Allowing users to download CSV on click

Dash Python
9

I believe that you can update this by adding URL parameters to the href property of your html.A component.

For example:

@app.callback(Output('my-link', 'href'), [Input('my-dropdown', 'value')])
def update_link(value):
    return '/dash/urlToDownload?value={}'.format(value)

@app.server.route('/dash/urlToDownload') 
def download_csv():
    value = flask.request.args.get('value')
    # create a dynamic csv or file here using `StringIO` 
    # (instead of writing to the file system)
    strIO = StringIO.StringIO()
    strIO.write('You have selected {}'.format(value)) 
    strIO.seek(0)    
    return send_file(strIO,
                     mimetype='text/csv',
                     attachment_filename='downloadFile.csv',
                     as_attachment=True)

but of course, if your file is small, you can just fill out the href property directly as in Download raw data - #8 by chriddyp without doing this in a @server.route.

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