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Diffstat (limited to 'venv/lib/python3.8/site-packages/flask/config.py')
| -rw-r--r-- | venv/lib/python3.8/site-packages/flask/config.py | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/venv/lib/python3.8/site-packages/flask/config.py b/venv/lib/python3.8/site-packages/flask/config.py new file mode 100644 index 0000000..7e3ba17 --- /dev/null +++ b/venv/lib/python3.8/site-packages/flask/config.py @@ -0,0 +1,370 @@ +from __future__ import annotations + +import errno +import json +import os +import types +import typing as t + +from werkzeug.utils import import_string + +if t.TYPE_CHECKING: + import typing_extensions as te + + from .sansio.app import App + + +T = t.TypeVar("T") + + +class ConfigAttribute(t.Generic[T]): + """Makes an attribute forward to the config""" + + def __init__( + self, name: str, get_converter: t.Callable[[t.Any], T] | None = None + ) -> None: + self.__name__ = name + self.get_converter = get_converter + + @t.overload + def __get__(self, obj: None, owner: None) -> te.Self: ... + + @t.overload + def __get__(self, obj: App, owner: type[App]) -> T: ... + + def __get__(self, obj: App | None, owner: type[App] | None = None) -> T | te.Self: + 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 # type: ignore[no-any-return] + + def __set__(self, obj: App, value: t.Any) -> None: + obj.config[self.__name__] = value + + +class Config(dict): # type: ignore[type-arg] + """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 | os.PathLike[str], + defaults: dict[str, t.Any] | None = None, + ) -> None: + super().__init__(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_prefixed_env( + self, prefix: str = "FLASK", *, loads: t.Callable[[str], t.Any] = json.loads + ) -> bool: + """Load any environment variables that start with ``FLASK_``, + dropping the prefix from the env key for the config key. Values + are passed through a loading function to attempt to convert them + to more specific types than strings. + + Keys are loaded in :func:`sorted` order. + + The default loading function attempts to parse values as any + valid JSON type, including dicts and lists. + + Specific items in nested dicts can be set by separating the + keys with double underscores (``__``). If an intermediate key + doesn't exist, it will be initialized to an empty dict. + + :param prefix: Load env vars that start with this prefix, + separated with an underscore (``_``). + :param loads: Pass each string value to this function and use + the returned value as the config value. If any error is + raised it is ignored and the value remains a string. The + default is :func:`json.loads`. + + .. versionadded:: 2.1 + """ + prefix = f"{prefix}_" + len_prefix = len(prefix) + + for key in sorted(os.environ): + if not key.startswith(prefix): + continue + + value = os.environ[key] + + try: + value = loads(value) + except Exception: + # Keep the value as a string if loading failed. + pass + + # Change to key.removeprefix(prefix) on Python >= 3.9. + key = key[len_prefix:] + + if "__" not in key: + # A non-nested key, set directly. + self[key] = value + continue + + # Traverse nested dictionaries with keys separated by "__". + current = self + *parts, tail = key.split("__") + + for part in parts: + # If an intermediate dict does not exist, create it. + if part not in current: + current[part] = {} + + current = current[part] + + current[tail] = value + + return True + + def from_pyfile( + self, filename: str | os.PathLike[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: 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 | os.PathLike[str], + load: t.Callable[[t.IO[t.Any]], t.Mapping[str, t.Any]], + silent: bool = False, + text: bool = True, + ) -> 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 json + app.config.from_file("config.json", load=json.load) + + import tomllib + app.config.from_file("config.toml", load=tomllib.load, text=False) + + :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. + :param text: Open the file in text or binary mode. + :return: ``True`` if the file was loaded successfully. + + .. versionchanged:: 2.3 + The ``text`` parameter was added. + + .. versionadded:: 2.0 + """ + filename = os.path.join(self.root_path, filename) + + try: + with open(filename, "r" if text else "rb") 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_mapping( + self, mapping: t.Mapping[str, t.Any] | None = 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: 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 + ) -> 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)}>" |