title: unique session id for different dash sessions
body: <p>I would like to create unique session ids for each time a user opens the dash app in browser.</p>
  
  <p>I have been following the tutorial here:</p>
  
  <p><a href="https://dash.plot.ly/sharing-data-between-callbacks" rel="nofollow noreferrer">https://dash.plot.ly/sharing-data-between-callbacks</a></p>
  
  <p>This is my code:</p>
  
  <pre><code>import dash
  import dash_html_components as html
  import dash_core_components as dcc
  import flask
  import datetime 
  import uuid
  
  external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']
  
  app = flask.Flask(__name__)
  dash_app = dash.Dash(__name__,server=app,url_base_pathname="/",external_stylesheets=external_stylesheets)
  
  def serve_layout():
      session_id = str(uuid.uuid4())
      return html.Div([
      html.Div(session_id, id='session-id', style={'display': 'none'}),
      html.Div(dcc.Input(id="input_session_id",type="text",value=session_id))
      ])
  dash_app.layout = serve_layout()
  
  if __name__ == '__main__':
      app.run(host='0.0.0.0', debug=True, port=80)
  </code></pre>
  
  <p>It seems like the session ids are different if I use different computers but if I use the same computer, it will stay the same.</p>
  
  <p>Is there a way to generate an unique session each time an user opens the url for the dash app?</p>