Controlling the state and title of st.expander()

I am new to streamlit, so there is probably an easy way to do this, but basically I have an expanding container in which I’m putting a login widget. I want to control the state of the login widget based on the authentication. It is initialized in the expanded state. On successful login, I want to minimize the expander and change the title of the expander to “Welcome {user name}”

I know session.state might help, but the only implementation I’ve found is to use a dedicated button to switch between the expander states. but that is not possible for the UI I want.
Any help?

1 Like

Hi @raghav_kaul,

Thanks for posting!

Here’s an implementation that you can modify to fit your requirements.

import streamlit as st

def main():
    st.title("Welcome to My Super Cool App")

    if 'is_logged_in' not in st.session_state:
        st.session_state['is_logged_in'] = False

    if st.session_state['is_logged_in']:
        with st.expander(label=f"Welcome {st.session_state['user_name']}", expanded=False):
            st.write("🎉 Hooray! You've unlocked the secret chamber of this app!")
        with st.expander(label="Please log in", expanded=True):
            user_name = st.text_input("Username")
            password = st.text_input("Password", type="password")

            if st.button("Login", on_click=login, args=(user_name, password)):

def login(user_name, password):
    if user_name == "User" and password == "supersecret":  # In real life, use secure password handling!
        st.session_state['is_logged_in'] = True
        st.session_state['user_name'] = user_name

# Kick off the app

Let me know if this is helpful.

1 Like

Hi @tonykip, thanks for replying! I think the implementation of the login widget might be a newer one(or older one I don’t know).
Please check my code and help me out with implementing your solution

so what I want to achieve is a command with which I can change the attributes(label and expanded) of login_widget, which I would write under if authentication status:

My confusion is arising from your use of a separate function for login, which is not the case in this repository. the passwords are hashed and the login authenticator is written in a different file. Thank you very much for your patience!

Can you please paste the code in a code block so I can copy it and also include the code for authentication? You can mask out any sensitive information or add dummy values.

code of the screenshot i sent you

    login_widget = st.expander(label="Login", expanded=True)
    with login_widget:  
        authenticator = setup_authenticator() 
        login_collumn,_,_ = st.columns((0.3,0.3,0.4))
        with login_collumn:
            name, authentication_status,username = authenticator.login('', 'main')

        # check authentication 
        if authentication_status: 
            st.write(f'Welcome *{name}*')   
            authenticator.logout('Logout', 'main')
        if authentication_status == False:
            st.error('Username/password is incorrect')

code for the setup_authenticator() function

import streamlit_authenticator as stauth

from utils.load import load_auth_config

def setup_authenticator():
    config = load_auth_config('auth_config.yaml')
    authenticator = stauth.Authenticate(
    return authenticator

the auth_config.yaml file is just a file with the username and hashed passwords which I’m assuming you wont need

and this is the load_auth_config() function

def load_auth_config(auth_config: str) -> Dict[Any, Any]:
    file_path = Path(get_project_root()) / f"config/{auth_config}"
    with as file:
        config = yaml.load(file, Loader=SafeLoader)
    return config

please note this code is old and not written by me and was done hastily so might not be the most efficient way to do this.

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