        # zope.interface, but we'll try to make reasonable
        # accommodations in an indirect way.

        # We'll check to see if there's an implements:

        spec = getattr(cls, '__implemented__', None)
        if spec is None:
            # There's no spec stred in the class. Maybe its a builtin:
            spec = BuiltinImplementationSpecifications.get(cls)
            if spec is not None:
                return spec
            return _empty

        if spec.__class__ == Implements:
            # we defaulted to _empty or there was a spec. Good enough.
            # Return it.
            return spec

        # TODO: need old style __implements__ compatibility?
        # Hm, there's an __implemented__, but it's not a spec. Must be
        # an old-style declaration. Just compute a spec for it
        return Declaration(*_normalizeargs((spec, )))

    if isinstance(spec, Implements):
        return spec

    if spec is None:
        spec = BuiltinImplementationSpecifications.get(cls)
        if spec is not None:
            return spec

    # TODO: need old style __implements__ compatibility?
    spec_name = _implements_name(cls)
    if spec is not None:
        # old-style __implemented__ = foo declaration
        spec = (spec, ) # tuplefy, as it might be just an int
        spec = Implements.named(spec_name, *_normalizeargs(spec))
        spec.inherit = None    # old-style implies no inherit
        del cls.__implemented__ # get rid of the old-style declaration
    else:
        try:
            bases = cls.__bases__
        except AttributeError:
            if not callable(cls):
                raise TypeError("ImplementedBy called for non-factory", cls)
            bases = ()

        spec = Implements.named(spec_name, *[implementedBy(c) for c in bases])
        spec.inherit = cls

    try:
        cls.__implemented__ = spec
        if not hasattr(cls, '__providedBy__'):
            cls.__providedBy__ = objectSpecificationDescriptor

        if (isinstance(cls, DescriptorAwareMetaClasses)
            and
            '__provides__' not in cls.__dict__):
            # Make sure we get a __provides__ descriptor
            cls.__provides__ = ClassProvides(
                cls,
                getattr(cls, '__class__', type(cls)),
                )

    except TypeError:
        if not isinstance(cls, type):
            raise TypeError("ImplementedBy called for non-type", cls)
        BuiltinImplementationSpecifications[cls] = spec

    return spec