Add filters to commandHandler

[jossalgon]

Add filters to CommandHandler.

Now you can filter commands, for example to separate a command from group and private or any filter you want.

updater = Updater(token=TG_TOKEN)
dp = updater.dispatcher

dp.add_handler(CommandHandler('start', start, filter_example))

where filter_example is:

def filter_example(msg):
    return msg.chat.type == 'private'

or

updater = Updater(token=TG_TOKEN)
dp = updater.dispatcher

dp.add_handler(CommandHandler('start', start, lambda msg: msg.chat.type == 'private'))

[Eldinnie]

I'm looking forward to this, but I think you will have to write some tests for this to get it pulled.

[jossalgon]

Do you mean a test on test_updater.py? like:
https://github.com/python-telegram-bot/python-telegram-bot/blob/master/tests/test_updater.py#L169-L185

I didn't find any more tests of commandHandler, thanks for the feedback.

[jh0ker]

@jossalgon Yes, indeed. Just add one test case where the filter allows the message and one test case where it doesn't, then we're good to merge I think 👍

[jossalgon]

Are the tests ok in this way?

[jh0ker]

Great, but the name of the two test functions says MessageHandler, not CommandHandler ^^

[jossalgon]

👍 sorry, the commit is now amended

[jh0ker]

I'll let the tests run through on Travis before merging, but it looks good. Thank you very much for your contribution :) Did you already add yourself to AUTHORS.rst?

[jossalgon]

Not yet, I'll add a commit with that and it's a pleasure to collaborate :)

[Eldinnie]

Would you mind adding me to authors to? I forgot and to make a single PR just for that :D
Pieter Schutz github.com/eldinnie

[jh0ker]

@Eldinnie I can just commit that directly to master, no need to piggyback it here @jossalgon ^^

[jh0ker]

anyways, tests look good so I'll merge now!