FSM doesn't work when I run aiogram with fastapi - python-3.x

Question

I have a problem with fsm using aiogram with Fastapi. I ran the code from aiogram_fsm_example, but changed the long-polling to the Fastapi implementation. Here's the code I've got:
import logging
from fastapi import FastAPI, Request
import aiogram.utils.markdown as md
from aiogram import Bot, Dispatcher, types
from aiogram.contrib.fsm_storage.memory import MemoryStorage
from aiogram.dispatcher import FSMContext
from aiogram.dispatcher.filters import Text
from aiogram.dispatcher.filters.state import State, StatesGroup
from aiogram.types import ParseMode
from aiogram.utils import executor
logging.basicConfig(level=logging.INFO)
API_TOKEN = "here's the bot token"
bot = Bot(token=API_TOKEN)
# For example use simple MemoryStorage for Dispatcher.
storage = MemoryStorage()
dp = Dispatcher(bot, storage=storage)
# States
class Form(StatesGroup):
name = State() # Will be represented in storage as 'Form:name'
age = State() # Will be represented in storage as 'Form:age'
gender = State() # Will be represented in storage as 'Form:gender'
#dp.message_handler(commands='start')
async def cmd_start(message: types.Message):
"""
Conversation's entry point
"""
# Set state
await Form.name.set()
await message.reply("Hi there! What's your name?")
#dp.message_handler(state=Form.name)
async def process_name(message: types.Message, state: FSMContext):
"""
Process user name
"""
async with state.proxy() as data:
data['name'] = message.text
await Form.next()
await message.reply("How old are you?")
# Check age. Age gotta be digit
#dp.message_handler(lambda message: not message.text.isdigit(), state=Form.age)
async def process_age_invalid(message: types.Message):
"""
If age is invalid
"""
return await message.reply("Age gotta be a number.\nHow old are you? (digits only)")
#dp.message_handler(lambda message: message.text.isdigit(), state=Form.age)
async def process_age(message: types.Message, state: FSMContext):
# Update state and data
await Form.next()
await state.update_data(age=int(message.text))
# Configure ReplyKeyboardMarkup
markup = types.ReplyKeyboardMarkup(resize_keyboard=True, selective=True)
markup.add("Male", "Female")
markup.add("Other")
await message.reply("What is your gender?", reply_markup=markup)
#dp.message_handler(lambda message: message.text not in ["Male", "Female", "Other"], state=Form.gender)
async def process_gender_invalid(message: types.Message):
"""
In this example gender has to be one of: Male, Female, Other.
"""
return await message.reply("Bad gender name. Choose your gender from the keyboard.")
#dp.message_handler(state=Form.gender)
async def process_gender(message: types.Message, state: FSMContext):
async with state.proxy() as data:
data['gender'] = message.text
# Remove keyboard
markup = types.ReplyKeyboardRemove()
# And send message
await bot.send_message(
message.chat.id,
md.text(
md.text('Hi! Nice to meet you,', md.bold(data['name'])),
md.text('Age:', md.code(data['age'])),
md.text('Gender:', data['gender']),
sep='\n',
),
reply_markup=markup,
parse_mode=ParseMode.MARKDOWN,
)
# Finish conversation
await state.finish()
# my changes
app = FastAPI()
#app.get("/")
async def root():
return "ok"
#app.post("/")
async def process_update(request: Request):
update = await request.json()
update = types.Update(**update)
print("incoming", update)
await dp.process_update(update)
But when I run that with uvicorn (uvicorn main:app) and send /start command to the bot, the backend throws this error:
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/uvicorn/protocols/http/h11_impl.py", line 373, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/uvicorn/middleware/proxy_headers.py", line 75, in __call__
return await self.app(scope, receive, send)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/fastapi/applications.py", line 208, in __call__
await super().__call__(scope, receive, send)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/applications.py", line 112, in __call__
await self.middleware_stack(scope, receive, send)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/routing.py", line 656, in __call__
await route.handle(scope, receive, send)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/routing.py", line 259, in handle
await self.app(scope, receive, send)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/starlette/routing.py", line 61, in app
response = await func(request)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/fastapi/routing.py", line 226, in app
raw_response = await run_endpoint_function(
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/fastapi/routing.py", line 159, in run_endpoint_function
return await dependant.call(**values)
File "/home/oleh/projects/tg_bot_test_fsm/./main.py", line 124, in process_update
await dp.process_update(update)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/aiogram/dispatcher/dispatcher.py", line 257, in process_update
return await self.message_handlers.notify(update.message)
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/aiogram/dispatcher/handler.py", line 116, in notify
response = await handler_obj.handler(*args, **partial_data)
File "/home/oleh/projects/tg_bot_test_fsm/./main.py", line 38, in cmd_start
await Form.name.set()
File "/home/oleh/projects/tg_bot_test_fsm/.venv/lib/python3.8/site-packages/aiogram/dispatcher/filters/state.py", line 56, in set
state = Dispatcher.get_current().current_state()
AttributeError: 'NoneType' object has no attribute 'current_state'
As far as I understood: there's a state in the dispatcher that is not created somewhy when I use the dp.process_update() function.
When I run that with long_polling - everything works fine, but I need so much to run it with Fastapi.
Is there a way to set up the state manually? Or I just do not process it correctly?
P.S. I run it in the WSL Ubuntu 20.04 LTS. Python version is 3.8.10, aiogram - 2.15, uvicorn - 0.15.0 and Fastapi - 0.70.0.
SOLVED: if you're using Fastapi with aiogram and trying FSM, you need to set state in another way, with state.set_state(Form.name) function. My working code of start method looks like that:
#dp.message_handler(commands='start', state="*")
async def cmd_start(message: types.Message, state: FSMContext):
"""
Conversation's entry point
"""
# Set state
await state.set_state(Form.name)
await message.reply("Hi there! What's your name?")

Answer 1

It's enough to set current context for Dispatcher
dp = Dispatcher(bot, storage=storage)
Dispatcher.set_current(dp)