当“ R Shiny”中的动作按钮或滑块更改时，隐藏图

Question

I have a small Shiny app that generates some data whenever the New data button is pressed. The Show plot button shows a hidden plot. I would like the plot to be hidden again automatically whenever the New data button is pressed to make a new data set. A bonus would be for the plot to be hidden also as soon as the slider is changed. I am not looking for a toggle action.

I tried adapting this example that uses conditional panel but I could not successfully figure out how to correctly change the values$show between TRUE and FALSE .

library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      sliderInput(inputId = "number",
                  label = "Pick a number",
                  min = 6,
                  max = 12,
                  value = 8),
      actionButton("new_data",
                   "New data"),
      actionButton("show_plot",
                   "Show plot")
    ),
    mainPanel(
      tableOutput("char_table"),
      plotOutput(outputId = "car_plot")

    )
  )
)

server <- function(input, output) {

  t <- eventReactive(input$new_data, {
    r <- input$number
    c <- r - 1
    mat <- matrix(sample(0:1,r*c, replace=TRUE),r,c)
  })

  output$char_table <- renderTable({
    t()
  })

  p <- eventReactive(input$show_plot, {
    plot(cars)
  })
  output$car_plot <- renderPlot({
    p()
  })
}

shinyApp(ui = ui, server = server)

Answer 1

You can use a reactive value and a if to control the plot.

library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      sliderInput(inputId = "number",
                  label = "Pick a number",
                  min = 6,
                  max = 12,
                  value = 8),
      actionButton("new_data",
                   "New data"),
      actionButton("show_plot",
                   "Show plot")
    ),
    mainPanel(
      tableOutput("char_table"),
      plotOutput(outputId = "car_plot")

    )
  )
)

server <- function(input, output) {
  showPlot <- reactiveVal(FALSE)

  t <- eventReactive(input$new_data, {
    showPlot(FALSE)
    r <- input$number
    c <- r - 1
    mat <- matrix(sample(0:1,r*c, replace=TRUE),r,c)
  })

  output$char_table <- renderTable({
      t()
  })

  observeEvent(input$number, {
    showPlot(FALSE) 
  })

  observeEvent(input$show_plot, {
    showPlot(TRUE) 
  })

  output$car_plot <- renderPlot({
    if (showPlot())
      plot(cars)
  })
}

shinyApp(ui = ui, server = server)

Answer 2

Alternate solution using shinyjs which is handy in these situations.

library(shiny)
library(shinyjs)

ui <- fluidPage( shinyjs::useShinyjs(),
  sidebarLayout(
    sidebarPanel(
      sliderInput(inputId = "number",
                  label = "Pick a number",
                  min = 6,
                  max = 12,
                  value = 8),
      actionButton("new_data",
                   "New data"),
      actionButton("show_plot",
                   "Show plot")
    ),
    mainPanel(
      tableOutput("char_table"),
      plotOutput(outputId = "car_plot")

    )
  )
)

server <- function(input, output) {

  t <- eventReactive(input$new_data, {
    hide("car_plot")
    r <- input$number
    c <- r - 1
    mat <- matrix(sample(0:1,r*c, replace=TRUE),r,c)
  })

  output$char_table <- renderTable({
    t()
  })

  observeEvent(input$show_plot, {
    show("car_plot")
  })
  output$car_plot <- renderPlot({
    plot(cars)
  })
}

shinyApp(ui = ui, server = server)