BaseMiddleware

faststream.BaseMiddleware

BaseMiddleware(msg, /, *, context)

Bases: Generic[PublishCommandType, AnyMsg]

A base middleware class.

Source code in faststream/_internal/middlewares.py

def __init__(
    self,
    msg: AnyMsg | None,
    /,
    *,
    context: "ContextRepo",
) -> None:
    self.msg = msg
    self.context = context

msg instance-attribute

msg = msg

context instance-attribute

context = context

on_receive async

on_receive()

Hook to call on message receive.

Source code in faststream/_internal/middlewares.py

async def on_receive(self) -> None:
    """Hook to call on message receive."""

after_processed async

after_processed(exc_type=None, exc_val=None, exc_tb=None)

Asynchronously called after processing.

Source code in faststream/_internal/middlewares.py

async def after_processed(
    self,
    exc_type: type[BaseException] | None = None,
    exc_val: BaseException | None = None,
    exc_tb: Optional["TracebackType"] = None,
) -> bool | None:
    """Asynchronously called after processing."""
    return False

on_consume async

on_consume(msg)

This option was deprecated and will be removed in 0.7.0. Please, use consume_scope instead.

Source code in faststream/_internal/middlewares.py

async def on_consume(
    self,
    msg: "StreamMessage[AnyMsg]",
) -> "StreamMessage[AnyMsg]":
    """This option was deprecated and will be removed in 0.7.0. Please, use `consume_scope` instead."""
    return msg

after_consume async

after_consume(err)

This option was deprecated and will be removed in 0.7.0. Please, use consume_scope instead.

Source code in faststream/_internal/middlewares.py

async def after_consume(self, err: Exception | None) -> None:
    """This option was deprecated and will be removed in 0.7.0. Please, use `consume_scope` instead."""
    if err is not None:
        raise err

consume_scope async

consume_scope(call_next, msg)

Asynchronously consumes a message and returns an asynchronous iterator of decoded messages.

Source code in faststream/_internal/middlewares.py

async def consume_scope(
    self,
    call_next: "AsyncFuncAny",
    msg: "StreamMessage[AnyMsg]",
) -> Any:
    """Asynchronously consumes a message and returns an asynchronous iterator of decoded messages."""
    err: Exception | None = None
    try:
        result = await call_next(await self.on_consume(msg))

    except Exception as e:
        err = e

    else:
        return result

    finally:
        await self.after_consume(err)

on_publish async

on_publish(msg)

This option was deprecated and will be removed in 0.7.0. Please, use publish_scope instead.

Source code in faststream/_internal/middlewares.py

async def on_publish(
    self,
    msg: PublishCommandType,
) -> PublishCommandType:
    """This option was deprecated and will be removed in 0.7.0. Please, use `publish_scope` instead."""
    return msg

after_publish async

after_publish(err)

This option was deprecated and will be removed in 0.7.0. Please, use publish_scope instead.

Source code in faststream/_internal/middlewares.py

async def after_publish(
    self,
    err: Exception | None,
) -> None:
    """This option was deprecated and will be removed in 0.7.0. Please, use `publish_scope` instead."""
    if err is not None:
        raise err

publish_scope async

publish_scope(call_next, cmd)

Publish a message and return an async iterator.

Source code in faststream/_internal/middlewares.py

async def publish_scope(
    self,
    call_next: Callable[[PublishCommandType], Awaitable[Any]],
    cmd: PublishCommandType,
) -> Any:
    """Publish a message and return an async iterator."""
    err: Exception | None = None
    try:
        result = await call_next(await self.on_publish(cmd))

    except Exception as e:
        err = e

    else:
        return result

    finally:
        await self.after_publish(err)