Adding custom form field validation for "register_user"

[sohomhm]

Hi @mkhorasani ,

First of all, thanks a ton for this essential package -- saves us a lot of time and effort!

Coming to my query, I have a very specific use case for my new user registration form -- I would like to restrict registration of those users who basically have an email id from a very specific domain (For ex: Just allowing user emails with @gmail.com domain)

I can see as per line#52, the email validation just checks whether it contains an @; I would like to add the specific domain as the validation to it along with the @ check!

Is there any way we can achieve this?

P.S. The custom form field validation should not be just on the email but may also extend for other fields as well!

[velicanu]

Yea you can definitely bring your own validation logic. Just redefine (or subclass) the Validator class and re-implement the name, username, or email validation logic as you see fit. Here's a minimal code example that changes email validation to allow only users from gmail domain:

import streamlit_authenticator as stauth
import yaml

class CustomValidator(stauth.validator.Validator):
    def validate_email(self, email: str) -> bool:
        return email.endswith("@gmail.com")

config = yaml.load("path/to/auth.yaml", Loader=yaml.SafeLoader)

authenticator = stauth.Authenticate(
    credentials=config["credentials"],
    cookie_name=config["cookie"]["name"],
    key=config["cookie"]["key"],
    cookie_expiry_days=config["cookie"]["expiry_days"],
    preauthorized=config["preauthorized"],
    validator=CustomValidator(),
)

[sohomhm]

Thanks a ton for the help! :100: