showNotification: Show or remove a notification

In rstudio/shiny: Web Application Framework for R

Show or remove a notification

Description

These functions show and remove notifications in a Shiny application.

Usage

showNotification(
  ui,
  action = NULL,
  duration = 5,
  closeButton = TRUE,
  id = NULL,
  type = c("default", "message", "warning", "error"),
  session = getDefaultReactiveDomain()
)

removeNotification(id, session = getDefaultReactiveDomain())

Arguments

ui	Content of message.
action	Message content that represents an action. For example, this could be a link that the user can click on. This is separate from ui so customized layouts can handle the main notification content separately from action content.
duration	Number of seconds to display the message before it disappears. Use NULL to make the message not automatically disappear.
closeButton	If TRUE, display a button which will make the notification disappear when clicked. If FALSE do not display.
id	A unique identifier for the notification. id is optional for showNotification(): Shiny will automatically create one if needed. If you do supply it, Shiny will update an existing notification if it exists, otherwise it will create a new one. id is required for removeNotification().
type	A string which controls the color of the notification. One of "default" (gray), "message" (blue), "warning" (yellow), or "error" (red).
session	Session object to send notification to.

Value

An ID for the notification.

Examples

## Only run examples in interactive R sessions
if (interactive()) {
# Show a message when button is clicked
shinyApp(
  ui = fluidPage(
    actionButton("show", "Show")
  ),
  server = function(input, output) {
    observeEvent(input$show, {
      showNotification("Message text",
        action = a(href = "javascript:location.reload();", "Reload page")
      )
    })
  }
)

# App with show and remove buttons
shinyApp(
  ui = fluidPage(
    actionButton("show", "Show"),
    actionButton("remove", "Remove")
  ),
  server = function(input, output) {
    # A queue of notification IDs
    ids <- character(0)
    # A counter
    n <- 0

    observeEvent(input$show, {
      # Save the ID for removal later
      id <- showNotification(paste("Message", n), duration = NULL)
      ids <<- c(ids, id)
      n <<- n + 1
    })

    observeEvent(input$remove, {
      if (length(ids) > 0)
        removeNotification(ids[1])
      ids <<- ids[-1]
    })
  }
)
}

rstudio/shiny documentation built on Nov. 8, 2024, 6 a.m.