Opening httpgd plot in external window through VSCode Workbench proxy server

[keithn]

When using VSCode on Posit Workbench with R plots configured to open using httpgd, I get an option to open the plot in an external window. That link will fail, somewhat predictably, because the link is to a localhost address and Workbench is accessed over the internet. Doing this will start a proxy server to get around this, but I can't get httpgd to work through the proxy server - initially because the URL in the proxy server is incomplete, but even when this is corrected, it doesn't seem to display plots.

Steps to recreate:

1. In Posit Workbench, open a VSCode session
2. Install httpgd
3. in VSCode settings, activate that R plots should open in httpgd:

   "r.plot.useHttpgd": true
   

4. In an R Interactive session, create a simple plot, e.g.

   plot(1:10)
   

5. Hover a mouse over the plot that appears, then choose "open in external browser" in the menu that appears above the plot. This will open a new tab that should fail.
   
   
6. In the RStudio/Posit Workbench menu, find the proxied server for "R". This will open a new tab that should display a 404. Leave this page open for now and return to VSCode.
   
7. In the R console run httpgd::hgd_url() and note the slug of the address. In this example the slug would be live?token=LylcTruU

   httpgd::hgd_url()
   ## [1] "http://127.0.0.1:40705/live?token=LylcTruU"
   

8. Go back to the page from step 6 and add the slug from step 7 to the end of the URL. Load the new address. The httpgd layout should appear, but no plots seem to be present.
   
   

I can get this to work on Visual Studio Code running locally, but can't seem to get plots to appear in Workbench. I'm not sure whether this is a httpgd issue or a configuration setting I need to change in Posit Workbench or VSCode for the proxied servers to work slightly differently.

Does anyone have ideas on where to look next in diagnosing this issue?

Thanks

[edavidaja]

Try using rserver-url to generate the address of the plot you want to visit:

https://docs.posit.co/ide/server-pro/user/posit-workbench/guide/python.html#url-prefixes