Error loading react-dom@15.4.2

[radumas]

I've deployed a Dash app to Heroku and the page was loading fine on my development computer, but my colleagues ran into errors loading the page. The error I'm getting in the console at the moment is:
mighty-savannah-97969.herokuapp.com/:24 GET https://unpkg.com/react-dom@15.4.2/dist/react-dom.min.js
Playing with URLs at unpkg, I see that 15.4.1 and 15.5.1 exist.

[jimaek]

You can use jsDelivr instead https://cdn.jsdelivr.net/npm/react-dom@15.4.2/dist/react-dom.min.js

It's more reliable and built to be production ready, without such problems.

[radumas]

Indeed the problem appears to be with unpkg. Now bundle.js is struggling to be delivered.

How do I change the javascript sources in Dash?

This happens due to plotly/dash-renderer#11

[ned2]

The react javascript files are included within the dash-renderer package rather than dash itself. I've submitted this PR plotly/dash-renderer#12 to update the react files to 15.6.1.

If you look at the changes you'll see how to point to the javascript file you want.

[chriddyp]

For now, you can render the files locally without relying on the CDN with

app.css.config.serve_locally = True
app.scripts.config.serve_locally = True

[ned2]

Ah, so now I see what is meant by local CSS/JS is not supported. I've just been adding them with eg app.css.append_css({"external_url": '/static/css/foo.css'}) which has been working fine, however setting app.css.config.serve_locally = True now means that Dash can't find the file. As I get this UserWarning:

A local version of /static/css/foo.css is not available

Strangely it's finding local javascript files fine. Perhaps this wants to be a separate issue...

[radumas]

Can confirm that

app.css.config.serve_locally = True
app.scripts.config.serve_locally = True

works on heroku as well.

Thanks @chriddyp !

[chriddyp]

FYI - The original issue (failures serving react-dom from unpkg cdn) is being tracked here: unpkg/unpkg#54