Class FlaskGroup

src/flask/cli.py:531–696

Special subclass of the :class:`AppGroup` group that supports loading more commands from the configured Flask app. Normally a developer does not have to interface with this class but there are some very advanced use cases for which it makes sense to create an instance of this. see :

class FlaskGroup(AppGroup):
    """Special subclass of the :class:`AppGroup` group that supports
    loading more commands from the configured Flask app.  Normally a
    developer does not have to interface with this class but there are
    some very advanced use cases for which it makes sense to create an
    instance of this. see :ref:`custom-scripts`.

    :param add_default_commands: if this is True then the default run and
        shell commands will be added.
    :param add_version_option: adds the ``--version`` option.
    :param create_app: an optional callback that is passed the script info and
        returns the loaded app.
    :param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv`
        files to set environment variables. Will also change the working
        directory to the directory containing the first file found.
    :param set_debug_flag: Set the app's debug flag.

    .. versionchanged:: 3.1
        ``-e path`` takes precedence over default ``.env`` and ``.flaskenv`` files.

    .. versionchanged:: 2.2
        Added the ``-A/--app``, ``--debug/--no-debug``, ``-e/--env-file`` options.

    .. versionchanged:: 2.2
        An app context is pushed when running ``app.cli`` commands, so
        ``@with_appcontext`` is no longer required for those commands.

    .. versionchanged:: 1.0
        If installed, python-dotenv will be used to load environment variables
        from :file:`.env` and :file:`.flaskenv` files.
    """

    def __init__(
        self,
        add_default_commands: bool = True,
        create_app: t.Callable[..., Flask] | None = None,
        add_version_option: bool = True,
        load_dotenv: bool = True,
        set_debug_flag: bool = True,
        **extra: t.Any,
    ) -> None:
        params: list[click.Parameter] = list(extra.pop("params", None) or ())
        # Processing is done with option callbacks instead of a group
        # callback. This allows users to make a custom group callback
        # without losing the behavior. --env-file must come first so
        # that it is eagerly evaluated before --app.
        params.extend((_env_file_option, _app_option, _debug_option))

        if add_version_option:
            params.append(version_option)

        if "context_settings" not in extra:
            extra["context_settings"] = {}

        extra["context_settings"].setdefault("auto_envvar_prefix", "FLASK")

        super().__init__(params=params, **extra)