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)
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
