dropdown 'label' doesn't render (seemingly) depending on 'value'

Hi, Possible bug report: Dropdown labels won’t render in the dropdown box if the corresponding ‘value’ for the label is a tuple.

In below example: selecting test_label0 will result in no rendering of test_label0 in the dropdown box. Selecting test_label1 will result in it correctly rending within the dropdown box. Expected behaviour: that label would always render in dropdown irrespective of value value.

# -*- coding: utf-8 -*-
import dash
import dash_core_components as dcc
import dash_html_components as html
import plotly.graph_objs as go

dropdown_options = [
        {'label':'test_label0', 'value':(0,'test_label0')},
        {'label':'test_label1', 'value':1},
        ]

app = dash.Dash()

app.layout = html.Div(children=[
    html.H1(children='dropdown_test'),

    dcc.Dropdown(
        id='dropdown',
        options=dropdown_options,
    )])

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

On OSX, install via pip in conda env:

dash                      0.19.0                    <pip>
dash-core-components      0.15.4                    <pip>
dash-html-components      0.8.0                     <pip>
dash-renderer             0.11.1                    <pip>
dash.ly                   0.17.3                    <pip>

[DBCerigo]

@ned2 sorry for the lack of response!

The “bug” (clearly not actually a bug) stopped, and I couldn’t track down what the change was.

But thanks for the response, and right that the issue is now closed 👍

[ned2]

I don’t seem to be able to reproduce this behaviour using your same Dash dependencies. Here’s the code I’m using:

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

dropdown_options = [
    {'label':'test_label1', 'value':'1'},
    {'label':'test_label2', 'value':'2'},
]

app = dash.Dash()

app.layout = html.Div([
    html.H1(children='dropdown_test'),
    dcc.Dropdown(
        id='dropdown',
        options=dropdown_options,
        value='1'
    ),
    html.Div(id='target')
])

@app.callback(Output('target', 'children'), [Input('dropdown', 'value')])
def callback2(value):
    print(type(value))
    return value

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

Note also that you should probably be providing an initial value for value when you initialize the Dropdown, otherwise it will get the value None on each initial page load.