withProgress: Reporting progress (functional API)
In BBEST: Bayesian Estimation of Incoherent Neutron Scattering Backgrounds

Description Usage Arguments Details See Also Examples

Reports progress to the user during long-running operations.

withProgress(
  session,
  expr,
  min = 0,
  max = 1,
  env = parent.frame(),
  quoted = FALSE
)

setProgress(message = NULL, detail = NULL, value = NULL)

`session`	The Shiny session object, as provided by `shinyServer` to the server function.
`expr`	The work to be done. This expression should contain calls to `setProgress`.
`min`	The value that represents the starting point of the progress bar. Must be less than `max`.
`max`	The value that represents the end of the progress bar. Must be greater than `min`.
`env`	The environment in which `expr` should be evaluated.
`quoted`	Whether `expr` is a quoted expression (this is not common).
`message`	A single-element character vector; the message to be displayed to the user, or `NULL` to hide the current message (if any).
`detail`	A single-element character vector; the detail message to be displayed to the user, or `NULL` to hide the current detail message (if any). The detail message will be shown with a de-emphasized appearance relative to `message`.
`value`	Single-element numeric vector; the value at which to set the progress bar, relative to `min` and `max`. `NULL` hides the progress bar, if it is currently visible.

This package exposes two distinct programming APIs for working with progress. withProgress and setProgress together provide a simple function-based interface, while the Progress reference class provides an object-oriented API.

Use withProgress to wrap the scope of your work; doing so will cause a new progress panel to be created, and it will be displayed the first time setProgress is called. When withProgress exits, the corresponding progress panel will be removed.

Generally, withProgress/setProgress should be sufficient; the exception is if the work to be done is asynchronous (this is not common) or otherwise cannot be encapsulated by a single scope. In that case, you can use the Progress reference class.

progressInit, Progress

## Not run: 
# server.R
shinyServer(function(input, output, session) {
  output$plot <- renderPlot({
    withProgress(session, min=1, max=15, {
      setProgress(message = 'Calculation in progress',
                  detail = 'This may take a while...')
      for (i in 1:15) {
        setProgress(value = i)
        Sys.sleep(0.5)
      }
    })
    plot(cars)
  })
})

## End(Not run)