Dash app does not load assets and app.index_string

Dash Python
22

My assets is not working with dcc.Location:

Using dcc.Location as mentioned here: Multi-Page Apps and URL Support

I would like to assign my assets folder at run-time:

index.py

# Path managers
from pathlib import Path
CURRENT_PATH = Path(__file__)
CURRENT_DIR= CURRENT_PATH.parents[0]

from app import app

app.layout = html.Div([
    dcc.Location(id='url', refresh=False),
    html.Div(id='page-content')
])

@app.callback(Output('page-content', 'children'),
              Input('url', 'pathname'))
def display_page(pathname):
    if pathname == '/app':
        app.title = "title"
        app.assets_url_path= CURRENT_DIR.joinpath('app').joinpath('assets')
        return app.layout
    else:
        return '404'

if __name__ == '__main__':
    app.run_server(debug=True)

app.py

import dash
import dash_bootstrap_components as dbc

external_stylesheets = [dbc.themes.SIMPLEX, 'https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css']
app = dash.Dash( external_stylesheets=external_stylesheets
                , suppress_callback_exceptions=True
                , update_title='Loading...'
                , serve_locally=True
)
server = app.server

tree

-prj/
|    |-app.py
|    |-index.py
|    |-app/
|    |    |-app.py
|    |    |-assets/
|    |    |       |-"*".css

Unfortunately this configuration is not working. Any ideas?
Thx!

Update:
Looks like it doesn’t work because it assets_folder is a read-only variable:

image
image838×439 23.7 KB

So, is it only possible to have one assets folder for all the apps which follows URL Routing and Multiple Apps | Dash for Python Documentation | Plotly ? Therefore no customization app by app?

Thx