Reading the content of a html.Textarea

Dash Python
1

This should be straightforward, but I can’t figure out how to access what the user has typed into a html.Textarea.

This is how I generate the component:

def text_area(id, rows=10, placeholder="..."):
    area = html.Textarea(
        id=id,
        className="textarea",
        placeholder=placeholder,
        rows=rows
    )
    return area

I am assuming that the text is stored in the value attribute, but that is always None.

2

You’re looking for dcc.Textarea rather than html.Textarea :+1:

https://dash.plot.ly/dash-core-components/textarea

1 Like
3

I just went down a rabbit hole of “I’m sure I’ve used this prop before why can’t I get a simple demo to work”

As a result if anyone ever wants to print out all available props from dash_html_component here is some example code:

import dash
import pprint
import dash_html_components as html

app = dash.Dash(__name__)

text_area = html.Textarea(
    id='test-textarea',
    className="textarea",
    placeholder='Type here..',
    rows=10
)

app.layout = html.Div([
    text_area,
    html.Br(),
    html.Pre(id='test-output')
])


inputs = {}
for available_property in text_area.available_properties:
    if all(not available_property.startswith(a) for a in text_area.available_wildcard_properties):
        inputs[available_property] = dash.dependencies.Input('test-textarea', available_property)

@app.callback(
    output=dash.dependencies.Output('test-output', 'children'),
    inputs=list(inputs.values())
)
def get_value_from_textarea(*args):
    return pprint.pformat(dict(zip(inputs.keys(), args)))

if __name__ == '__main__':
    app.run_server(debug=True, dev_tools_ui=True)
1 Like
4

:man_facepalming: okay thanks, that was it