shiny (version 1.9.1)

showNotification: 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())

Value

An ID for the notification.

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.

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]
    })
  }
)
}