Closed
Description
In dash==2.18.0, the number of no_update returned must match the number of outputs. This is not true in earlier versions of Dash.
This can be resolved by making no_update match but is a regression.
Consider:
import dash
from dash import html, dcc, Input, Output, no_update
# Initialize the Dash app
app = dash.Dash(__name__)
# Define the layout
app.layout = html.Div(
[
dcc.Input(id="input-box", type="text", value=""),
html.Button("Submit", id="button"),
html.Div(id="output-1", children="Output 1 will be displayed here"),
html.Div(id="output-2", children="Output 2 will be displayed here"),
]
)
# Callback with two outputs
@app.callback(
Output("output-1", "children"),
Output("output-2", "children"),
Input("button", "n_clicks"),
Input("input-box", "value"),
)
def update_outputs(n_clicks, value):
if n_clicks is None:
return no_update
return "Hello", "world!"
# Run the app
if __name__ == "__main__":
app.run_server(debug=True)Dash 2.18
Dash 2.17
