Conditional reactive/eventReactive

Question

I would like to add a checkbox (input$autorefresh) in my shiny application to control where my data input is auto updated (=reactive()) at every change, or whether it is only updated when a button (=input$refresh) is pushed. The idea is described in the following code, which I however didn't expect to work. I could use reactive() together with a conditional isolate(), but since I have many inputs, that is not very elegant. Any ideas?

if (input$autorefresh==TRUE){
    dataInput <- reactive({
      dosomething    
    })
} else {
    dataInput <- eventReactive(input$refresh,{
      dosomething
    })
}

Pork Chop Pork Chop · Accepted Answer · 2018-06-25T10:07:58

Are you looking for something like this?

library(shiny)

ui <- fluidPage(
  checkboxInput("autorefresh","autorefresh", F),
  actionButton("refresh","refresh"),
  mainPanel(plotOutput("plot"))
)

autoInvalidate <- reactiveTimer(1000)

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

  data <- reactive({
    input$refresh
    data <- plot(rnorm(100),type="l",col="red")

    if(input$autorefresh){
      autoInvalidate()
      return(data)
    }
    return(data)
  })

  output$plot <- renderPlot({
    data()
  })
}

runApp(shinyApp(ui = ui, server = server))

Conditional reactive/eventReactive

1 Answers