Restart Shiny Session

Question

This seems like a very obvious question but I haven't found anything on the subject.

How can I refresh a shiny application (the equivalent of pressing F5, or clicking the "Reload App" button in RStudio)?

ui.R

 shinyUI(pageWithSidebar(
  headerPanel("Example"),
  sidebarPanel(
    actionButton("goButton", "Refresh")
  ),  
  mainPanel(
        h4("I would really like to refresh this please.")
    )   
))

server.R

shinyServer(function(input, output,session) { 
  observe({
    if(input$goButton==0) return(NULL)
    isolate({
      #
      #  I would like to refresh my session here with some sort of 
      #  function like session(refresh)...
    })
    })
})

I don't think I want to use stopApp() - I just want to refresh it such that it's in the same state as when it is loaded.

UPDATE

On the RStudio website, it shows here how to manage a user's session from the server. Specifically,

$ sudo rstudio-server suspend-session <pid>

Is there the equivalent function as the user, from within the app? In the documentation for session info (here), it says there is an onSessionEnded(callback) function. It would be good if there was a session.End() function which performs the above suspend-session function!

score 19 · Accepted Answer · edited Nov 17 '20 at 01:22

19

You can use the history.go(0) js-method to reload the page and thus reset the session, e.g. from a link:

p(HTML("<A HREF=\"javascript:history.go(0)\">Reset this page</A>"))

Furthermore you can use the shinyjs package to execute javascript from within the server:

library(shiny)
library(shinyjs)

jsResetCode <- "shinyjs.reset = function() {history.go(0)}" # Define the js method that resets the page

shinyApp(
  ui = fluidPage(
    useShinyjs(),                                           # Include shinyjs in the UI
    extendShinyjs(text = jsResetCode, functions = "reset"), # Add the js code to the page
    actionButton("reset_button", "Reset Page")
  ),

  server = function(input, output) {
    observeEvent(input$reset_button, {js$reset()})          # Call the method from
                                                            # somewhere within the server
  })

edited Nov 17 '20 at 01:22

DeanAttali

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answered Dec 02 '15 at 08:44

bubble

382
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4

Nice answer @bubble. As the author of shinyjs, I'd also like to add that if resetting all the inputs is sufficient (ie. get all the input values back to their initial state, instead of literally refreshing the page), then you can use the built-in shinyjs reset function – DeanAttali Dec 05 '15 at 03:12
Thank you for the feedback @daattali :) It was my first answer. – bubble Dec 07 '15 at 10:31
1

Nice answer, sorry for the delay. – Hamilton Blake May 19 '16 at 12:50

score 16 · Answer 2 · answered May 23 '20 at 19:42

16

The session has now a method to do the trick. Shinyjs is no longer required:

session$reload()

answered May 23 '20 at 19:42

Jan

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Which requires adding `session` to the server's `function()` arguments. – stragu Mar 02 '22 at 00:59

score 9 · Answer 3 · answered May 23 '17 at 14:19

You can add a refresh icon and popover to your app by including the following in your ui code:

library(shinyBS)

tags$a(href="javascript:history.go(0)", 
           popify(tags$i(class="fa fa-refresh fa-5x"),
                  title = "Reload", 
                  content = "Click here to restart the Shiny session",
                  placement = "right"))

It should give you this:

Restart Shiny Session

3 Answers3

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