I am trying to introduce and synchronize a progress bar in an R Shiny app. This is a chunk from the main server function:

# Simulation Logic
observeEvent(input$calc_tax_prop_Button, {
  progress <- shiny::Progress$new()
  on.exit(progress$close())

  progress$set(message = "Running Simulation", detail = "Please wait...", value = 0)

  # Continuous back-and-forth movement of progress bar
  for (i in 1:10) {
    for (j in seq(0, 1, by = 0.1)) {
      progress$set(value = j)
      Sys.sleep(0.1)
    }
    for (j in seq(1, 0, by = -0.1)) {
      progress$set(value = j)
      Sys.sleep(0.1)
    }
  }

  # Actual script execution
  source("./Scripts/Scenarios.R")  # ←- Other script to execute 
  showNotification("Simulation is done!", duration = NULL)
})

When I press the button which activates this code, I face a problem. Namely, I can see the progress indicator as shown below, but the issue is that the part for calling other scripts (source(“./Scripts/Scenarios.R”)) is not activated.

To summarize, the progress bar goes back and forth but is not connected with the activation of this line: source(“./Scripts/Scenarios.R”).

Namely, when I press the button which activates this code, I want to see the progress indicator moving back and forth until this line (source(“./Scripts/Scenarios.R”)) finishes executing. At the end, I want to see the notification showNotification(“Simulation is done!”, duration = NULL).

Can anybody please help me solve this problem?