router

Streamlit Extras Router

Router is a class to manage pages and routing to them, either via browser query strings or via other paths in your code.

Basic usage

Note that st.set_page_config must be called before getting the router.

import random
import streamlit as st
from streamlitextras.router import get_router

router = None
def main():
    global router
    pages = {
        "main": main_page,
        "other": another_page,
    }
    st.set_page_config(
        page_title="MyApp",
        layout="wide",
        initial_sidebar_state="auto"
    )
    router = get_router()
    router.delayed_init()  # This is required to make sure current Router stays in session state

    computed_chance = random.randrange(10)
    if computed_chance > 1:
        router.route()
    else:
        router.route("other", computed_chance)

def main_page(page_state = None):
    st.write("This is the main.")

def another_page(page_state = None):
    st.write(f"This is another page, you're lucky to be here. Number {page_state} lucky.")

if __name__ == "__main__":
    main()

This will set the browser query string to /?page_name=page_state and render the page function associated with that page name in pages.

router.route() takes the key from the pages dict as the first argument, and routes to that page, with no arguments will default to the first page in pages

Due to a streamlit bug not being able to read empty query strings, page_state will show as ~ in the browser URL if there is none.

Instead of using router.route() you can use router.show_route_view() which will bypass setting query strings and just run that page function:

computed_chance = random.randrange(10)
if computed_chance > 1:
    router.show_route_view()
else:
    router.show_route_view("other", computed_chance)

See the API docs for more usage options, such as setting a callable pre-route function, or passing extra page_state/dependencies to every page_function.

Advanced usage

Below is an implementation that uses a routes folder module to manage pages.

routes folder __init__.py

import streamlitextras

router: streamlitextras.router.Router
auth: streamlitextras.authenticator.Authenticator
cookie_manager: streamlitextras.cookiemanager.CookieManager

def __getattr__(name):
    if name == "cookie_manager":
        cookie_manager = streamlitextras.cookiemanager.get_cookie_manager()
        return cookie_manager
    elif name == "auth":
        auth = streamlitextras.authenticator.get_auth("my_cookie")
        return auth
    elif name == "router":
        router = streamlitextras.router.get_router(pages, pre_route)
        return router
    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")

from .preroute import pre_route
from .userpage import user_page
from .authpage import auth_page
from .mainpage import main_page

pages = {
    "main": main_page,
    "user": user_page,
    "auth": auth_page,
}

main.py

import os
import streamlit as st
from streamlitextras.authenticator.exceptions import AuthException
from streamlitextras.logger import log
st.set_page_config(
    page_title="",
    layout="wide",
    initial_sidebar_state="auto"
)
import routes # NOTE: This has to be imported after st.set_page_config()


router = None
auth = None
cookie_manager = None
def main() -> None:
    router = routes.router
    auth = routes.auth
    cookie_manager = routes.cookie_manager

    # This is required to make sure current instances stay in session_state
    auth.delayed_init()
    router.delayed_init()

    try:
        auth_status = auth.auth_status
        user = auth.current_user
        log.info(f"Auth status: {auth_status} - User: {user.localId if user else user}")
    except AuthException as e:
        log.error(f"Error checking auth_status {e}")
        return router.show_route_view("auth")

    if auth_status and user:
        router.show_route_view(redirect_page_names=["auth"])
    else:
        router.show_route_view("auth")

if __name__ == "__main__":
    main()

For full reference see the API docs.