Add example for new FSM.

examples/finite_state_machine_example.py

@@ -0,0 +1,127 @@
+import asyncio
+
+from aiogram import Bot, types
+from aiogram.dispatcher import Dispatcher
+from aiogram.dispatcher.storage import MemoryStorage
+from aiogram.types import ParseMode
+from aiogram.utils.markdown import text, bold
+
+API_TOKEN = 'BOT TOKEN HERE'
+
+loop = asyncio.get_event_loop()
+bot = Bot(token=API_TOKEN, loop=loop)
+storage = MemoryStorage()
+dp = Dispatcher(bot, storage=storage)
+
+# States
+AGE = 'process_age'
+NAME = 'process_name'
+GENDER = 'process_gender'
+
+
+@dp.message_handler(commands=['start'])
+async def cmd_start(message: types.Message):
+    """
+    Entry point to conversation
+    """
+    # Get current state
+    state = dp.current_state(chat=message.chat.id, user=message.from_user.id)
+    # Update user state
+    await state.set_state(NAME)
+
+    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):
+    """
+    Allow to cancel any action
+    """
+    with dp.current_state(chat=message.chat.id, user=message.from_user.id) as state:
+        if await state.get_state() is None:
+            return
+        await state.reset_state(with_data=True)
+        await message.reply('Canceled.', reply_markup=types.ReplyKeyboardRemove())
+
+
+@dp.message_handler(state=NAME)
+async def process_name(message: types.Message):
+    """
+    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 message.reply("How old are you?")
+
+
+# Check age. Age must be is digit
+@dp.message_handler(state=AGE, func=lambda message: not message.text.isdigit())
+async def failed_process_age(message: types.Message):
+    """
+    If age is in invalid format
+    """
+    return await message.reply("Age should be a number.\nHow old are you?")
+
+
+@dp.message_handler(state=AGE, func=lambda message: message.text.isdigit())
+async def process_age(message: types.Message):
+    # 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))
+
+    # Configure ReplyKeyboardMarkup
+    markup = types.ReplyKeyboardMarkup(resize_keyboard=True)
+    markup.add("Male", "Female")
+    markup.add("Other")
+
+    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"])
+async def failed_process_sex(message: types.Message):
+    """
+    Sex must be always (in this example) is one of: Male, Female, Other.
+    """
+    return await message.reply("Bad gender name. Choose you gender from keyboard.")
+
+
+@dp.message_handler(state=GENDER)
+async def process_sex(message: types.Message):
+    state = dp.current_state(chat=message.chat.id, user=message.from_user.id)
+
+    data = await state.get_data()
+    data['sex'] = message.text
+
+    # Remove keyboard
+    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('Sex:', data['sex']),
+        sep='\n'), reply_markup=markup, parse_mode=ParseMode.MARKDOWN)
+
+    # Finish conversation
+    await state.finish()
+
+
+async def main():
+    # Skip old updates
+    count = await dp.skip_updates()
+    print(f"Skipped {count} updates.")
+    await dp.start_pooling()
+
+
+if __name__ == '__main__':
+    try:
+        loop.run_until_complete(main())
+    except KeyboardInterrupt:
+        loop.stop()