Python Plotly: Sankey is not updated on dcc.Interval

Dash Python
1

I need to animate a Plotly’s Sankey but it doesn’t update with the new data. A Sunburst plot based on the same data is OK, as you can see in this example.

Am I missing something here?

(If your dash server is slow, don’t forget to increase interval in dcc.Interval to a bigger value in msec, otherwise the callback is called again before the previous call is completed).

import plotly.graph_objs as go

import dash
import dash_html_components as html
import dash_core_components as dcc
from dash.dependencies import Output, Input
import random

app = dash.Dash(__name__)
app.layout = html.Div(
    [
        dcc.Graph(
            id="fig_sunburst",
            figure=go.Figure(),
            animate=True,
        ),
        dcc.Graph(
            id="fig_sankey",
            figure=go.Figure(),
            animate=True,
        ),

        dcc.Interval(
            id=f"update",
            interval=1000,
            n_intervals=0
        ),
    ],
)

@app.callback(
    Output('fig_sunburst', 'figure'),
    Output('fig_sankey', 'figure'),
    Input('update', 'n_intervals')
)
def traces_update(n_intervals):
    print(f"update {n_intervals}")
    
    # random data
    a1 = random.randint(10, 100)
    a2 = random.randint(10, 100)
    a3 = random.randint(10 ,100)
    a0 = a1+a2+a3
    
    b1 = random.randint(10, 100)
    b2 = random.randint(10, 100)
    b0 = b1+b2
    
    tot = a0+b0
    
    fig_sunburst = go.Figure(
        go.Sunburst(
            ids=['tot', 'a0', 'a1', 'a2', 'a3', 'b0', 'b1', 'b2'],
            labels=['tot', 'a0', 'a1', 'a2', 'a3', 'b0', 'b1', 'b2'],
            parents=['', 'tot', 'a0', 'a0', 'a0', 'tot', 'b0', 'b0'],
            values=[tot, a0, a1, a2, a3, b0, b1, b2],
            branchvalues="total",
        )
    )
    fig_sunburst.update_layout(go.Layout(width=400, height=400,
                                 margin=dict(t=20, l=20, r=20, b=20),))
        
    fig_sankey = go.Figure(
        go.Sankey(
            node=dict(
                label=['tot', 'a0', 'a1', 'a2', 'a3', 'b0', 'b1', 'b2'],
            ),
            link=dict(
                source=[0, 0, 1, 1, 1, 5, 5],
                target=[1, 5, 2, 3, 4, 6, 7],
                value=[a0, b0, a1, a2, a3, b1, b2],
            ),
        )
    )

    fig_sankey.update_layout(go.Layout(width=400, height=400,
                                 margin=dict(t=20, l=20, r=20, b=20),))
    
    return fig_sunburst, fig_sankey

app.run_server()

Also Posted without answer in Stackoverflow (python - Sankey is not updated on callback - Stack Overflow)

2

It must be a bug, because the first time takes the figure from the callback.

I don’t see any reason to not taking the figured that the callback sent after that.

I printed the output and is changing the value in the figure.

:thinking: