Not firing callback "n_clicks" from "dbc.Button" at every page refresh

Dash Python
1

Hi everyone,
I’m currently developing a dashboard that uses several pages, using dbc.nav to navigate between pages.
The layout is basically something like (i’m translating from Julia so there might be some typos) :

app.layout = html.Div([
    dcc.Location(id="url"),
    dbc.Navlink(id="page-home", href="/home")
    dbc.Navlink(id="page-visu", href="/visu")
    dcc.Store(id="store"),
    html.Div(id='page_content')
])

With callbacks

@app.callback(
    Output("page-content", 'children'),
    Input("url", "pathname")
)
def render_content(pathname):
    if pathname = "/home":
        return homePageLayout
    elif pathname == "/visu":
        return visuPageLayout

Inside homePageLayout, i want to have a button that loads data on clicks, we have then something like

visuPageLayout = html.Div([dbc.Button(id="load-button")])

with the callbacks

@app.callback(Output("store", "data"), [Input("load-button", "n_clicks")])
def load_data(n_clicks):
    if not (n_clicks is None):
        return my_data

So, when i go to Home page and load data, I can go to Visu page and use those data.
However, when I go back to Home, since the load button callback is fired with None value and return nothing, dcc.Store is emptied and I have to reload data…
One solution could be to load data even if n_clicks is None, but in my case it takes about ten seconds to load those data, and I want to load data only if i click on load button.

Is there anyway to prevent load_button callback on every Homepage refresh ? It would prevent dcc.Store to be emptied each time.
If not, is there any other solution to implement what I want to do ? (ie : load data with button on a children page, and use those data on an other children page).
Much thanks !

2

I don’t know how to write subject as resolved, but using PreventUpdate works fine !