def _encode(inner_obj):
encoded = inner_obj
# encode resource objects with their specified serializer,
# according to the highest level of access which the environment arguments allow
if getattr(inner_obj, '_IS_RESOURCE', False):
# determine the access level in this environment
permission = self._access_level(obj, environment)
# retrieve the serializer
serializer = getattr(inner_obj, self.serialization_method_name, None)
if serializer is not None:
# encode the resource using its serializer with the provided permission
serializer_kwargs = populate_args(serializer, {'permission': permission}, environment)
encoded = serializer(**serializer_kwargs)
else:
raise ValueError("Unable to serialize: object '" + obj.__name__ + "' has no method '" + self.serialization_method_name + "'")
elif isinstance(inner_obj, collections.Mapping):
# recurse on dictionary-like objects
encoded = {}
for key, val in inner_obj.iteritems():
encoded[key] = _encode(val)
elif isinstance(inner_obj, collections.Iterable):
# recurse on array-like objects
encoded = []
for val in inner_obj:
encoded.append(_encode(val))
return encoded
def _commit(self, name, instance, environment, encode=True):
commit_result = None
# commit changes to the resource
if self.is_transactional.get(name, True):
commit_method = getattr(instance, self.commit_method_name, None)
if commit_method is not None:
commit_kwargs = populate_args(commit_method, environment)
commit_result = commit_result(**commit_kwargs)
if encode:
commit_result = self.encode(commit_result, environment)
return commit_result
def _access_level(self, resource_instance, environment):
"""Determine a resource's most restrictive access permission for a given environment"""
# determine if the resource instance has a method to provide the
# highest level of access this environment can give
access_level_method = getattr(resource_instance, self.access_level_method_name, None)
if access_level_method is not None:
access_level_kwargs = populate_args(access_level_method, environment)
access_level = access_level_method(**access_level_kwargs)
else:
# fall back on calling its access method in the provided
# permissions order
access_method = getattr(resource_instance, self.access_method_name, None)
access_level = None
if access_method is not None:
for permission in self.permission_order:
access_kwargs = populate_args(access_method, {'permission': permission}, environment)
if access_method(**access_kwargs):
access_method = permission
break
return access_level
def _call(self, class_obj, parent, methods, access_method_name, environment, allowed_method_types=None, encode=True):
"""Performs access and permission checking, calls each specified method
(its arguments are combined with the provided environment).
"""
# look up the access method to check for access
access_method = getattr(parent, access_method_name, None)
if access_method is None:
raise ResourceMethodNotFoundError("'" + class_obj.__name__ + "' is missing an access method")
# check if this is an acceptable method of execution as per allowed_method_types
if allowed_method_types is not None and method._method_type not in allowed_method_types:
raise ResourceNotAllowedError("'" + class_obj.__name__ + "' is not allowed to access '" + method_name + "' in this manner")
# check that access can be granted to call this method
permission = method._permission
access_kwargs = populate_args(access_method, {'permission': permission}, environment)
if not access_method(**access_kwargs):
raise ResourceAccessDeniedError("'" + class_obj.__name__ + "' has denied access to '" + method_name + "'")
result = []
for method_data in methods:
if isinstance(method_data, basestring):
method_name = method_data
sent_arguments = {}
else:
method_name = method_data.get('method')
sent_arguments = method_data.get('args')
method_name = method_name.lower()
if method_name in self.method_names:
err = ResourceMethodNotFoundError("'" + class_obj.__name__ + "' cannot export method '" + method_name + "'")
err.method = method_name
err.args = sent_arguments
raise err
class_method = getattr(class_obj, method_name, None)
if isinstance(class_method, property):
# this "method" is a decorated property
num_args = len(sent_arguments)
try:
if num_args == 0:
result.append(getattr(parent, method_name))
elif method_name in sent_arguments:
value = sent_arguments[method_name]
setattr(parent, method_name, value)
result.append(value)
except Exception as original_err:
# pass on the error information
trace = sys.exc_info()[2]
err = ResourceMethodFailedError("'" + class_obj.__name__ + "' failed to execute '" + method_name + "'")
err.method = method_name
err.args = sent_arguments
err.error = original_err
err.trace = trace
raise err, None, trace
elif callable(class_method):
# this is a callable method
# lookup the method and ensure it is exported
method = getattr(parent, method_name, None)
if method is None or not getattr(method, '_is_exported', False):
err = ResourceMethodNotFoundError("'" + class_obj.__name__ + "' has no exported method '" + method_name + "'")
err.method = method_name
err.args = sent_arguments
raise err
method_kwargs = populate_args(method, sent_arguments, environment)
try:
call_result = method(**method_kwargs)
except Exception as original_err:
# pass on the error information
trace = sys.exc_info()[2]
err = ResourceMethodFailedError("'" + class_obj.__name__ + "' failed to execute '" + method_name + "'")
err.method = method_name
err.args = sent_arguments
err.error = original_err
err.trace = trace
raise err, None, trace
result.append(call_result)
else:
err = ResourceMethodNotFoundError("'" + class_obj.__name__ + "' has no method or decorated property '" + method_name + "'")
err.method = method_name
err.args = sent_arguments
raise err
if encode:
result = self.encode(result, environment)
return result
