Improve FSM.

aiogram/contrib/fsm_storage/memory.py

@@ -1,6 +1,6 @@
 import typing
 
-from ...dispatcher import BaseStorage
+from ...dispatcher.storage import BaseStorage
 
 
 class MemoryStorage(BaseStorage):
@@ -56,7 +56,7 @@ class MemoryStorage(BaseStorage):
         chat, user = self.check_address(chat=chat, user=user)
         user = self._get_user(chat, user)
         if data is None:
-            data = []
+            data = {}
         user['data'].update(data, **kwargs)
 
     async def set_state(self, *,

aiogram/dispatcher/dispatcher.py

@@ -15,7 +15,6 @@ from .storage import BaseStorage, DELTA, DisabledStorage, EXCEEDED_COUNT, FSMCon
 from .webhook import BaseResponse
 from .. import types
 from ..bot import Bot, bot
-from ..types.message import ContentType
 from ..utils.exceptions import TelegramAPIError, Throttled
 
 log = logging.getLogger(__name__)
@@ -509,6 +508,7 @@ class Dispatcher:
         :param kwargs:
         :return: decorated function
         """
+
         def decorator(callback):
             self.register_channel_post_handler(callback, *custom_filters, commands=commands, regexp=regexp,
                                                content_types=content_types, state=state, run_task=run_task, **kwargs)
@@ -699,6 +699,7 @@ class Dispatcher:
         :param run_task: run callback in task (no wait results)
         :param kwargs:
         """
+
         def decorator(callback):
             self.register_callback_query_handler(callback, *custom_filters, state=state, run_task=run_task, **kwargs)
             return callback
@@ -744,6 +745,7 @@ class Dispatcher:
         :param run_task: run callback in task (no wait results)
         :param kwargs:
         """
+
         def decorator(callback):
             self.register_shipping_query_handler(callback, *custom_filters, state=state, run_task=run_task, **kwargs)
             return callback

aiogram/dispatcher/filters/builtin.py

@@ -1,5 +1,4 @@
 import re
-import typing
 from _contextvars import ContextVar
 
 from aiogram import types
@@ -117,16 +116,26 @@ class StateFilter(BaseFilter):
     ctx_state = ContextVar('user_state')
 
     def __init__(self, dispatcher, state):
+        from aiogram.dispatcher.filters.state import State
+
         super().__init__(dispatcher)
-        if isinstance(state, str) or state is None:
-            state = (state,)
-        self.state = state
+        states = []
+        if not isinstance(state, (list, set, tuple, frozenset)) or state is None:
+            state = [state, ]
+        for item in state:
+            if isinstance(item, State):
+                states.append(item.state)
+            elif hasattr(item, 'state_names'):  # issubclass() cannot be used in this place
+                states.extend(item.state_names)
+            else:
+                states.append(item)
+        self.states = states
 
     def get_target(self, obj):
         return getattr(getattr(obj, 'chat', None), 'id', None), getattr(getattr(obj, 'from_user', None), 'id', None)
 
     async def check(self, obj):
-        if '*' in self.state:
+        if '*' in self.states:
             return {'state': self.dispatcher.current_state()}
 
         try:
@@ -137,11 +146,11 @@ class StateFilter(BaseFilter):
             if chat or user:
                 state = await self.dispatcher.storage.get_state(chat=chat, user=user)
                 self.ctx_state.set(state)
-                if state in self.state:
+                if state in self.states:
                     return {'state': self.dispatcher.current_state(), 'raw_state': state}
 
         else:
-            if state in self.state:
+            if state in self.states:
                 return {'state': self.dispatcher.current_state(), 'raw_state': state}
 
         return False

aiogram/dispatcher/filters/state.py

@@ -0,0 +1,95 @@
+from ..dispatcher import Dispatcher
+
+
+class State:
+    def __init__(self, state=None):
+        self.state = state
+
+    def __set_name__(self, owner, name):
+        if self.state is None:
+            self.state = owner.__name__ + ':' + name
+
+    def __str__(self):
+        return f"<State '{self.state}>'"
+
+    __repr__ = __str__
+
+    async def set(self):
+        state = Dispatcher.current().current_state()
+        await state.set_state(self.state)
+
+
+class MetaStatesGroup(type):
+    def __new__(mcs, name, bases, namespace, **kwargs):
+        cls = super(MetaStatesGroup, mcs).__new__(mcs, name, bases, namespace)
+
+        states = []
+        for name, prop in ((name, prop) for name, prop in namespace.items() if isinstance(prop, State)):
+            states.append(prop)
+
+        cls._states = tuple(states)
+        cls._state_names = tuple(state.state for state in states)
+
+        return cls
+
+    @property
+    def states(cls) -> tuple:
+        return cls._states
+
+    @property
+    def state_names(cls) -> tuple:
+        return cls._state_names
+
+
+class StatesGroup(metaclass=MetaStatesGroup):
+    @classmethod
+    async def next(cls) -> str:
+        state = Dispatcher.current().current_state()
+        state_name = await state.get_state()
+
+        try:
+            next_step = cls.state_names.index(state_name) + 1
+        except ValueError:
+            next_step = 0
+
+        try:
+            next_state_name = cls.states[next_step].state
+        except IndexError:
+            next_state_name = None
+
+        await state.set_state(next_state_name)
+        return next_state_name
+
+    @classmethod
+    async def previous(cls) -> str:
+        state = Dispatcher.current().current_state()
+        state_name = await state.get_state()
+
+        try:
+            previous_step = cls.state_names.index(state_name) - 1
+        except ValueError:
+            previous_step = 0
+
+        if previous_step < 0:
+            previous_state_name = None
+        else:
+            previous_state_name = cls.states[previous_step].state
+
+        await state.set_state(previous_state_name)
+        return previous_state_name
+
+    @classmethod
+    async def first(cls) -> str:
+        state = Dispatcher.current().current_state()
+        first_step_name = cls.states[0].state
+
+        await state.set_state(first_step_name)
+        return first_step_name
+
+    @classmethod
+    async def last(cls) -> str:
+        state = Dispatcher.current().current_state()
+        last_step_name = cls.states[-1].state
+
+        await state.set_state(last_step_name)
+        return last_step_name

examples/finite_state_machine_example.py

@@ -1,11 +1,13 @@
 import asyncio
+from typing import Optional
 
-from aiogram import Bot, types
+import aiogram.utils.markdown as md
+from aiogram import Bot, Dispatcher, types
 from aiogram.contrib.fsm_storage.memory import MemoryStorage
-from aiogram.dispatcher import Dispatcher
+from aiogram.dispatcher import FSMContext
+from aiogram.dispatcher.filters.state import State, StatesGroup
 from aiogram.types import ParseMode
 from aiogram.utils import executor
-from aiogram.utils.markdown import text, bold
 
 API_TOKEN = 'BOT TOKEN HERE'
 
@@ -17,10 +19,12 @@ bot = Bot(token=API_TOKEN, loop=loop)
 storage = MemoryStorage()
 dp = Dispatcher(bot, storage=storage)
 
+
 # States
-AGE = 'process_age'
-NAME = 'process_name'
-GENDER = 'process_gender'
+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'])
@@ -28,48 +32,41 @@ async def cmd_start(message: types.Message):
     """
     Conversation's entry point
     """
-    # Get current state
-    state = dp.current_state(chat=message.chat.id, user=message.from_user.id)
-    # Update user's state
-    await state.set_state(NAME)
+    # Set state
+    await Form.name.set()
 
     await message.reply("Hi there! What's your name?")
 
 
 # You can use state '*' if you need to handle all states
 @dp.message_handler(state='*', commands=['cancel'])
-@dp.message_handler(state='*', func=lambda message: message.text.lower() == 'cancel')
-async def cancel_handler(message: types.Message):
+@dp.message_handler(lambda message: message.text.lower() == 'cancel', state='*')
+async def cancel_handler(message: types.Message, state: FSMContext, raw_state: Optional[str] = None):
     """
     Allow user to cancel any action
     """
-    with dp.current_state(chat=message.chat.id, user=message.from_user.id) as state:
-        # Ignore command if user is not in any (defined) state
-        if await state.get_state() is None:
-            return
+    if raw_state is None:
+        return
 
-        # Otherwise cancel state and inform user about it
-        # And remove keyboard (just in case)
-        await state.reset_state(with_data=True)
-        await message.reply('Canceled.', reply_markup=types.ReplyKeyboardRemove())
+    # Cancel state and inform user about it
+    await state.finish()
+    # And remove keyboard (just in case)
+    await message.reply('Canceled.', reply_markup=types.ReplyKeyboardRemove())
 
 
-@dp.message_handler(state=NAME)
-async def process_name(message: types.Message):
+@dp.message_handler(state=Form.name)
+async def process_name(message: types.Message, state: FSMContext):
     """
     Process user name
     """
-    # Save name to storage and go to next step
-    # You can use context manager
-    with dp.current_state(chat=message.chat.id, user=message.from_user.id) as state:
-        await state.update_data(name=message.text)
-        await state.set_state(AGE)
+    await Form.next()
+    await state.update_data(name=message.text)
 
     await message.reply("How old are you?")
 
 
 # Check age. Age gotta be digit
-@dp.message_handler(state=AGE, func=lambda message: not message.text.isdigit())
+@dp.message_handler(lambda message: not message.text.isdigit(), state=Form.age)
 async def failed_process_age(message: types.Message):
     """
     If age is invalid
@@ -77,12 +74,11 @@ async def failed_process_age(message: types.Message):
     return await message.reply("Age gotta be a number.\nHow old are you? (digits only)")
 
 
-@dp.message_handler(state=AGE, func=lambda message: message.text.isdigit())
-async def process_age(message: types.Message):
+@dp.message_handler(lambda message: message.text.isdigit(), state=Form.age)
+async def process_age(message: types.Message, state: FSMContext):
     # Update state and data
-    with dp.current_state(chat=message.chat.id, user=message.from_user.id) as state:
-        await state.set_state(GENDER)
-        await state.update_data(age=int(message.text))
+    await Form.next()
+    await state.update_data(age=int(message.text))
 
     # Configure ReplyKeyboardMarkup
     markup = types.ReplyKeyboardMarkup(resize_keyboard=True, selective=True)
@@ -92,7 +88,7 @@ async def process_age(message: types.Message):
     await message.reply("What is your gender?", reply_markup=markup)
 
 
-@dp.message_handler(state=GENDER, func=lambda message: message.text not in ["Male", "Female", "Other"])
+@dp.message_handler(lambda message: message.text not in ["Male", "Female", "Other"], state=Form.gender)
 async def failed_process_gender(message: types.Message):
     """
     In this example gender has to be one of: Male, Female, Other.
@@ -100,10 +96,8 @@ async def failed_process_gender(message: types.Message):
     return await message.reply("Bad gender name. Choose you gender from keyboard.")
 
 
-@dp.message_handler(state=GENDER)
-async def process_gender(message: types.Message):
-    state = dp.current_state(chat=message.chat.id, user=message.from_user.id)
-
+@dp.message_handler(state=Form.gender)
+async def process_gender(message: types.Message, state: FSMContext):
     data = await state.get_data()
     data['gender'] = message.text
 
@@ -111,10 +105,10 @@ async def process_gender(message: types.Message):
     markup = types.ReplyKeyboardRemove()
 
     # And send message
-    await bot.send_message(message.chat.id, text(
-        text('Hi! Nice to meet you,', bold(data['name'])),
-        text('Age:', data['age']),
-        text('Gender:', data['gender']),
+    await bot.send_message(message.chat.id, md.text(
+        md.text('Hi! Nice to meet you,', md.bold(data['name'])),
+        md.text('Age:', data['age']),
+        md.text('Gender:', data['gender']),
         sep='\n'), reply_markup=markup, parse_mode=ParseMode.MARKDOWN)
 
     # Finish conversation