Add chat_id in ChatMemberHandler to Filter Specific Chat(s) #4287

[uniquetrij]

closes #4287

Added a chat_id param to ChatMemberHandler to filter updates only from specified chat(s).

So, now instead of having to filter chat_id within the callback methods as the following,

async def member_callback_1(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    if update.chat_member.chat.id != <chat_id_1>:
        return
    ...

async def member_callback_2(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    if update.chat_member.chat.id != <chat_id_2>:
        return
    ...

you can now pass chat_id while declaring your ChatMemberHandler.

application.add_handler(
    ChatMemberHandler(member_callback_1, ChatMemberHandler.CHAT_MEMBER, chat_id=<chat_id_1>)
)

application.add_handler(
    ChatMemberHandler(member_callback_2, ChatMemberHandler.CHAT_MEMBER, chat_id=<chat_id_2>)
)

[Bibo-Joshi]

Thank you for the PR :) I left some comments below. Please also have a look at the failing doc build test. We can check the other tests after that if needed.

[Bibo-Joshi]

I personally find the negation a bit confusing. I would find it more intuitive to have a function __is_chat_allowed …

[uniquetrij]

Had to introduce this function only because pylint was failing with so many if conditions in check_update. Your suggestion to use update.effective_chat instead resolved it. So moved the condition back to check_update and removed this function altogether. Fixed the other issues as well. Thanks for your review and suggestions. Let me know if everything looks okay now :)

[Bibo-Joshi]

Thanks for the updates, LGTM now :)
before merging, let me just check if someone else from the dev team wants to review.

[harshil21]

LGTM

[Bibo-Joshi]

Thank you for the nice contribution!