Dash: [BUG] error reporting callback definition errors

[alexcjohnson]

From https://community.plot.ly/t/multiple-callback-error/24981

Probably came from removing the MutableMapping mixin https://github.com/plotly/dash/pull/753

This app has bad IDs in the second callback:

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

series = [str(i) for i in range(20)]

all_options = {
    'group_1': series[1:5],
    'group_2': series[6:10],
    'group_3': series[11:-1],
}

app = dash.Dash()

app.layout = html.Div(children=[
    html.P([
        html.Label('Choose a group:'),
        dcc.Dropdown(
            id='groups_dropdown',
            options=[{'label': k, 'value': k} for k in all_options.keys()],
            value='group_1'
        )
    ], style=dict(width='400px')),

    html.P([
        html.Label('Choose a series:'),
        dcc.Dropdown(id='series_dropdown')
    ], style=dict(width='400px')),
])


@app.callback(Output('series_dropdown', 'options'),
              [Input('groups_dropdown', 'value')])
def set_series_options(selected_group):
    return [{'label': i, 'value': i} for i in all_options[selected_group]]


@app.callback(Output('series-dropdown', 'value'),
              [Input('series-dropdown', 'options')])
def set_series_value(available_options):
    return available_options[0]['value']


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

But the error is broken:

Traceback (most recent call last):
  File "f.py", line 40, in <module>
    [Input('series-dropdown', 'options')])
  File "/Users/alex/plotly/dash/dash/dash.py", line 1156, in callback
    self._validate_callback(output, inputs, state)
  File "/Users/alex/plotly/dash/dash/dash.py", line 865, in _validate_callback
    list(layout.keys()) + (
AttributeError: 'Div' object has no attribute 'keys'

[shoegazerstella]

Hi,
I am having the same issue. These are the libraries versions if it can help:

dash
dash-html-components==0.13.4
dash-core-components==0.42.1
dash-daq
dash-table==3.1.11

Does this depend only on the new version of dash? Or maybe the other components are related?

[alexcjohnson]

@shoegazerstella if the issue is what I think it is, it's specific to dash 1.0.0 via #753 - I expect we'll be able to fix this for the next release.

[Buyannemekh]

Hi, I'm running into the same problem. I'd like to follow up if this has fixed yet? Thank you.