Function process

nextpy/app.py:880–935

Process an event. Args: app: The app to process the event for. event: The event to process. sid: The Socket.IO session id. headers: The client headers. client_ip: The client_ip. Yields: The state updates after processing the event.

(
    app: App, event: Event, sid: str, headers: Dict, client_ip: str
)

async def process(
    app: App, event: Event, sid: str, headers: Dict, client_ip: str
) -> AsyncIterator[StateUpdate]:
    """Process an event.

    Args:
        app: The app to process the event for.
        event: The event to process.
        sid: The Socket.IO session id.
        headers: The client headers.
        client_ip: The client_ip.

    Yields:
        The state updates after processing the event.
    """
    # Add request data to the state.
    router_data = event.router_data
    router_data.update(
        {
            constants.RouteVar.QUERY: format.format_query_params(event.router_data),
            constants.RouteVar.CLIENT_TOKEN: event.token,
            constants.RouteVar.SESSION_ID: sid,
            constants.RouteVar.HEADERS: headers,
            constants.RouteVar.CLIENT_IP: client_ip,
        }
    )
    # Get the state for the session exclusively.
    async with app.state_manager.modify_state(event.token) as state:
        # re-assign only when the value is different
        if state.router_data != router_data:
            # assignment will recurse into substates and force recalculation of
            # dependent ComputedVar (dynamic route variables)
            state.router_data = router_data
            state.router = RouterData(router_data)

        # Preprocess the event.
        update = await app.preprocess(state, event)

        # If there was an update, yield it.
        if update is not None:
            yield update

        # Only process the event if there is no update.
        else:
            if app._process_background(state, event) is not None:
                # `final=True` allows the frontend send more events immediately.
                yield StateUpdate(final=True)
                return

            # Process the event synchronously.
            async for update in state._process(event):
                # Postprocess the event.
                update = await app.postprocess(state, event, update)

                # Yield the update.
                yield update