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

In ipc: Tools for Message Passing Between Processes

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

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.

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.

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)
}

ipc documentation built on Feb. 16, 2023, 6:01 p.m.