Store something in state?

Dash Python
1

Hi,.
I’m trying to figure out how to use the Store component… just for something simple… so store a value in the session.

I’ve included the store in the layout like this:

app.layout = html.Div(children=[
    # session storage_type is cleared when the browser exit.
    dcc.Store(id='session', storage_type='session'),
    html.Div(id='output-confirm'),
    dcc.ConfirmDialog(
        id='confirm',
        message='Threshold Exceeded, please confirm',
    ),
    dcc.Graph(id='basic-interactions'),
    dcc.Interval(
        id='interval-component',
        interval=5 * 1000,  # in milliseconds
        n_intervals=0
    ),
    ...etc

Then I’m trying to use it in a callback…

@app.callback([Output('confirm', 'displayed'),
              Output('basic-interactions', 'figure')],
              [Input('interval-component', 'n_intervals')],
              [State('local', 'lastAlert')])

def update_figure(update_num, lastAlert):

But I get an error as follows…

dash.exceptions.NonExistentIdException:
Attempting to assign a callback to the
component with the id “local” but no
components with id “local” exist in the
app’s layout.

Here is a list of IDs in layout:
[‘session’, ‘output-confirm’, ‘confirm’, ‘basic-interactions’, ‘interval-component’, ‘click-data’]

Just wondering is my approach wrong? The code example in the docs is pretty confusing. I just want to do something basic… is there a simpler example?

Thanks

2

The Store you made has id='session' (which also happens to be its storage_type but that doesn’t matter), and the prop it uses to store info is 'data'. So State('session', 'data') is probably what you want.

3

Oh Doh…!
You’re right… sorry… should have been
State ('session'..

Thanks!