How to extend 'text' field as well in Graph.ExtendData - or, how to use Plotly.restyle() instead in a clientside callback?

Dash Python
1

I have an animated graph that I update in a clientside callback. However, I want to update the text as well as the x and y values of the traces in Graph.extendData(), but it seems that that doesn’t work. Is there something I’m missing? Alternatively, is there a different method I should be using instead - for example it looks like Plotly.restyle() might do what I want (as per javascript - Plotly.js: update text of each node using restyle - Stack Overflow) but it isn’t clear to me how to do that.

Adopting the code from this post (python - Plotly/Dash display real time data in smooth animation - Stack Overflow), I’d like something like this, but where updating the text with extendData (or something else!) actually worked:

import dash
import dash_html_components as html
import dash_core_components as dcc
import numpy as np

from dash.dependencies import Input, Output, State

# Example data (a circle).
resolution = 1000
t = np.linspace(0, np.pi * 2, resolution)
x, y = np.cos(t), np.sin(t)
text = str(t)

# Example app.
figure = dict(data=[{'x': [], 'y': []}], text = [], layout=dict(xaxis=dict(range=[-1, 1]), yaxis=dict(range=[-1, 1])))
app = dash.Dash(__name__, update_title=None)  # remove "Updating..." from title
app.layout = html.Div([
    dcc.Graph(id='graph', figure=dict(figure)), dcc.Interval(id="interval", interval=25),
    dcc.Store(id='offset', data=0), dcc.Store(id='store', data=dict(x=x, y=y, text=text, resolution=resolution)),
])

# This makes the graph fail to draw instead of just extending the text as wel!
app.clientside_callback(
    """
    function (n_intervals, data, offset) {
        offset = offset % data.x.length;
        const end = Math.min((offset + 10), data.x.length);
        return [[{x: [data.x.slice(offset, end)], y: [data.y.slice(offset, end)], text: [data.text.slice(offset, end)]}, [0], 500], end]
    }
    """,
    [Output('graph', 'extendData'), Output('offset', 'data')],
    [Input('interval', 'n_intervals')], [State('store', 'data'), State('offset', 'data')]
)

if __name__ == '__main__':
    app.run_server()

Alternatively, is there a different method I should be using instead?