R Shiny - Hiding an Output When a Value Changes-CodePudding

I Would like to make a form type Shiny app where the output is shown when a user clicks and action button, but the output is subsequently hidden if an input values changes.

Here is an example:

library(shiny)
library(shinyjs)

ui <- fluidPage(
  radioButtons("myRadioButton", label = h4("Radio Input"),
               choices = list("A" = 0,
                              "B" = 1,
                              "C" = 2),
               selected = character(0)),
  
  numericInput("myNumericInput", label = h4("Numeric Input"),
               value = NA, min = 0, max = 50, step = 1),
  
  actionButton("submit", "Submit"),
  
  textOutput("myOutput")
)


server <- function(input, output, session){
  
  score <- reactive({
    scoreOut <- paste(input$myRadioButton, input$myNumericInput)
    })
  
  observeEvent(input$myRadioButton, {
    hide("myOutput")
    })
  
  observeEvent(input$myNumericInput, {
    hide("myOutput")
  })
  
  observeEvent(input$submit, {
    show("myOutput")
    output$myOutput <- renderText({
      paste("This is your value:", score())
    })
  })
  
}

shinyApp(ui, server)

So in the above example the output displays after "Submit" is clicked. What I would like is if you go back and change say the radio or numeric input, the output disappears until "Submit" is clicked again.

CodePudding user response：

You missed the useShinyjs() in the UI to load the JavaScript required to execute the hide function:

library(shiny)
library(shinyjs)

ui <- fluidPage(

  # load required Java Script
  useShinyjs(),

  radioButtons("myRadioButton",
    label = h4("Radio Input"),
    choices = list(
      "A" = 0,
      "B" = 1,
      "C" = 2
    ),
    selected = character(0)
  ),
  numericInput("myNumericInput",
    label = h4("Numeric Input"),
    value = NA, min = 0, max = 50, step = 1
  ),
  actionButton("submit", "Submit"),
  textOutput("myOutput")
)


server <- function(input, output, session) {
  score <- reactive({
    scoreOut <- paste(input$myRadioButton, input$myNumericInput)
  })

  observeEvent(input$myRadioButton, {
    hide("myOutput")
  })

  observeEvent(input$myNumericInput, {
    hide("myOutput")
  })

  observeEvent(input$submit, {
    show("myOutput")
    output$myOutput <- renderText({
      paste("This is your value:", score())
    })
  })
}

shinyApp(ui, server)