Using `fundi` for Dependency Injection in Event Handlers

[kuyugama]

Checklist

• I believe the idea is awesome and would benefit the framework
• I have searched in the issue tracker for similar requests, including closed ones

Description

Dependency injection is a powerful and convenient design pattern — and with FunDI, integrating it becomes effortless.

Since this library supports Python up to 3.9, the best way to include it as an optional dependency is like so:

pip install pyrofork[fundi]

---

Proposed Integration Example

from fundi import from_, FromType
from pyrogram import Client, filters
from pyrogram.types import Message


app = Client("my_account")


def require_user_mention(message: FromType[Message]) -> str:
    user = message.from_user

    if user.username is not None:
        return f"{user.mention}(@{user.username}|{user.id})"
    return f"{user.mention}({user.id})"


@app.on_message(filters.private)
async def hello(
    message: FromType[Message],
    mention: str = from_(require_user_mention),
):
    await message.reply(f"Hello, {mention}!")

---

🛠 How It Works

• The mention argument is automatically injected via from_(), which tells FunDI to resolve it using require_user_mention.
• FromType[Message] is a type hint that marks the message as an injectable Pyrogram context.
• require_user_mention is a plain function (sync or async) that accepts Message and returns a formatted string.

---

This approach keeps your handlers clean, modular, and readable.
FunDI handles the wiring — you just write logic.