forked-synapse/synapse/rest/models.py

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2022 The Matrix.org Foundation C.I.C.
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
from typing import TYPE_CHECKING

from synapse._pydantic_compat import HAS_PYDANTIC_V2

if TYPE_CHECKING or HAS_PYDANTIC_V2:
    from pydantic.v1 import BaseModel, Extra
else:
    from pydantic import BaseModel, Extra


class RequestBodyModel(BaseModel):
    """A custom version of Pydantic's BaseModel which

     - ignores unknown fields and
     - does not allow fields to be overwritten after construction,

    but otherwise uses Pydantic's default behaviour.

    Ignoring unknown fields is a useful default. It means that clients can provide
    unstable field not known to the server without the request being refused outright.

    Subclassing in this way is recommended by
    https://pydantic-docs.helpmanual.io/usage/model_config/#change-behaviour-globally
    """

    class Config:
        # By default, ignore fields that we don't recognise.
        extra = Extra.ignore
        # By default, don't allow fields to be reassigned after parsing.
        allow_mutation = False