Duplicate callback when rerunning cell in databricks

Dash Python
1

Hi. Running databricks_dash on Databricks, when I run an app containing a callback it produces a duplicate callback error if I rerun the app.run cell.

Example code:

def create_fig(dataitem):
    df = pd.DataFrame({'col1': [1,2,3,4,5],
                     'col2': [6,7,8,9,10]
                     })
    df = df[df['col1'] > dataitem]
    fig = go.Figure()
    fig.add_trace(go.Scatter(x=df['col1'],
                           y=df['col2']))
    return fig             

radioit = html.Div(dcc.RadioItems(options=[1,2,3,4,5], value=5, id='radio'))

app = DatabricksDash(__name__, external_stylesheets=[dbc.themes.MINTY])

app.layout = dbc.Container(
    [
        html.H1("Test chart"),
        html.Br(),
        dbc.Row(dbc.Col(radioit),),
        html.Br(),
        dbc.Row(dbc.Col(dcc.Graph(id='line-chart'))),

    ], fluid=True
)

@callback(
    Output(component_id='line-chart', component_property='figure'),
    Input(component_id='radio', component_property='value'),
)
def append_own_data(
                    dataitem, 
                    ):

    return create_fig(dataitem)

app.run(debug=True)

When I run this cell for the first time it renders the app correctly, but if I rerun the cell in databricks I get the error duplicate callback.

Error message:

⛑️
Duplicate callback outputs
15:32:57
In the callback for output(s):
  line-chart.figure
Output 0 (line-chart.figure) is already in use.
To resolve this, set `allow_duplicate=True` on
duplicate outputs, or combine the outputs into
one callback function, distinguishing the trigger
by using `dash.callback_context` if necessary.
2

Hello @JamieG,

Welcome to the community!

I havent use databricks_dash, but have you tried using @app.callback instead of @callback?