Calling API methods sequentially is cool, but how to react when, for example, a new message arrives? This page deals with updates and how to handle such events in Pyrogram. Let’s have a look at how they work.
First, let’s define what are these updates. As hinted already, updates are simply events that happen in your Telegram account (incoming messages, new members join, bot button presses, etc…), which are meant to notify you about a new specific state that has changed. These updates are handled by registering one or more callback functions in your app using Handlers.
Each handler deals with a specific event and once a matching update arrives from Telegram, your registered callback function will be called back by the framework and its body executed.
Registering a Handler¶
To explain how handlers work let’s examine the one which will be in charge for handling
updates coming from all around your chats. Every other kind of handler shares the same setup logic and you should not
have troubles settings them up once you learn from this section.
The most elegant way to register a message handler is by using the
from pyrogram import Client app = Client("my_account") @app.on_message() def my_handler(client, message): message.forward("me") app.run()
The defined function
my_handler, which accepts the two arguments (client, message), will be the function that gets
executed every time a new message arrives.
You can also have asynchronous handlers; you only need to define the callback function using
async def and call API
methods by placing
await in front of them:
@app.on_message() async def my_handler(client, message): await message.forward("me")
You can mix
async def handlers as much as you need, Pyrogram will still work concurrently and
efficiently regardless of what you choose.
add_handler() method takes any handler instance that wraps around your defined callback
function and registers it in your Client. It is useful in case you want to programmatically add handlers (or in case,
for some reason, you don’t like to use decorators).
from pyrogram import Client from pyrogram.handlers import MessageHandler def my_function(client, message): message.forward("me") app = Client("my_account") my_handler = MessageHandler(my_function) app.add_handler(my_handler) app.run()
The same about asynchronous handlers applies for
async def my_function(client, message): await message.forward("me")
From now on, you’ll see examples using synchronous code (i.e.: without
await, unless when actually
relevant). This is done to keep snippets concise and more readable. Once you get the idea behind a feature, you can
easily turn examples asynchronous later on.