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- import errno
- import os
- import types
- import typing as t
- from werkzeug.utils import import_string
- class ConfigAttribute:
- """Makes an attribute forward to the config"""
- def __init__(self, name: str, get_converter: t.Optional[t.Callable] = None) -> None:
- self.__name__ = name
- self.get_converter = get_converter
- def __get__(self, obj: t.Any, owner: t.Any = None) -> t.Any:
- if obj is None:
- return self
- rv = obj.config[self.__name__]
- if self.get_converter is not None:
- rv = self.get_converter(rv)
- return rv
- def __set__(self, obj: t.Any, value: t.Any) -> None:
- obj.config[self.__name__] = value
- class Config(dict):
- """Works exactly like a dict but provides ways to fill it from files
- or special dictionaries. There are two common patterns to populate the
- config.
- Either you can fill the config from a config file::
- app.config.from_pyfile('yourconfig.cfg')
- Or alternatively you can define the configuration options in the
- module that calls :meth:`from_object` or provide an import path to
- a module that should be loaded. It is also possible to tell it to
- use the same module and with that provide the configuration values
- just before the call::
- DEBUG = True
- SECRET_KEY = 'development key'
- app.config.from_object(__name__)
- In both cases (loading from any Python file or loading from modules),
- only uppercase keys are added to the config. This makes it possible to use
- lowercase values in the config file for temporary values that are not added
- to the config or to define the config keys in the same file that implements
- the application.
- Probably the most interesting way to load configurations is from an
- environment variable pointing to a file::
- app.config.from_envvar('YOURAPPLICATION_SETTINGS')
- In this case before launching the application you have to set this
- environment variable to the file you want to use. On Linux and OS X
- use the export statement::
- export YOURAPPLICATION_SETTINGS='/path/to/config/file'
- On windows use `set` instead.
- :param root_path: path to which files are read relative from. When the
- config object is created by the application, this is
- the application's :attr:`~flask.Flask.root_path`.
- :param defaults: an optional dictionary of default values
- """
- def __init__(self, root_path: str, defaults: t.Optional[dict] = None) -> None:
- dict.__init__(self, defaults or {})
- self.root_path = root_path
- def from_envvar(self, variable_name: str, silent: bool = False) -> bool:
- """Loads a configuration from an environment variable pointing to
- a configuration file. This is basically just a shortcut with nicer
- error messages for this line of code::
- app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS'])
- :param variable_name: name of the environment variable
- :param silent: set to ``True`` if you want silent failure for missing
- files.
- :return: ``True`` if the file was loaded successfully.
- """
- rv = os.environ.get(variable_name)
- if not rv:
- if silent:
- return False
- raise RuntimeError(
- f"The environment variable {variable_name!r} is not set"
- " and as such configuration could not be loaded. Set"
- " this variable and make it point to a configuration"
- " file"
- )
- return self.from_pyfile(rv, silent=silent)
- def from_pyfile(self, filename: str, silent: bool = False) -> bool:
- """Updates the values in the config from a Python file. This function
- behaves as if the file was imported as module with the
- :meth:`from_object` function.
- :param filename: the filename of the config. This can either be an
- absolute filename or a filename relative to the
- root path.
- :param silent: set to ``True`` if you want silent failure for missing
- files.
- :return: ``True`` if the file was loaded successfully.
- .. versionadded:: 0.7
- `silent` parameter.
- """
- filename = os.path.join(self.root_path, filename)
- d = types.ModuleType("config")
- d.__file__ = filename
- try:
- with open(filename, mode="rb") as config_file:
- exec(compile(config_file.read(), filename, "exec"), d.__dict__)
- except OSError as e:
- if silent and e.errno in (errno.ENOENT, errno.EISDIR, errno.ENOTDIR):
- return False
- e.strerror = f"Unable to load configuration file ({e.strerror})"
- raise
- self.from_object(d)
- return True
- def from_object(self, obj: t.Union[object, str]) -> None:
- """Updates the values from the given object. An object can be of one
- of the following two types:
- - a string: in this case the object with that name will be imported
- - an actual object reference: that object is used directly
- Objects are usually either modules or classes. :meth:`from_object`
- loads only the uppercase attributes of the module/class. A ``dict``
- object will not work with :meth:`from_object` because the keys of a
- ``dict`` are not attributes of the ``dict`` class.
- Example of module-based configuration::
- app.config.from_object('yourapplication.default_config')
- from yourapplication import default_config
- app.config.from_object(default_config)
- Nothing is done to the object before loading. If the object is a
- class and has ``@property`` attributes, it needs to be
- instantiated before being passed to this method.
- You should not use this function to load the actual configuration but
- rather configuration defaults. The actual config should be loaded
- with :meth:`from_pyfile` and ideally from a location not within the
- package because the package might be installed system wide.
- See :ref:`config-dev-prod` for an example of class-based configuration
- using :meth:`from_object`.
- :param obj: an import name or object
- """
- if isinstance(obj, str):
- obj = import_string(obj)
- for key in dir(obj):
- if key.isupper():
- self[key] = getattr(obj, key)
- def from_file(
- self,
- filename: str,
- load: t.Callable[[t.IO[t.Any]], t.Mapping],
- silent: bool = False,
- ) -> bool:
- """Update the values in the config from a file that is loaded
- using the ``load`` parameter. The loaded data is passed to the
- :meth:`from_mapping` method.
- .. code-block:: python
- import toml
- app.config.from_file("config.toml", load=toml.load)
- :param filename: The path to the data file. This can be an
- absolute path or relative to the config root path.
- :param load: A callable that takes a file handle and returns a
- mapping of loaded data from the file.
- :type load: ``Callable[[Reader], Mapping]`` where ``Reader``
- implements a ``read`` method.
- :param silent: Ignore the file if it doesn't exist.
- :return: ``True`` if the file was loaded successfully.
- .. versionadded:: 2.0
- """
- filename = os.path.join(self.root_path, filename)
- try:
- with open(filename) as f:
- obj = load(f)
- except OSError as e:
- if silent and e.errno in (errno.ENOENT, errno.EISDIR):
- return False
- e.strerror = f"Unable to load configuration file ({e.strerror})"
- raise
- return self.from_mapping(obj)
- def from_json(self, filename: str, silent: bool = False) -> bool:
- """Update the values in the config from a JSON file. The loaded
- data is passed to the :meth:`from_mapping` method.
- :param filename: The path to the JSON file. This can be an
- absolute path or relative to the config root path.
- :param silent: Ignore the file if it doesn't exist.
- :return: ``True`` if the file was loaded successfully.
- .. deprecated:: 2.0.0
- Will be removed in Flask 2.1. Use :meth:`from_file` instead.
- This was removed early in 2.0.0, was added back in 2.0.1.
- .. versionadded:: 0.11
- """
- import warnings
- from . import json
- warnings.warn(
- "'from_json' is deprecated and will be removed in Flask"
- " 2.1. Use 'from_file(path, json.load)' instead.",
- DeprecationWarning,
- stacklevel=2,
- )
- return self.from_file(filename, json.load, silent=silent)
- def from_mapping(
- self, mapping: t.Optional[t.Mapping[str, t.Any]] = None, **kwargs: t.Any
- ) -> bool:
- """Updates the config like :meth:`update` ignoring items with non-upper
- keys.
- :return: Always returns ``True``.
- .. versionadded:: 0.11
- """
- mappings: t.Dict[str, t.Any] = {}
- if mapping is not None:
- mappings.update(mapping)
- mappings.update(kwargs)
- for key, value in mappings.items():
- if key.isupper():
- self[key] = value
- return True
- def get_namespace(
- self, namespace: str, lowercase: bool = True, trim_namespace: bool = True
- ) -> t.Dict[str, t.Any]:
- """Returns a dictionary containing a subset of configuration options
- that match the specified namespace/prefix. Example usage::
- app.config['IMAGE_STORE_TYPE'] = 'fs'
- app.config['IMAGE_STORE_PATH'] = '/var/app/images'
- app.config['IMAGE_STORE_BASE_URL'] = 'http://img.website.com'
- image_store_config = app.config.get_namespace('IMAGE_STORE_')
- The resulting dictionary `image_store_config` would look like::
- {
- 'type': 'fs',
- 'path': '/var/app/images',
- 'base_url': 'http://img.website.com'
- }
- This is often useful when configuration options map directly to
- keyword arguments in functions or class constructors.
- :param namespace: a configuration namespace
- :param lowercase: a flag indicating if the keys of the resulting
- dictionary should be lowercase
- :param trim_namespace: a flag indicating if the keys of the resulting
- dictionary should not include the namespace
- .. versionadded:: 0.11
- """
- rv = {}
- for k, v in self.items():
- if not k.startswith(namespace):
- continue
- if trim_namespace:
- key = k[len(namespace) :]
- else:
- key = k
- if lowercase:
- key = key.lower()
- rv[key] = v
- return rv
- def __repr__(self) -> str:
- return f"<{type(self).__name__} {dict.__repr__(self)}>"
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