set the R config variable `plotly_domain` inside JS as `window.PLOTLY_ENV.BASE_URL`

[chriddyp]

In plotly.js, we use window.PLOTLY_ENV.BASE_URL (https://github.com/plotly/plotly.js/blob/master/src/plots/plots.js#L370) to determine which cloud to send the graph to. If the user set plotly_domain inside their R ENV, we need to set that in the JS window.PLOTLY_ENV.BASE_URL so that charts don't get sent outside the network.

[cpsievert]

Ah, good catch. And just out of curiosity, this would only apply if someone makes the plot locally, then clicks the "save and edit in cloud" in the modebar, right?

[chriddyp]

@cpsievert yup, that's right.