dcc.Input bug with decimal values

[bperrenoud]

when using the input component with numbers and with a callback

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

app = dash.Dash()

app.layout = html.Div([
    dcc.Input(placeholder='Enter a value...',
        type='number',
        value=0,
        step=0.01,
        id='input_id',
        style={'float': 'left'}),
    html.Div(id='my-div')
])

@app.callback(
    Output(component_id='my-div', component_property='children'),
    [Input(component_id='input_id', component_property='value')]
)
def update_output_div(input_value):
    return 'You\'ve entered "{}"'.format(input_value)

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

Try entering decimal values with some 0s in the decimal part, for instance 0.001 or 4.1004:
When the callback is triggered, any ending 0 will be removed preventing you to finish writing the number

[chriddyp]

Looks like this bug was added in #100 , here:

dash-core-components/src/components/Input.react.js

Lines 34 to 36 in 9478e4f

	if (type === 'number') {
	setProps({value: Number(e.target.value)});
	}

For now, you can use type='text' and do the casting server-side in your dash app code

[ngnpope]

I think the best solution here is to debounce onChange for dcc.Input().
This will allow the user to finish what they are typing before the event handler triggers.

[moorepants]

I agree with @pope1ni, the input boxes shouldn't send numbers to the server before the user has finished typing them. I'm having this trouble when entering multi digit numbers. For example, if I want to enter 20 manually, 2 gets sent to the server before I finish typing.

[steven-murray]

Any timeline for this being fixed? It is very annoying! I'd rather not do the casting server-side because it makes it harder to let the user know what went wrong to fix it.

[valentijnnieman]

Version 0.37.0 now includes a new debounce prop on the input component, that when true, only sends back the data to the server upon 'Enter' or when losing focus. Hopefully this fixes the issues you've been having. I will close this issue now, assuming that the issue has been fixed. Thanks for your patience!

[vantaka2]

@valentijnnieman - Did .37 fix the issue? I'm using .38 and seeing this same bug.

[chriddyp]

@vantaka2 - Would you mind creating a new issue with a small, reproducable example? debounce=True is indeed the way to go here.