"Processing..." feedback

[nuferates]

When the Run (and also Generate and preview files) buttons are clicked, a red 'Processing' warning (or a red light, or an hourglass) can be used to indicate that it is actually working. Particularly for complex models with high bootstrap samples, it might take a while. Impatiently, I happened to click 3-4 times on the Run button to see if it is working. I experienced that it calculated the same thing 3-4 times ( every time the results went gray while the next computation was being carried on). So some feedback to the user showing it started computing the first time he/she clicks the Run button may be helpful.

[aalfons]

There is minimal visual feedback in some cases: when there is already output shown, it is greyed out until the new output is ready. But this is only there if the user previously computed something, so I fully agree that some visual indication that things are computed would greatly enhance the experience.

I think @AuroreAA has a lot of experience with existing options for this in shiny.

[AuroreAA]

Two main solutions are possible:

• if you don't want to use another package, you have the function withProgress() but you need to put it inside each render* call: https://shiny.posit.co/r/articles/build/progress/
• otherwise you can use the shinybusy package and just states one time in the ui that you want an indicator each time shiny is busy: https://cran.r-project.org/web/packages/shinybusy/vignettes/shinybusy.html

@aalfons what do you prefer?