ipc (version 0.1.4)

AsyncProgress: A progress bar object where inc and set are usable within other processes

Description

A progress bar object where inc and set are usable within other processes

A progress bar object where inc and set are usable within other processes

Methods

Public methods

• AsyncProgress$new()

• AsyncProgress$getMax()

• AsyncProgress$getMin()

• AsyncProgress$sequentialClose()

• AsyncProgress$set()

• AsyncProgress$inc()

• AsyncProgress$close()

• AsyncProgress$clone()

---

Method new()

Creates a new progress panel and displays it.

Usage

AsyncProgress$new(
  ...,
  queue = shinyQueue(),
  millis = 250,
  value = NULL,
  message = NULL,
  detail = NULL
)

Arguments

...

Additional parameters to be passed to Shiny::Progress

queue

A Queue object for message passing

millis

How often in milliseconds should updates to the progress bar be checked for.

value

A numeric value at which to set the progress bar, relative to min and max.

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.

---

Method getMax()

Returns the maximum

Usage

AsyncProgress$getMax()

---

Method getMin()

Returns the minimum

Usage

AsyncProgress$getMin()

---

Method sequentialClose()

Removes the progress panel and destroys the queue. Must be called from main process.

Usage

AsyncProgress$sequentialClose()

---

Method set()

Updates the progress panel. When called the first time, the progress panel is displayed.

Usage

AsyncProgress$set(value = NULL, message = NULL, detail = NULL)

Arguments

value

A numeric value at which to set

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.

---

Method inc()

Like set, this updates the progress panel. The difference is that inc increases the progress bar by amount, instead of setting it to a specific value.

Usage

AsyncProgress$inc(amount = 0.1, message = NULL, detail = NULL)

Arguments

amount

the size of the increment.

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.

---

Method close()

Fires a close signal and may be used from any process.

Usage

AsyncProgress$close()

---

Method clone()

The objects of this class are cloneable with this method.

Usage

AsyncProgress$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Details

An async compatible wrapper around Shiny's progress bar. It should be instatiated from the main process, but may be closed, set and incremented from any process.

Examples

## Only run examples in interactive R sessions
if (interactive()) {
library(shiny)
library(future)
plan(multisession)
ui <- fluidPage(
  actionButton("run","Run"),
  tableOutput("dataset")
)

server <- function(input, output, session) {

  dat <- reactiveVal()
  observeEvent(input$run, {
    progress <- AsyncProgress$new(session, min=1, max=15)
    future({
      for (i in 1:15) {
        progress$set(value = i)
        Sys.sleep(0.5)
      }
      progress$close()
      cars
    }) %...>% dat
    NULL #return something other than the future so the UI is not blocked
  })

  output$dataset <- renderTable({
    req(dat())
  })
}

shinyApp(ui, server)
}