[BUG] ClickData callback not triggering when clicking the same segment of pie chart

[wompo]

Describe your context
Please provide us your environment so we can easily reproduce the issue.

dash                 1.12.0
dash-core-components 1.10.0
dash-html-components 1.0.3
dash-renderer        1.4.1

• if frontend related, tell us your Browser, Version and OS

  • OS: Windows 10
  • Browser: chrome
  • Version: 83.0.4103.97 (Official Build) (64-bit)

Describe the bug

When using pie chart clickData as an input for a callback, it does not trigger when clicking the same segment twice (or multiple times) in a row.

Expected behavior

I would expect the callback to trigger again with the same clickData.

Simple app

A simple app to help reproduce the bug.

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

labels = ['Oxygen','Hydrogen','Carbon_Dioxide','Nitrogen']
values = [4500, 2500, 1053, 500]

app = dash.Dash(__name__)

app.layout = html.Div([
    dcc.Graph(
        id='pie',
        figure={
            'data': [{
                'values': values,
                'labels': labels,
                'type': 'pie'
            }]
        }
    ),
    html.Pre(id='clickDataDisplay')
])

@app.callback(
    Output('clickDataDisplay', 'children'),
    [Input('pie', 'clickData')]
)
def display_click_data(clickData):
    print("Processing click data.")
    return json.dumps(clickData, indent=2)

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

[codebicycle]

It affects bar charts as well as pie charts.
Actually, it affects all charts supported by dcc.Graph, starting with Dash version 1.11.0.

From Dash v1.11.0 release notes:

"A user interaction which returns the same property value as was previously present will not trigger the component to re-render, nor trigger callbacks using that property as an input."

Are there any workarounds to trigger a callback when clicking on the same section of a graph again?

[ValeriyaGriffiths]

I've got the same problem in dash 1.13.4. Any updates regarding a fix or a workaround would be very much appreciated.

[panizoeva]

Same issue here in environment:

dash                      1.17.0       
dash-core-components      1.13.0             
dash-html-components      1.1.1   
dash-renderer             1.8.3  
dash-table                4.11.0   

[nukescott]

still broken in:
dash 1.19.0
dash-core-components 1.15.0
dash-html-components 1.1.2
dash-renderer 1.9.0
dash-table 4.11.2

[alexcjohnson]

We've been discussing internally whether there's a better way to handle this, but as a workaround in dash 1.19, due to #1525, you should be able to set clickData to None or some such as the output of your callback, then repeated clicks will register.

@app.callback(
    Output('clickDataDisplay', 'children'),
    Output('pie', 'clickData'),
    Input('pie', 'clickData')
)
def display_click_data(clickData):
    print("Processing click data.")
    return json.dumps(clickData, indent=2), None

[nukescott]

Adding an Output with clickData, and returning None does indeed avoid the problem. Thanks so much!

[pmkroeker]

We've been discussing internally whether there's a better way to handle this, but as a workaround in dash 1.19, due to #1525, you should be able to set clickData to None or some such as the output of your callback, then repeated clicks will register.

@app.callback(
    Output('clickDataDisplay', 'children'),
    Output('pie', 'clickData'),
    Input('pie', 'clickData')
)
def display_click_data(clickData):
    print("Processing click data.")
    return json.dumps(clickData, indent=2), None

When I try this I get a an error in the browser.

"Same Input and Output"

The same solution was proposed for this issue, but the same problem happened. Is there a way to prevent those errors? They cause the entire dashboard to not render.

Using dash 1.18. Is that possibly the problem?

EDIT:

Yes that was the problem, upgrading to 1.19 fixed it.

[nphausg]

It works on dash:2.7.1

[gvwilson]

Hi - we are tidying up stale issues and PRs in Plotly's public repositories so that we can focus on things that are most important to our community. If this issue is still a concern, please add a comment letting us know what recent version of our software you've checked it with so that I can reopen it and add it to our backlog. (Please note that we will give priority to reports that include a short reproducible example.) If you'd like to submit a PR, we'd be happy to prioritize a review, and if it's a request for tech support, please post in our community forum. Thank you - @gvwilson

[JulianoLagana]

This is still a problem in dash 2.15.0.