Script() Error

[ajmendez]

I would like to add a <script></script> tag with some dynamic code to incorporate another module that was already created. Here is some sample code that reproduces this bug:

import dash
import dash_html_components as html

app = dash.Dash()

app.layout = html.Div([
    html.Script('alert(1);', type='text/javascript')
])

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

Loading this page in Chrome does not bring up an alert dialog as expected. Running alert(1); from the console does bring up an alert so it is not related to any adblocker. I tried adding async=True and defer=True, but the code does not seem to run.

dash.version
'0.17.7'
dcc.version
'0.6.0'
html.version
'0.7.0'

[chriddyp]

I believe that this is an underlying issue with React (facebook/react#654).

Could you use app.scripts.append_script (as in https://plot.ly/dash/external-resources) instead? That will append the script to the actual HTML that gets served, rather than rendering it after page load through React.

[ajmendez]

That does look to be the issue.

The app.scripts.append_script workaround does not work for my application as I am configuring a second JS module with updated data as it is running. Do you have any recommendations on how to pass some JS variable through dash that does not use the html.Script() tag?

Edit: Is this fixable by adding a componentWillMount() method to generateComponent() for <script> tags? This may fix the html.Script() function:

1. https://stackoverflow.com/questions/34424845/adding-script-tag-to-react-jsx
2. https://github.com/blueberryapps/react-load-script

[chriddyp]

Dash Plugin Components are the recommended way to do this.