How to create IF statement with reactive values in R ( Shiny )

Question

Beginner to R and shiny here! Tried to make a minimal working example... I want to check a condition on a reactive input value. What am I doing wrong?

librar         


        

Answer 1

The answer above from John Paul is certainly acceptable, but I thought you might like to see another way as a part of your learning process. I will let StackOverflow sort out which is more advisable.

library(shiny)

ui<-fluidPage(

  numericInput(inputId="a", label=NULL, value=0),
  textOutput(outputId="out")
)

server <- function(input, output) {
  state <- reactiveValues()

  observe({
    state$x <- input$a
    state$y <- ifelse(state$x < 4, 1, 0)
  })

  output$out <- renderText({ state$y })
}

shinyApp(ui = ui, server = server)