CODEWITHSUNDEEP
rshiny
Charles Stangor
Charles Stangor

Reputation: 304

Reset shiny reactive timer

I want to reset the reactive timer to zero and start counting to 10000 again.

If you press the reset button within 10s, "timer fires" should never print.

I thought this might work, but no.

require('shiny')
if (interactive()) {

  ui <- fluidPage(
    actionButton("reset_button", "Reset")
  )


  server <- function(input, output) {

    autoInvalidate <- reactiveTimer(10000)

    observe({
      autoInvalidate()
      print ("timer fires")      

    })

    observeEvent(input$reset_button, 
     {
       autoInvalidate <- reactiveTimer(10000)
       print("reset")
     }
    )

  }

  shinyApp(ui, server)
}

Upvotes: 2

Views: 1112

Answers (2)

Pork Chop
Pork Chop

Reputation: 29417

This should do:

library(shiny)
ui <- fluidPage(
  actionButton("reset_button", "Reset"),
  textOutput("text")
)

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

  v <- reactiveValues(timer = Sys.time()+5)

  observe({
    invalidateLater(100)
    if(v$timer <= Sys.time()){
      v$timer <- Sys.time()+5
      print("timer fires") 
    }
  })

  observeEvent(input$reset_button,{
    v$timer <- Sys.time()+5
    print("reset")
  })

}
shinyApp(ui, server)

Upvotes: 4

SeGa
SeGa

Reputation: 9809

I am not 100% sure I understand your desired behaviour. If you press "reset" should the timer start from 0 again, or should "timer fires" never be printed. Because with reactiveTimer or invalidateLater your code will re-execute every x milliseconds.

I came up with this little example. If you want "timer fires" never to appear when "reset" is pressed, you have to include the loopit() part. If you just want to reset the timer, then delete the lines with loopit().

require('shiny')
if (interactive()) {

  ui <- fluidPage(
    actionButton("reset_button", "Reset")
  )


  start = Sys.time()
  n=10000

  server <- function(input, output) {
    loopit <- reactiveVal(TRUE)

    observe({
      invalidateLater(n)
      if (loopit()) {
        print(paste("start: ", start))
        if (Sys.time() > start+(n/1000)) {
          print ("timer fires")      
        } 
      }
    })

    observeEvent(input$reset_button, {
      start <<- Sys.time()
      loopit(FALSE)
      print("reset")
    })
  }

  shinyApp(ui, server)
}

Upvotes: 1

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