# Copyright 2015 Huawei Technologies Co., Ltd. # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. import functools import inspect import horizon.exceptions def handle_errors(error_message, error_default=None, request_arg=None): """A decorator for adding default error handling to API calls. It wraps the original method in a try-except block, with horizon's error handling added. Note: it should only be used on functions or methods that take request as their argument (it has to be named "request", or ``request_arg`` has to be provided, indicating which argument is the request). The decorated method accepts a number of additional parameters: :param _error_handle: whether to handle the errors in this call :param _error_message: override the error message :param _error_default: override the default value returned on error :param _error_redirect: specify a redirect url for errors :param _error_ignore: ignore known errors """ def decorator(func): if request_arg is None: _request_arg = 'request' if _request_arg not in inspect.getfullargspec(func).args: raise RuntimeError( "The handle_errors decorator requires 'request' as " "an argument of the function or method being decorated") else: _request_arg = request_arg @functools.wraps(func) def wrapper(*args, **kwargs): _error_handle = kwargs.pop('_error_handle', True) _error_message = kwargs.pop('_error_message', error_message) _error_default = kwargs.pop('_error_default', error_default) _error_redirect = kwargs.pop('_error_redirect', None) _error_ignore = kwargs.pop('_error_ignore', False) if not _error_handle: return func(*args, **kwargs) try: return func(*args, **kwargs) except Exception as e: callargs = inspect.getcallargs(func, *args, **kwargs) request = callargs[_request_arg] _error_message += ': ' + str(e) horizon.exceptions.handle(request, _error_message, ignore=_error_ignore, redirect=_error_redirect) return _error_default wrapper.wrapped = func return wrapper return decorator