unable to set NumberInput to None from a callback

[leberber]

unable to set NumberInput to None from a callback

[jpatte46]

Came here to raise the same issue. For some reason the value is being removed in the backend (shown in my example by printing the value), but it remains in the front end.

from dash import callback, Dash, html, Input, Output, no_update
import dash_mantine_components as dmc

app = Dash(__name__)
app.layout = html.Div([
        dmc.NumberInput(
            label="Enter a number",
            id="number"
        ),
        dmc.Button(
            children='clear inputs',
            id='clear',
            n_clicks=0
        ),
        html.Div(
            id="value"
        )
])


@callback(
    Output("number", "value"),
    Input("clear", "n_clicks"),
)
def update_value(n_clicks):
    if n_clicks == 0:
        return no_update
    if n_clicks > 0:
        return None


@callback(
    Output('value', 'children'),
    Input("number", "value"),
)
def print_value(number):
    return html.P(f'NumberInput Value: {number}')


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

[snehilvj]

If you are using the latest 0.13 alpha releases, then the way to clear a number input is to set its value an empty string instead of None.

[leberber]

Thank you @snehilvj I have installed v 0.13 and it works