Shiny Reactivity

Question

I\'ve got an application with a large number of parameters. Each parameters has lots of granularity which make finding the desired one a pain. This causes the reactive porti

Answer 1

• change getY so that all but the first line is wrapped in isolate({ ... })
• change submitButton to actionButton
• add a line inside of renderPlot to read the new actionButton

Answer 2

The answer was given by Joe Cheng in a comment above, but seeing that the OP had difficulty understanding it, I write it out explicitly below, for the record:

# ui.R

library("shiny")
shinyUI(
  pageWithSidebar(
    headerPanel("Example")
    ,
    sidebarPanel(
      sliderInput("N", "Number of Samples", min = 2, max = 1000, value = 100)
      ,
      actionButton("action", "Resample")
    )
    ,  
    mainPanel(
      tabsetPanel(      
        tabPanel("Plot", plotOutput("plotSample"))
        ,
        id = "tabs1"
      )
    )
  )
)

# server.R

library("shiny")
shinyServer(
  function(input, output, session) { 
    Data <- reactive({
        input$action
        isolate({ 
            return(rnorm(input$N))
            return(x)
        })
    })
  output$plotSample <-renderPlot({
      plot(Data())
    } , height = 400, width = 400
  )
})

Note that having input$action inside reactive(), where "action" is the actionButton's inputID, is enough to trigger a new rendering of the plot. So you need only one actionButton.